-
DAY1 2/5 Risk Area Posted
From
Mike Powell@618:250/1 to
All on Mon Aug 4 08:32:48 2025
ACUS01 KWNS 041258
SWODY1
SPC AC 041256
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0756 AM CDT Mon Aug 04 2025
Valid 041300Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN AND CENTRAL HIGH PLAINS...
...SUMMARY...
Thunderstorms with severe gusts and hail will be possible today and
tonight from parts of the northern Rockies into the Dakotas and central/southern High Plains.
...Central High Plains...
Early morning surface analysis shows upper 50s dewpoints in place
across eastern CO, western KS, and western NE, with slightly lower
dewpoints across the NE Panhandle. Moist, southerly low-level flow
will help increase dewpoints across the region throughout the day,
likely resulting in upper 50s to low 60s dewpoints during the
afternoon despite strong heating and boundary-layer mixing. This
should result in a strongly buoyant but minimally capped airmass
across the region by the late afternoon. Additionally, low-level
southeasterly flow will veer to northwesterly in the mid levels,
resulting in moderate to strong deep-layer vertical shear and an
overall wind profile that favors supercells. As such, there is
conditional risk for severe thunderstorms. However, the forcing
mechanism for convective initiation is uncertain.
Upper ridging that currently extends from the Southwest into the
northern High Plains is expected to persist throughout the day, with
heights likely rising across the central High Plains. A shortwave
trough currently moving through the Great Basin is expected to move
within the northern periphery of this ridging, reaching the central
Rockies by this afternoon. Even so, given that heights are forecast
to rise across the central High Plains, the downstream influence of
this wave into the central High Plains will likely be minimal. This
overall lack of larger scale ascent leads to uncertainty regarding
storm coverage since more mesoscale factors, such as low-level
convergence along the lee troughing and weak low-level upslope flow,
will be the mechanisms for convective initiation. High-resolution
guidance offers varied storm coverage, with more recent HRRR runs
(i.e. 06-08Z) keeping the area largely free of storms versus earlier
runs (i.e. 00Z) which show scattered coverage. However, these drier
and less convective HRRR runs appear to be outliers compared to all
the other available guidance, and the general expectation is that
low-level convergence and upslope flow across the Black Hill
vicinity should be enough for scattered convective initiation.
As mentioned previously, the overall environment supports supercells
capable of large to very large hail and strong gusts. Any supercells
that develop could last for a few hours, but should eventually trend
towards a more linear mode with one or more clusters evolving across western/central NE and northeast CO this evening. Aided by a 40+ kt
low-level jet, continued upscale growth should support these
clusters of strong to severe storms into the overnight hours where
damaging winds will be possible.
...Northern Rockies into eastern Montana...
Shortwave trough currently moving through southern OR is forecast to
continue northeastward through the northern Rockies today and
tonight, while becoming increasingly negatively tilted. Ascent
attendant to this wave will interact with a modest buoyant airmass
from central ID into central MT, resulting in scattered to numerous thunderstorms across the region. Initially more cellular storms are
expected across the higher terrain of central ID and western MT with
eventual cold pool amalgamation resulting in one or two
eastward/northeastward progressing clusters across central and
eastern MT. Some hail is possible with the more cellular storms, but
damaging gusts appear to be the greater severe risk. Sufficient
severe storm coverage is anticipated across central and eastern MT
to merit introducing 15% wind probabilities.
...Southern High Plains...
Strong heating along a lee trough could support isolated
thunderstorm development from the Raton Mesa into southeast
CO/northeast NM. The thermodynamic environment here will be similar
to areas farther north, with large buoyancy (3000+ J/kg MLCAPE) and
40-50 kt of effective shear anticipated. A supercell mode is
expected initially with any storms that mature, with large hail,
damaging gusts, and a brief tornado possible. Storm maintenance into
the OK/TX Panhandles is possible, particularly given the
strengthening low-level jet.
...Central/Southeast Texas...
A decaying MCS continues to push southward/southeastward across
central TX at 35 kt. Isolated damaging gusts will remain possible
with this system over the next hour or two, but warming cloud tops
and lowering echo tops suggest this system will continue to weaken.
Additional storm development is possible along the western portion
of the outflow, but low-level stability should mitigate updraft strength.
..Mosier/Bentley.. 08/04/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Tue Aug 5 08:52:38 2025
ACUS01 KWNS 051244
SWODY1
SPC AC 051242
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Tue Aug 05 2025
Valid 051300Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
NORTH AND SOUTH DAKOTA...
...SUMMARY...
Thunderstorms associated with a threat for severe gusts and large
hail will be possible across parts of the Dakotas today into this
evening.
...Northern Plains...
Warm-air advection showers and thunderstorms are ongoing this
morning across the western Dakotas, where the western edge of the
low-level jet overlaps the eastern edge of the steep mid-level lapse
rates. These storms will likely continue northeastward this morning,
perhaps even expanding in coverage, as the low-level jet persists
and large-scale ascent attendant to an approaching shortwave trough strengthens. Occasionally strong updrafts could produce hail and a
damaging gust or two.
Cloud cover and outflow associated with these storms could result in
an effective warm front extending from a weak low over western SD
eastward across central and eastern SD. The exact location and
sharpness of this front remain uncertain. Given that the shortwave
trough will likely remain well west of the region, low-level
convergence near this boundary as well as the surface low should
both be areas where convective initiation is most likely this
afternoon. Ample buoyancy and vertical shear will be in place for
supercells with the initial development, with large hail and
damaging gusts as the primary risks. Stronger low to mid-level flow
may be in place across eastern SD, contributing to greater low-level
shear and relatively higher tornado potential. Primary concern
across eastern SD is whether or not the warmer low to mid-level
temperatures inhibit the development of mature updrafts.
One other scenario that seems plausible is for storms on southern
periphery the ongoing cluster to become increasingly surface based
as they move eastward/northeastward with time. Given current trends
and recent guidance, this would most likely occur along the eastern
ND/SD border after 20Z. As previously mentioned, hail is possible
within this cluster throughout the day, but the transition to a more surface-based character could introduce the threat for stronger
gusts as well.
A strengthening low-level jet coupled with persistent mid-level
westerlies support the potential for upscale growth in a
east-southeastward progressing MCS. Damaging gusts will be possible
with this MCS, particularly over SD, but increasing low-level
stability should result in a gradually diminishing severe potential
with eastward/southeastward extend into northeast NE, northwest IA,
and southwest MN.
..Mosier/Bentley.. 08/05/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Fri Aug 8 08:49:40 2025
ACUS01 KWNS 081250
SWODY1
SPC AC 081248
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Fri Aug 08 2025
Valid 081300Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE EASTERN DAKOTAS AND UPPER MISSISSIPPI VALLEY...
...SUMMARY...
Scattered severe thunderstorms are possible later today and tonight
across parts of the northern Plains and Upper Midwest. Scattered
damaging winds, large hail, and a couple tornadoes are possible.
...Northern Plains into the Upper Mississippi Valley...
An extensive MCS which produced numerous severe wind gusts across ND
earlier this morning has recently weakened across northern MN. While
occasional strong to locally damaging gusts may still occur in the
short term, this convection should continue weakening through the
rest of the morning as it moves into a less favorable thermodynamic environment. In the wake of this activity, an upper trough/low will
continue advancing eastward across the northern Rockies/Plains
towards the Upper Midwest through the period. At the surface, a weak
low over central SD this morning should develop northeastward to
northern MN by this evening, while a trailing cold front advances
southward across the northern/central High Plains.
Outflow from the morning convection may act as a pseudo warm front
and focus for renewed intense thunderstorm development later today
across parts of central/northern MN. The southern extent and
location of this boundary by this evening remains somewhat
uncertain. Even so, a rather moist and strongly to extremely
unstable airmass will be present east of the cold front and south of
the outflow boundary by late this afternoon across the upper MS
Valley. It still appears probable that additional surface-based
convection may develop by late afternoon/early evening across
eastern ND/northwest MN and vicinity as large-scale ascent preceding
the upper trough/low overspreads the warm sector.
While stronger flow aloft may tend to lag the surface cold front to
some extent, there should still be sufficient deep-layer shear to
support organized updrafts, including supercells with some large
hail threat. Given a large degree of boundary-parallel flow aloft, a
quick linear transition should occur this evening, with a greater
threat for severe/damaging winds. A narrow window for a couple of
tornadoes may exist across parts of MN, mainly this evening
along/near the residual outflow boundary where effective SRH may
become locally enhanced with a gradual strengthening of a southerly
low-level jet. Otherwise, the threat for damaging winds may continue
through tonight across parts of the upper MS Valley so long as any
MCS that develops can remain surface based. Given the potential
effects of the ongoing morning convection, confidence in a corridor
of more concentrated wind potential remains too low to include
greater severe probabilities with this update.
...High Plains...
Thunderstorms are ongoing this morning along/north of a cold front
in the western Dakotas. This activity may pose an isolated hail
threat given ample MUCAPE and strong deep-layer shear. The potential
for additional thunderstorms this afternoon/evening across the
central High Plains either along or behind the front in a low-level
upslope flow regime remains unclear. A conditional risk for
supercells with associated large hail threat is still apparent, but
overall coverage of intense convection may remain quite isolated.
Farther south across the southern High Plains, high-based convection
is expected to develop this afternoon within a hot and well-mixed
boundary layer. Deep-layer flow and related shear will generally
remain weak, but outflow-driven clusters may still be capable of
localized severe gusts.
...Northern Lower Michigan...
Similar to yesterday, isolated strong to severe thunderstorms may
develop this afternoon and evening across parts of northern Lower MI
and vicinity, along the northeast periphery of the substantial
reservoir of instability over the central Plains and Midwest. Modest northwesterly flow aloft will provide sufficient shear for some
updraft organization, with a threat for occasional hail and damaging winds.
..Gleason/Leitman.. 08/08/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Sun Aug 10 08:58:21 2025
ACUS01 KWNS 101236
SWODY1
SPC AC 101234
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0734 AM CDT Sun Aug 10 2025
Valid 101300Z - 111200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL/SOUTHERN PLAINS...
...SUMMARY...
Scattered severe thunderstorms are possible across parts of the central/southern Plains today and tonight, with large hail and
damaging winds the main threats. Strong to severe thunderstorms may
also occur from parts of the Midwest to the upper Great Lakes.
...Eastern Kansas/Missouri/Iowa to the Upper Great Lakes...
Loosely organized convection is ongoing this morning across parts of
eastern IA, aided by modest low-level warm advection and a MCV.
While this activity has generally remained sub-severe for the past
few hours, there is some potential for gradual re-intensification
through the afternoon as the MCV tracks northeastward across parts
of the Upper Midwest. While cloud cover is noted downstream per
early-morning visible satellite imagery, filtered daytime heating
should encourage the development of weak to locally moderate
instability by early to mid afternoon over portions of WI and
vicinity ahead of a weak front. It remains unclear whether a bowing
cluster will be able to form later today, but isolated damaging
winds may occur if it develops and can persist.
Farther south across eastern KS into MO, ongoing thunderstorms are
occurring generally to the north of a convectively reinforced
outflow boundary/front. While this elevated activity could pose an
isolated hail/wind threat this morning, it is generally forecast to
diminish by late morning as a southwesterly low-level jet gradually
weakens. However, additional thunderstorm development may occur this afternoon/evening along and south of the outflow boundary in MO as
daytime heating of a rather moist low-level airmass supports
moderate to strong instability. Deep-layer shear will remain weak
across this area, but occasional severe/damaging gusts could still
occur given the large degree of buoyancy forecast.
...Central/Southern Plains...
Extensive convective overturning yesterday/early this morning should
result in a less unstable post-frontal airmass across the
central/southern High Plains compared to Saturday. Even so, steep
mid-level lapse rates emanating from the Southwest should once again
overspread a modestly moist low-level airmass this afternoon. This
will foster the development of weak to moderate instability in
tandem with daytime heating. Thunderstorms will likely develop over
the higher terrain/CO Front Range by early afternoon as a weak
mid-level shortwave trough presently over eastern UT/western CO
moves eastward. Sufficient deep-layer shear for organized updrafts
is forecast, including the potential for a few supercells with
associated threat for mainly large hail, and perhaps a tornado.
With time, clustering should occur over the central/southern High
Plains along and perhaps a bit north of the convectively reinforced front/outflow boundary. Ample MUCAPE, steepened lapse rates aloft,
and a modest southerly low-level jet should support some threat for
severe gusts with one or more clusters that may spread eastward this
evening and overnight. Have expanded the Slight Risk eastward across
parts of western/central KS, the adjacent OK/TX Panhandles, and
northwest OK based on a consensus of recent model guidance showing
this potential.
..Gleason/Leitman.. 08/10/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Sun Aug 10 17:26:45 2025
ACUS01 KWNS 101957
SWODY1
SPC AC 101956
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Sun Aug 10 2025
Valid 102000Z - 111200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE CENTRAL AND SOUTHERN PLAINS...
...SUMMARY...
Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and
damaging winds the main threats.
...20z Update Front Range...
Initial thunderstorms should continue to develop over the higher
terrain of eastern CO and the Front Range as a broad upper trough
shifts eastward and low-level upslope flow continues this afternoon.
1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will
support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale
growth results in an MCS tonight. Damaging gusts are possible into
parts of the southern Plains. Have expanded the Slight Risk farther
north/east where development is possible closer to the WY/CO border.
...Mid Mississippi Valley...
Diurnal heating ahead of the weak cold front over the Midwest will
continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools
deepen. While vertical shear will not be strong, (generally less
than 20 kt) an occasional damaging gust remains possible over parts
of IL, MO and WI. Have expanded the Marginal risk eastward to cover
the low-end risk. Otherwise, see the prior outlook for additional info.
..Lyons.. 08/10/2025
.PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/
...CO/KS...
Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead
of this trough will aid in the development of scattered
thunderstorms along the foothills of central CO by early afternoon,
with storms spreading eastward through the afternoon/evening. Ample
low-level moisture and CAPE are present over eastern CO/western KS
to promote a few intense cells, with favorable westerly flow aloft
for supercell structures. Large hail is the main concern, with an
increasing risk of damaging winds with eastward extent this evening.
A tornado or two is possible as storms interact with a remnant
outflow boundary that extends across the TX Panhandle and northwest OK.
...MO/IL/WI...
A corridor of strong heating will encourage scattered thunderstorm
development this afternoon from southern MO into central/northeast
IL. Weak winds aloft and considerable mid-level moisture will limit
overall downdraft potential. Nevertheless, gusty/damaging winds
could occur with the strongest cells.
...Southeast AZ...
Similar to yesterday, scattered high-based afternoon/evening
thunderstorm development is expected over southeast AZ in a
hot/unstable environment. The strongest cells may produce locally
damaging wind gusts.
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Wed Aug 13 08:03:33 2025
ACUS01 KWNS 131239
SWODY1
SPC AC 131238
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0738 AM CDT Wed Aug 13 2025
Valid 131300Z - 141200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA...
...SUMMARY...
Scattered severe wind gusts and isolated large hail may occur across
parts of the northern/central Plains this evening and overnight.
Thunderstorms across portions of the Northeast and Mid-Atlantic may
produce occasional damaging winds this afternoon.
...Northern/Central Plains...
The primary upper trough will remain over western/central Canada
today, with quasi-zonal westerly mid-level flow continuing over much
of the northern Rockies/Plains through the period. A
subtle/low-amplitude shortwave trough over parts of ID/western MT
this morning associated with ongoing weak convection is forecast to
advance eastward towards eastern MT/WY and the western Dakotas by
early this evening. Gradually warming low/mid-level temperatures and
a stout cap will likely hinder surface-based convective development
across much of the northern/central Plains until mid to late
afternoon at the earliest. Still, the modest large-scale ascent
associated with the approaching shortwave trough may be sufficient
in tandem with robust daytime heating and localized orographic
effects near the Black Hills to initiate thunderstorms.
Modest low-level moisture will continue to stream northward today
along/east of a surface lee trough. Initially high-based convection
across the northern/central High Plains could pose an isolated
threat for mainly severe gusts as it continues eastwards towards
greater low-level moisture and MLCAPE. The best potential for a more
focused corridor of severe winds and isolated large hail still
appears generally along/east-southeast of the Black Hills towards
central SD and perhaps north-central NE this evening into the early
overnight hours. Here, moderate instability and deep-layer shear
should overlap with a very well-mixed boundary layer, supporting a
severe wind threat with any cluster that can become established amid
a gradually strengthening low-level jet. Some uncertainty still
remains regarding this potential, however, as low/mid-level
temperatures (around 850-700 mb) are forecast to remain quite warm.
...Northeast/Mid-Atlantic...
The Northeast and portions of the Mid-Atlantic will experience the
glancing influence of upper troughing advancing eastward over
Ontario/Quebec today. A moist low-level airmass is already in place
ahead of a weak surface front extending southwestward from the Great
Lakes into the Midwest. Although lapse rates aloft will remain poor
through the afternoon, diurnal heating ahead of ongoing showers and thunderstorms this morning should promote weak to locally moderate
instability from New England to parts of the Mid-Atlantic. Generally
modest mid-level flow (around 15-25 kt at 500 mb) should tend to
limit deep-layer shear given weak winds at low levels. Even so,
loosely organized clusters may still pose some threat for isolated
damaging winds this afternoon and early evening as convection
spreads eastward amid a boundary layer characterized by steepened
low-level lapse rates.
..Gleason/Leitman.. 08/13/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Thu Aug 14 08:52:52 2025
ACUS01 KWNS 141236
SWODY1
SPC AC 141234
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0734 AM CDT Thu Aug 14 2025
Valid 141300Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA...
...SUMMARY...
Thunderstorms capable of producing large hail and severe wind gusts
may occur this afternoon into tonight across parts of the
northern/central Plains and upper Mississippi Valley.
...Northern/Central Plains into the Upper Mississippi Valley...
Ongoing elevated thunderstorms across parts of eastern SD this
morning are occurring in association with a low-amplitude shortwave
trough and related low-level warm advection. This activity has
remained sub-severe through much of the early morning hours, but it
could still pose an isolated hail threat in the short term given
weak MUCAPE and sufficient deep-layer shear. It remains unclear
whether additional thunderstorm development will occur later this
afternoon across parts of southern MN and vicinity as the shortwave
trough continues eastward across the upper MS Valley. The airmass
across this area will gradually destabilize through the day, but
capping may tend to inhibit additional development. Still, a
conditional threat for isolated severe hail/wind exists if robust
thunderstorms can initiate, so have maintained the Marginal Risk
across southern MN for this possibility.
Thunderstorms across southern Manitoba this morning are expected to
generally remain along/north of the international border as they
continue eastward into western Ontario. A fairly strong
mid/upper-level trough will progress eastward today across Saskatchewan/Manitoba, with the southern fringe of this perturbation
glancing the northern Plains later today. Enhanced westerly
mid-level flow will overspread ND and northern MN late this
afternoon though tonight, while a surface cold front advances east-southeastward across the northern Plains through the period.
Low-level moisture will continue to stream northward ahead of the
front, with evapotranspiration also aiding surface dewpoints
potentially reaching into the upper 60s to perhaps low 70s by early
evening. Ample daytime heating and steep lapse rates aloft will aid
in the development of at least 2500-3500 J/kg of MLCAPE by late afternoon.
The primary uncertainty regarding convective development along the
front is a capped 850-700 mb layer and weak forcing with southward
extent across the northern Plains, as the primary upper trough will
remain across Canada through the period. Even so, low-level
convergence along the front may become sufficient for cells to
initiate by early evening, mainly across parts of eastern ND into
northwest MN where MLCIN should be weakest. Any convection which can
be sustained could pose a threat for large to isolated very large
hail given a favorable thermodynamic and kinematic environment. Some
potential for upscale growth into clusters along the front remains
apparent this evening into the early overnight hours, with greater
severe wind threat. However, inhibition will quickly increase with
eastward extent across MN as nocturnal cooling of the boundary layer
occurs; so, the severe wind threat remains uncertain.
Finally, scattered high-based thunderstorms should occur this
afternoon and evening farther south across parts of the central High
Plains. As this convection spreads eastward and encounters greater
instability along/east of a surface lee trough, it may become
capable of producing isolated severe gusts and perhaps marginally
severe hail. The lack of stronger forcing aloft and modest
deep-layer shear should temper the overall severe threat with
southward extent.
..Gleason/Leitman.. 08/14/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Mon Aug 18 09:27:24 2025
ACUS01 KWNS 181236
SWODY1
SPC AC 181235
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0735 AM CDT Mon Aug 18 2025
Valid 181300Z - 191200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL/NORTHERN PLAINS...AND OVER PARTS OF THE MIDWEST....
...SUMMARY...
Strong to severe storms capable of damaging winds are possible in
parts of the Midwest today. Widely scattered storms with large hail
and severe winds are possible in parts of the central/northern
Plains through tonight.
...IA/WI/IL...
A long-lived MCS continues to track eastward across central IA this
morning. Visible satellite imagery shows the potential for
considerable daytime heating ahead of this activity across parts of
eastern IA/southern WI/northern IL, where temperatures will warm
into the 90s. Ample low-level moisture will yield afternoon MLCAPE
values around 3000 J/kg, along with sufficient westerly flow aloft
for some convective organization. It is unclear whether current
activity will intensify, or new storms will form later today.
Regardless, this region will see the potential for strong/severe
storms capable of damaging wind gusts. A tornado or two is also
possible, given the backed low-level winds and east-west baroclinic
zone along the WI/IL border. Have added a SLGT risk for this
scenario.
...Northeast CO into SD/NE/KS...
Strong heating and ample low/mid level moisture will promote the
development of scattered thunderstorms by mid-afternoon over the
foothills and plains of central/eastern CO. Other more isolated
storms are expected farther north across western NE into the Black
Hills region. All of these storms will be relatively high-based,
posing a risk of damaging wind gusts. Sufficient westerly flow will
also aid in a few transient supercells capable of large hail. These
storms may persist into the evening, tracking into central NE before
weakening.
...MO/AR...
Clear skies are evident this morning across central/southern MO and
much of AR. Hot and humid conditions will ensue with temperatures
reaching the upper 90s. Most CAM solutions suggest widely scattered
afternoon thunderstorm development in this environment of steep
low-level lapse rates and 1500-2000 J/kg of MLCAPE. The strongest
storms will be capable of locally damaging wind gusts.
..Hart/Dean.. 08/18/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Mon Aug 18 19:04:21 2025
ACUS01 KWNS 182000
SWODY1
SPC AC 181959
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0259 PM CDT Mon Aug 18 2025
Valid 182000Z - 191200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
NORTHERN ILLINOIS AND PARTS OF THE CENTRAL AND NORTHERN PLAINS...
...SUMMARY...
Strong to severe storms capable of damaging winds are possible in
parts of the Midwest today. Widely scattered storms with large hail
and severe winds are possible in parts of the central/northern
Plains through tonight.
...20Z Update...
The primary change to the current Day 1 Outlook was to trim severe probabilities across portions of southern Wisconsin, where the
passage of an MCS has resulted in low-level stabilization.
Otherwise, only minor changes was made to severe/thunder
probabilities to reflect the latest guidance and observations.
..Squitieri.. 08/18/2025
.PREV DISCUSSION... /ISSUED 1129 AM CDT Mon Aug 18 2025/
...Mid MS Valley...
Extensive outflow from last night's MCS currently extends from
extreme southwest WI southwestward through eastern IA and
north-central MO into eastern KS. This outflow has been moving
quickly eastward/southeastward this morning, and this trend is
expected to continue, although some slowing of its progression speed
is possible over time. The downstream airmass across from southern
WI and IL is characterized by dewpoints in the low to mid 70s.
Mid-level lapse rates are generally poor across the region, but
heating of this very moist airmass will still result in strong to
very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon.
Strong to severe storms are possible along this outflow as it
impinges on this moist and buoyant airmass. Current trends suggest
the greatest severe potential will exist this afternoon across
southern WI and northern IL, where slightly stronger mid-level flow,
backed surface winds, and an east-west baroclinic zone exists.
Recently issued MCD 1983 addresses the short-term severe potential
for this area.
...Central High Plains into the northern/central Plains...
Strong heating and ample low/mid level moisture will promote the
development of scattered thunderstorms by mid-afternoon over the
foothills and plains of central/eastern CO. Additional isolated
storms are possible farther north across western NE into the Black
Hills region. Much of this area is within a corridor of modest
mid-level flow on the northern periphery of the upper ridging
covering the southern CONUS. Resulting modest shear may be enough
for hail production with the initial development before these
high-based storms trend towards outflow-dominant structures with
time. These storms may persist into the evening, with an attendant
threat for strong to severe gusts progressing into central NE before weakening.
...MO/AR...
Clear skies and strong diurnal heating are expected across
central/southern MO and much of AR. Temperatures in the upper 90s
are expected, with dewpoints remaining in the mid 60s despite strong
mixing. These hot and humid conditions will result in strong
buoyancy this afternoon, with most guidance suggesting MLCAPE around
2000 J/kg. Shear will be weak, yielding mostly disorganized
multicells, but the strongest storms will be capable of locally
damaging wind gusts.
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Thu Aug 28 09:02:04 2025
ACUS01 KWNS 281251
SWODY1
SPC AC 281249
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0749 AM CDT Thu Aug 28 2025
Valid 281300Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST
OKLAHOMA AND ARKLATEX...
...SUMMARY...
Strong thunderstorms, with an isolated hail and severe wind threat,
are possible across parts of southern Oklahoma and northern Texas to
the Arklatex this afternoon and evening. Isolated severe
thunderstorms will also be possible across eastern Colorado and the
adjacent High Plains.
...Southern Oklahoma/North Texas to ArkLaTex...
Showers/thunderstorms are prevalent this morning across
northern/eastern Oklahoma into the Ozarks to the north-northeast of
a warm front. Within a belt of moderately strong northwesterly flow
aloft, a shortwave trough will continue to dig southeastward from
the south-central Plains toward the Ozarks by this evening. Related
dynamical response and the early day convection will shunt the front
southward later today, with ample heating/moderate destabilization
on the southwest flank of this boundary.
While mid-level temperatures are seasonally warm (-4C at 500 mb),
and lapse rates are not that steep, severe hail and damaging wind
gusts can be expected with the more robust convection as general intensification occurs by mid/late afternoon. A few initial
supercells may occur, and some tornado risk could also exist with
convection immediately along the boundary and east of the weak
surface front. Clustering/upscale-quasi-linear growth should occur
by early evening as storms progress southeastward and continue to
pose a damaging wind risk for a time this evening.
...Eastern Colorado and adjacent High Plains...
The large-scale pattern is not expected to change appreciably as
upper ridging will hold across the southern/central Rockies. While
mid-level flow is not that strong across Colorado, low-level upslope
flow is expected to contribute to scattered thunderstorm development
as boundary layer heats later this afternoon. This activity will
spread southeastward with an attendant risk for isolated severe hail
and gusty winds.
..Guyer/Kerr.. 08/28/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Fri Sep 5 10:57:40 2025
ACUS01 KWNS 051211
SWODY1
SPC AC 051209
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0709 AM CDT Fri Sep 05 2025
Valid 051300Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE TENNESSEE VALLEY AND UPPER OHIO VALLEY...
...SUMMARY...
Scattered damaging winds, isolated severe hail, and a brief tornado
or two are possible from the Upper Ohio to Tennessee Valleys during
the late afternoon and evening.
...Upper OH to TN Valleys...
Water-vapor imagery shows a large gyre centered over Ontario and
cyclonic flow over much of eastern North America. A series of
mid-level disturbances/speed maxima will rotate through its base
during the Day-1 period, and there are two lead impulses over the
St. Lawrence Seaway and the Upper Great Lakes this morning. A
weaker impulse associated with convection early this morning over KS
will rapidly move east into the northern part of the OH Valley
through this evening and immediately ahead of a more notable
shortwave trough moving southeast from the Dakotas into the Great Lakes.
A cold front oriented mostly north-south over the Great Lakes from a
surface low will push east during the day, while the trailing
southern portion of the boundary that is west-east oriented,
gradually pushes south and eventually overtakes a residual frontal segment.
Heating ahead of the aforementioned low-amplitude impulse and
strengthening low-level convergence along the boundary will likely
yield scattered to numerous showers/thunderstorms developing in the
late afternoon to early evening. Much of the stronger mid-level
flow will remain spatially displaced from the warm sector in the
post-frontal airmass except over the Upper OH Valley. Moderate
buoyancy will favor strong to severe multicells and some supercells
(where shear is stronger). Isolated severe gusts (55-70 mph) seem
probable which will result in scattered wind damage accompanying the
stronger thunderstorm cores and line segments. Models differ on the
character of mixing and hodograph size over the southeast OH/WV
portion of the Slight Risk, but low-tornado potential may be
greatest here compared to farther south/southwest over the TN
Valley. The severe threat will diminish towards late evening given
the extensive overturning and lack of stronger low-level flow/shear
to sustain the threat overnight.
...North TX to Mid-South...
An elongated mid-level thermal trough, characterized by 500-mb
temperatures of -10 to -12 C, will extend into north TX, well to the
south of a persistent vertically stacked cyclone over northern
Ontario. A copious amount of high cloud cover will tend to result
in high-level lapse rates becoming weaker during the period. Model
data implies a messy storm mode as isolated to locally scattered
storm coverage ensues during the late afternoon/evening. An
isolated wind/hail risk may accompany the stronger storms.
..Smith/Broyles.. 09/05/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Sat Sep 6 09:45:25 2025
ACUS01 KWNS 061230
SWODY1
SPC AC 061229
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0729 AM CDT Sat Sep 06 2025
Valid 061300Z - 071200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN MID-ATLANTIC REGION INTO NEW ENGLAND...
...SUMMARY...
Scattered severe thunderstorms are possible from eastern
Pennsylvania and New Jersey into New England this afternoon. The
primary hazards will be strong to severe gusts capable of wind
damage and a tornado or two.
...Northeast...
Water-vapor imagery this morning shows a potent mid-level shortwave
trough moving east-northeast across Lower MI and embedded within a
larger scale cyclonic flow field over eastern North America. This
mid-level disturbance will move into southeast Quebec by this
evening. A weak frontal wave is forecast to evolve near the
NY/MA/VT border by early afternoon as a cold front sharpens and
begins to push towards the coast. A relatively moist airmass is
evident in surface observations this morning with dewpoints in the
lower 70s along the southern New England coast with mid to upper 60s
farther inland.
Despite some low cloud cover, sufficient heating will promote
moderate destabilization by early afternoon. Convection will likely
focus along the wind shift/cold front with scattered to numerous
storms eventually developing by mid-late afternoon. Model guidance
shows 35-40 kt southwesterly 700-mb flow and forecast soundings show
hodographs enlarging in the vicinity of the weak low as it migrates north-northeast across portions of southern New England into
southern ME. Several supercells are possible and have introduced
5-percent tornado probabilities this outlook to highlight where the
greatest low-level mesocyclone threat (i.e., possibility for a
tornado or two) is forecast. Otherwise, strong to severe gusts
capable of wind damage are expected from both supercells and the
more organized/intense cores and line segments. As the disturbance
becomes displaced from the region by early evening and with the loss
of heating, the severe risk will likely diminish.
...Mid-Atlantic states into the Carolinas/GA...
Southern extension of stronger flow will gradually taper with south
extent from the Mid-Atlantic states into the Carolinas. However,
sufficient destabilization of a seasonably moist airmass will favor
widely scattered to scattered thunderstorms evolving into a few
bands of thunderstorms this afternoon. The primary risk with the
more intense thunderstorms will be strong to locally severe gusts
capable of wind damage. This activity will likely weaken by the
early evening.
..Smith/Broyles.. 09/06/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Mon Sep 8 08:01:32 2025
ACUS01 KWNS 081221
SWODY1
SPC AC 081219
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0719 AM CDT Mon Sep 08 2025
Valid 081300Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE CENTRAL AND SOUTHERN HIGH PLAINS...
...SUMMARY...
Isolated large to very large hail and severe gusts are forecast over
portions of southwestern Kansas, northwest Oklahoma, and the Texas
Panhandle late this afternoon into the evening.
...Central/Southern High Plains...
Morning water-vapor imagery shows a mid-level shortwave trough
moving east-southeast across the central High Plains. Scattered showers/thunderstorms are ongoing from northern KS into the
northeast TX Panhandle associated with low-level warm-air advection.
This convection will likely remain weak and slowly shift
east-southeast before largely diminishing 18-21z. As the
aforementioned disturbance moves into central KS by late afternoon,
a differential heating zone arcing northward in wake of the
convection will intersect with a moisture plume extending northward
from west TX into the TX/OK/KS border region.
Heating will contribute to a moderate to very unstable airmass
(2000-3000 J/kg MLCAPE) from the TX Panhandle into southwest KS.
Weak low-level convergence should prove instrumental in convective
initiation late this afternoon into the early evening. Isolated to
scattered thunderstorms are probable with the locally highest risk
for severe in the northeast TX Panhandle into adjacent parts of
northwest OK and southwest KS. Model forecast hodographs are
elongated, which will favor supercells and hail growth given the
magnitude of buoyancy. Large to very large hail (1 to 3 inches in
diameter) is possible with the stronger storms. A brief tornado
cannot be ruled out during the early evening transition when
low-level shear increases. Severe gusts may also accompany the
stronger cores through much of the evening before this activity
diminishes 03-05z.
...Upper MS Valley Vicinity...
Northern stream short-wave trough is forecast to dig southeast
across southern MB/ND into the upper Red River region by early
evening. This should aid in the development and intensification of
a southwesterly LLJ forecast to overspread the Upper Midwest during
the period. Large-scale forcing favors elevated convection along
the nose of this jet, especially across the Arrowhead of MN/Lake
Superior. Relatively steeper lapse rates may permit a few robust
updrafts to evolve shortly after peak heating with an attendant risk
for isolated marginally severe hail.
...Central OR...
A mid- to upper-level shortwave trough located to the west of the
northern CA coast will move east-northeast into southwest OR by late
tonight. Heating coupled with large-scale ascent associated with
the disturbance will favor scattered thunderstorms developing this
afternoon near and east of the Cascades. Forecast soundings show
500-mb temperatures around -15 deg C and weak buoyancy. A couple of
the stronger updrafts may yield a near-severe hail threat (0.50-1.00
inch in diameter) for a few hours.
..Smith/Broyles.. 09/08/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Thu Sep 11 08:48:34 2025
ACUS01 KWNS 111206
SWODY1
SPC AC 111205
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0705 AM CDT Thu Sep 11 2025
Valid 111300Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN
MONTANA INTO WESTERN NORTH DAKOTA...
...SUMMARY...
Scattered severe thunderstorms are possible over eastern Montana
into western North Dakota late this afternoon through the evening.
The primary hazards are severe gusts and large hail.
...Synopsis...
Water-vapor imagery shows a large cyclone over the West with a
downstream ridge over the Great Plains, and a trough centered over
the Lower Great Lakes. Southwesterly mid to high-level flow extends
from the base of the larger-scale western U.S. trough northeastward
through the Great Basin and into the northern Great Plains. A
mid-level disturbance implied in morning water-vapor imagery over
western WY, is forecast to move northeast into eastern MT/western ND
towards this evening.
In the low levels, a plume of seasonably rich moisture will protrude
northward from the central Plains into the Dakotas and eastern MT.
A lee trough will extend southward from a surface low over the
northern High Plains.
...Rockies into the northern Plains...
An ongoing cluster of weak thunderstorms associated with warm-air
advection near the ND/Manitoba border will continue to move
east-northeastward into southern Canada ahead of a pair of MCVs over
western ND/eastern MT. Diurnal heating over the higher terrain from
near the Four Corners northward into southern MT will favor
scattered thunderstorms developing during the midday into the early
afternoon. Storm coverage will probably increase further over the
central Rockies during the afternoon, with the stronger storms
capable of an isolated hail/wind threat. As the airmass
destabilizes over the plains, particularly across eastern MT within
the moist plume primarily north of the surface low, isolated to
scattered storms are forecast by mid to late afternoon. This
initial activity will probably develop near the MT/WY border with
upscale growth into a cluster possible during the evening.
Deep-layer shear supporting organized storm modes coupled with steep
lapse rates, will combine to aid in several stronger storms capable
of a hail/wind threat. The wind threat will probably continue into
ND during the evening within the terminus region of a 35-40 kt
southerly LLJ. A gradual transition to increasingly elevated
convection is expected late as convective inhibition increases and
the overall severe risk lessens.
..Smith/Broyles.. 09/11/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Fri Sep 12 13:15:56 2025
ACUS01 KWNS 121641
SWODY1
SPC AC 121639
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1139 AM CDT Fri Sep 12 2025
Valid 121630Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR
CORNERS AREA AND NORTHERN HIGH PLAINS...
...SUMMARY...
Isolated severe storms will be possible today across the Four
Corners area and central Rockies, with an increasing risk for severe
storms into late afternoon and tonight across the northern Plains.
...Four Corners Region/central Rockies...
Ahead of the prominent upper trough centered over the Great Basin
and Lower Colorado River Valley, a lead mid-level impulse and
related height falls and a strengthening of cyclonic flow aloft will
influence the region. Cooling mid-level temperatures and a modestly
warming boundary layer will further steepen lapse rates diurnally,
with strong to severe storms expected to further develop into the
afternoon. Relatively strong flow aloft with 40+ kt effective shear
will support some supercell structures, with a related enhanced
potential for severe hail, aside from locally gusty thunderstorm
winds. More severe-favorable ingredients and a somewhat higher
potential for severe storms appears to exist across the Four Corners
vicinity including northwest New Mexico across western Colorado
through the afternoon.
...Northern Plains including Eastern Montana/western Dakotas...
Thunderstorm development/intensification is expected by late
afternoon, initially on an isolated basis across central/eastern
portions of Montana and Wyoming. Cooling mid-level temperatures and
surface dew points in the 50s F will contribute to 500-1000 J/kg
MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be
favorable for isolated storms with hail potential. Storm coverage
should steadily increase into the evening toward the western
Dakotas, aided by the arriving influence of greater forcing for
ascent as located over the central Rockies early today. Hail
potential will become more common this evening, with localized
severe wind potential also modestly increasing. Strong/locally
severe storms will potentially persist overnight across the western
and central Dakotas.
...Northern/central Minnesota to northwest Wisconsin...
Very isolated elevated severe storms, with hail as the most probable
hazard, may continue east-southeastward today, semi-focused by
elevated moisture transport well to the north of a warm front.
..Guyer/Jirak.. 09/12/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Fri Sep 12 18:17:24 2025
ACUS01 KWNS 122002
SWODY1
SPC AC 122000
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Fri Sep 12 2025
Valid 122000Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR
CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS...
...SUMMARY...
Isolated severe storms remain possible this afternoon across the
Four Corners area and central Rockies, with an increasing risk for
severe storms into late afternoon and tonight across the northern Plains.
...Four Corners vicinity into the Southwest...
The Slight Risk has been expanded westward into parts of
southeast/east-central UT, where favorable deep-layer shear and
modest but sufficient instability remains in place this afternoon.
Occasional small supercells will continue to be possible, with a
threat of hail and localized strong/severe gusts. See MCD 2066 for
more details.
The Marginal Risk has been expanded slightly westward across
southeast AZ, based on trends on visible satellite. The 18Z TUS
depicted a favorable conditional environment for severe storms, with
moderate MLCAPE and deep-layer shear. While the threat should
generally remain rather isolated, a supercell or two will be
possible, with an attendant threat of hail and localized severe
gusts. See MCD 2065 for more information.
...Northern High Plains vicinity...
Only modest adjustments have been made to the Marginal Risk across
the northern High Plains vicinity, with no changes to the Slight
Risk. An isolated threat for hail and strong/severe gusts may
develop later this afternoon, with some increase in coverage of the
severe threat expected into this evening. See MCD 2067 and the
previous discussion below for more details.
...East-central MN into northwest WI...
Much of the Marginal Risk across MN and northwest WI has been
removed. An earlier cluster of storms has generally weakened this
afternoon across east-central MN, though modestly steep midlevel
lapse rates and relatively favorable effective shear could still
support a threat for small to near-severe hail and locally gusty
winds as these storms move into northwest WI. Additional elevated
convection may develop later tonight across the same general region,
but severe potential with the later storms appears limited at this time.
..Dean.. 09/12/2025
.PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/
...Four Corners Region/central Rockies...
Ahead of the prominent upper trough centered over the Great Basin
and Lower Colorado River Valley, a lead mid-level impulse and
related height falls and a strengthening of cyclonic flow aloft will
influence the region. Cooling mid-level temperatures and a modestly
warming boundary layer will further steepen lapse rates diurnally,
with strong to severe storms expected to further develop into the
afternoon. Relatively strong flow aloft with 40+ kt effective shear
will support some supercell structures, with a related enhanced
potential for severe hail, aside from locally gusty thunderstorm
winds. More severe-favorable ingredients and a somewhat higher
potential for severe storms appears to exist across the Four Corners
vicinity including northwest New Mexico across western Colorado
through the afternoon.
...Northern Plains including Eastern Montana/western Dakotas...
Thunderstorm development/intensification is expected by late
afternoon, initially on an isolated basis across central/eastern
portions of Montana and Wyoming. Cooling mid-level temperatures and
surface dew points in the 50s F will contribute to 500-1000 J/kg
MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be
favorable for isolated storms with hail potential. Storm coverage
should steadily increase into the evening toward the western
Dakotas, aided by the arriving influence of greater forcing for
ascent as located over the central Rockies early today. Hail
potential will become more common this evening, with localized
severe wind potential also modestly increasing. Strong/locally
severe storms will potentially persist overnight across the western
and central Dakotas.
...Northern/central Minnesota to northwest Wisconsin...
Very isolated elevated severe storms, with hail as the most probable
hazard, may continue east-southeastward today, semi-focused by
elevated moisture transport well to the north of a warm front.
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Sun Sep 14 10:12:10 2025
ACUS01 KWNS 141242
SWODY1
SPC AC 141240
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 AM CDT Sun Sep 14 2025
Valid 141300Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE NORTHERN AND CENTRAL GREAT PLAINS...
...SUMMARY...
Isolated severe thunderstorms are possible across a broad portion of
the Great Plains this afternoon to early evening. A more
concentrated threat for a couple tornadoes is evident over parts of
the Dakotas and for large hail along the Nebraska-Kansas border.
...Dakotas/Western Minnesota...
Within a meridional mid-level flow regime, a surface low is forecast
to lift north across the central Dakotas this afternoon/evening. A
low-level jet will strengthen across the eastern Dakotas towards
evening, while moist easterly surface flow will exist north of the
low. These processes will result in a relatively confined corridor
of enhanced SRH lifting north from north-central SD into central ND
later today. In the wake of ongoing precipitation this morning,
renewed thunderstorm development is expected this afternoon across
the Dakotas along a cold front as ascent with the consolidating and increasingly negatively-tilted upper trough intensifies. Although
the primary risks will be isolated strong/severe gusts and hail with
multicell or transient supercell structures, storms near the
aforementioned surface low/Slight Risk could plausibly acquire
sufficient low-level rotation resulting in some tornado potential.
Overall intensities should diminish later this evening.
...Central Great Plains...
In the wake of overnight storms, boundary-layer heating of a
seasonably moist boundary layer will contribute to moderate-strong
buoyancy east of a cold front this afternoon. Although stronger wind fields/greater shear will be displaced to the east, sufficient
overlap is expected, with the potential for both multicell and
supercell characteristics resulting in severe hail/wind potential. A
confined plume of steeper mid-level lapse rates (in excess of 7 deg
C/km) southeast of the consolidating trough will promote a more
concentrated risk for severe hail, centered near the NE/KS border
Slight Risk area.
...Southern High Plains...
Scattered thunderstorms are expected to develop this afternoon
within a moderate-strongly buoyant air mass amid modest westerly
cloud-bearing layer shear. Both multicell and brief supercell
structures are possible with a risk for isolated severe wind and
hail, however warmer mid-level temperatures south of the upper
trough should tend to temper overall coverage.
...Mid-South/Mid-MS Valley...
Ample buoyancy along and southwest of a warm front should aid in a
few strong gusts and small hail with scattered late afternoon
storms. Deep-layer shear will remain rather weak within the
mid-level ridge, suggesting a predominant pulse mode, supporting a
minimal threat for organized severe storms.
..Bunting/Broyles.. 09/14/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
-
From
Mike Powell@618:250/1 to
All on Tue Sep 16 10:04:01 2025
ACUS01 KWNS 161234
SWODY1
SPC AC 161233
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0733 AM CDT Tue Sep 16 2025
Valid 161300Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS FAR
NORTHEAST CO...WESTERN/CENTRAL NE...AND EXTREME NORTHWEST KS...
...SUMMARY...
Scattered severe thunderstorms are possible this afternoon into
early evening across a portion of the central Great Plains. Large
hail, severe gusts, and a tornado or two may occur.
...Synopsis...
Early morning satellite imagery shows a fairly amplified upper
pattern across CONUS, consisting of two ridge/trough pairs. The
westernmost pair features ridging that extends from just off the
central CA coast north through southern BC and a shortwave trough
that extends from central MT into northeast NV/northwest UT. The
eastern most pair features ridging from the southern Plains through
the Upper Great Lakes and a modest cyclone centered over central NC.
Despite this amplified upper pattern, flow is generally modest, with
the strongest flow extending through the base of the western
shortwave from northern UT into eastern WY.
The surface analysis reveals a relatively nondescript surface
pattern free of any sharp gradients or notable features, aside from
a weak low just off the northeast NC coast. Moderate moisture (i.e.
mid/upper 60s dewpoints) does extend from the southern Plains
through the Lower MO Valley into southern IA.
...Central High Plains into the Central Plains ...
The western shortwave trough mentioned in the synopsis is forecast
to progress slowly eastward throughout the day, evolving towards a
more closed mid/upper level circulation as it does. Eastern
periphery of ascent associated with this shortwave will impinge on
the western periphery of the better low-level moisture and buoyancy,
resulting in scattered to numerous thunderstorms from eastern WY/CO
into western NE/KS. The best buoyancy across the region will likely
reside from far northeast CO into central NE where low to mid 60s
dewpoints beneath steep mid-level lapse rates will support MLCAPE
around 2000-2500 J/kg. Low-level convergence along a weak cold front
is anticipated in this area as well. The resulting combination of
lift, instability, and modest shear (i.e. around 35 kt of effective
bulk shear) will support strong to severe storms. Large hail appears
to be the most prominent hazard, but some clustering could lead to a
few strong gusts as well. Presence of a surface low and potential
backed low-level flow will result in a low-probability tornado risk
as well.
...Eastern SD to northeast MN...
Steep lapse rates atop moderate low-level moisture will support
moderate to strong buoyancy along a weak front zone forecast to
extend from eastern SD into north-central MN this afternoon.
Low-level convergence along the front will be modest, with warm low
to mid-level temperatures (and resultant capping) likely keeping
storm coverage isolated. Mid-level flow will be modest across most
of the region, but the strong buoyancy could still result in an
isolated threat for severe hail and damaging winds with any storms
that develop. A relatively higher severe potential exists across
northeast NM, where stronger mid-level flow through southern
peripheral of a shortwave trough moving over far northwest Ontario
will be in place this evening.
...VA Tidewater and far northeast NC...
A weak cyclone east of the Outer Banks is progged to drift
northwestward today, reaching the NC/VA border area by this
afternoon. Low-level flow enhancement through its northwest
periphery will promote potential for strong to marginally severe
gusts with any sustained convection. However, the more buoyant air
is expected to remain offshore and displaced east of this stronger
low-level flow, thermodynamically limiting the spatial extent of any
severe threat. Meager surface-based instability may glance the coast
from later this morning through the afternoon before low-level wind
fields subside and the severe risk becomes negligible.
..Mosier/Bentley.. 09/16/2025
$$
--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)