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DAY2 2/5 Risk Area Posted
From
Mike Powell@618:250/1 to
All on Tue Sep 2 09:18:25 2025
ACUS02 KWNS 020601
SWODY2
SPC AC 020600
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Tue Sep 02 2025
Valid 031200Z - 041200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL INTO EASTERN KANSAS...
...SUMMARY...
A risk of severe storms exists for portions of the central Plains.
Severe wind and hail are the primary threats, and an instance or two
of 2+ inch diameter hail is also possible.
...Synopsis...
A mid-level trough will rapidly amplify across the MS Valley region
while upper ridging persists over the Interior West tomorrow
(Wednesday). The central U.S. will be located within a deep-layer
northwesterly flow regime. A surface cold front will surge southward
across the central Plains, acting as a low-level lifting source (via convergence) for seasonal low-level moisture over the region. At
least scattered strong thunderstorms are expected ahead of the cold
front during the afternoon. Given strong flow/shear and colder
temperatures aloft overspreading the pre-frontal airmass with the
passage of an embedded impulse, some of the storms are expected to
be severe.
...Central Plains...
As the surface cold front approaches central and eastern KS from the
north, surface temperatures may exceed 80 F amid mid to upper 60s F
dewpoints. With 7-8 C/km mid-level lapse rates overspreading this
airmass, MLCAPE may reach as high as 2500 J/kg in spots.
Kinematically speaking, veering low-level flow, overspread by strong northwesterlies will yield curved and elongated hodographs with
40-50 kts of effective bulk shear. The stronger storms are expected
to become supercells, accompanied by severe wind and hail. There are
some indications that a couple of stronger, sustained supercells may
develop across eastern KS during the late afternoon to early evening
hours. Given both the vertical shear profiles and colder
temperatures aloft, a couple instances of 2+ inch hail and perhaps a
tornado are possible.
..Squitieri.. 09/02/2025
$$
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From
Mike Powell@618:250/1 to
All on Sun Sep 21 09:00:48 2025
ACUS02 KWNS 210617
SWODY2
SPC AC 210616
Day 2 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0116 AM CDT Sun Sep 21 2025
Valid 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHWEST/SOUTH-CENTRAL KANSAS...WESTERN/CENTRAL OKLAHOMA...AND THE
EASTERN TEXAS/OKLAHOMA PANHANDLES...
...SUMMARY...
Scattered severe thunderstorms will be possible on Monday across
portions of the central and southern High Plains.
...Synopsis...
On Monday, a mid-level trough will move from the upper
Midwest/Missouri Valley to the Great Lakes/Ohio Valley during the
period. Farther west, a more complicated pattern will develop as a
ridge builds into the Pacific Northwest. As this ridge builds, a
mid-level jet streak will be shunted south across the central
Rockies. This will deepen a mid-level low with a closed circulation
likely developing across the central High Plains region by 12Z
Tuesday. In addition, a closed low will persist off the southern
California coast for much of the period. High pressure will be
present across much of the western CONUS with weak lee troughing
along the central and southern High Plains. The surface pattern will
be somewhat less defined farther east with a weak remnant front
likely through the Upper Midwest to the western Great Lakes. High
pressure will dominate areas east of the Appalachians.
...Central Plains...
Moderate to strong instability will develop by Monday afternoon in
the wake of a morning MCS across Oklahoma/Kansas. Forecast soundings
show a strongly capped airmass across Kansas/Oklahoma and given the
relatively weak forcing amid modest height falls, do not expect much thunderstorm development until after 00Z. After this time, the
mid-level trough will start to overspread the Plains with a
strengthening low-level jet potentially approaching 50 knots.
Cooling temperatures aloft and strong isentropic ascent should
result in thunderstorm development after sunset Monday evening. Seep
mid-level lapse rates and strengthening effective shear (40 to 50
knots) will support the potential for supercells with some hail
threat. As upscale growth continues, the severe wind threat should
increase and continue into the overnight period into portions of central/northern Oklahoma.
...NE/IA to Lake Michigan...
Diurnal thunderstorm development is possible along a diffuse frontal
zone from Nebraska to southern Wisconsin. Modest lapse rates and
moderate instability along this zone will support some multicells
capable of some hail or damaging wind gusts. However, mostly weak
deep-layer shear (20 knots) and weak upper forcing should keep the
overall threat along this zone relatively isolated.
...Tennessee Valley to the eastern Great Lakes...
A weak mid-level shortwave trough is forecast to move through the
Ohio Valley on Monday with moderate instability forecast ahead of
it. An uncapped airmass and some moderate upper-level support in a
broader zone of weak, but persistent isentropic ascent should
support scattered thunderstorm development. Lapse rates will be
poor, but modest effective shear amid 30 to 35 knots of mid-level
flow may support some organized multicells capable of damaging wind
gusts Monday afternoon/evening.
..Bentley.. 09/21/2025
$$
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From
Mike Powell@618:250/1 to
All on Mon Sep 22 09:18:51 2025
ACUS02 KWNS 220559
SWODY2
SPC AC 220557
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Mon Sep 22 2025
Valid 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
OKLAHOMA...FAR NORTHEAST TEXAS...AND MUCH OF ARKANSAS...
...SUMMARY...
Strong to severe storms are possible from the southern Plains to the
Tennessee Valley on Tuesday. Strongest thunderstorm activity is
expected across eastern Oklahoma into northeastern Texas and
Arkansas, where supercells capable of all severe hazards are
possible by afternoon.
...Synopsis...
A positively tilted mid-level trough will begin the period across
eastern Colorado and shift east through the day to the Missouri
Valley region by 12Z Wednesday. A 40 to 50 knot mid-level jet streak
associated with overnight convection Monday night across KS/OK will
shift east across MO/AR during the day Tuesday and gradually weaken.
In its wake, the primary mid-level jet streak will emerge across
Oklahoma and strengthen Tuesday night as it moves from Oklahoma into
Arkansas. A weak surface low is forecast to be across northwest
Oklahoma Tuesday morning. This surface low and its associated cold
front will drift slowly east through the day.
...Eastern Oklahoma into much of Arkansas and northeast Texas...
A large MCS will likely be ongoing Tuesday morning across eastern
Kansas, southwest Missouri, and northeast Oklahoma on the nose of a
40 to 50 knot low-level jet. As the low-level jet weakens during the
morning and storms move east of the greatest shear/instability,
expect the MCS to weaken. Some isolated damaging wind gusts may
persist across northern Arkansas/southern Missouri and into TN/KY,
but expect this activity to remain mostly sub-severe.
The primary severe weather concern will be Tuesday afternoon/evening
across eastern Oklahoma and western Arkansas. Strong instability is
forecast across this region in the wake of the morning MCS as cool
temperatures aloft overspread low to mid 70s dewpoints. RAP/NAM
forecast soundings show only modest heating is necessary to erode
inhibition. Therefore, expect additional thunderstorm development
during the afternoon along and ahead of the cold front as it moves
across Oklahoma. Storm motion orthogonal to the front should favor
movement along and perhaps off of the front and into the warm
sector. Therefore, all severe hazards will be possible across this
region in a favorable environment featuring strong instability,
moderate deep-layer shear, and elongating, cyclonically curved
hodographs.
A conditional, potentially more volatile tornado threat is possible
across eastern Oklahoma and western Arkansas if significant
destabilization can occur north of any outflow boundary left by
morning convection. 03Z RAP/00Z NAM forecast soundings near Fort
Smith capture this conditional environment well and would
potentially support strong tornadoes. However, this evolution is
highly dependent on the evolution of Day 1 convection across Kansas
and Oklahoma which still remains unclear. In addition, the time
window for this favorable environment would be narrow which also
adds conditionality to the risk. This scenario will be monitored
closely and a Level 3/Enhanced Risk may be justified in later
outlooks if this scenario appears more likely.
...Central Texas...
Moderate instability is forecast across central/northern Texas
Tuesday afternoon with eroding inhibition by mid-afternoon. Shear
will be relatively weak, but will increase during the
afternoon/evening as the mid-level jet streak drifts south. The most
favorable zone for thunderstorm development will be the triple point
where the cold front and dryline intersect across North Texas.
However, additional isolated storms may also develop along the
dryline and cold front. Isolated large hail and damaging wind gusts
will be the primary threat from these storms Tuesday
afternoon/evening.
...Tennessee Valley...
A weak warm front may be a focus for storm development Tuesday afternoon/evening across western/middle Tennessee as moderate
instability develops across the region. Deep-layer shear should
remain quite weak (less than 20 knots) as the primary mid-level jet
streak remains farther west. However, a few stronger storms capable
of damaging wind gusts may develop during the afternoon/evening.
..Bentley.. 09/22/2025
$$
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