Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0724 PM CDT Fri Oct 03 2025
Valid 040100Z - 041200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms remain possible across much of the Rockies
and Great Basin. Isolated storms are also expected across portions
of the Gulf Coast and upper Great Lakes region.
...01z Update...
High level diffluent flow has overspread much of the Great Basin
into the central Rockies early this evening, just ahead of a
pronounced upper Low located over western NV/southern CA. Despite
meager instability, isolated frontal convection should be common
ahead of the upper trough tonight. While some of this activity could
generate gusts at times, current expectations are that the severe
risk is too low to warrant probabilities.
Isolated thunderstorms are also possible tonight along the
central/western Gulf Coast and near the international border with
Canada from the upper Red River Valley into the U.P. of MI. This
activity is also expected to remain below severe levels.
..Darrow.. 10/04/2025
$$
610
ACUS02 KWNS 031652
SWODY2
SPC AC 031650
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1150 AM CDT Fri Oct 03 2025
Valid 041200Z - 051200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE CENTRAL ROCKIES INTO THE NORTHERN PLAINS...
...SUMMARY...
Isolated severe wind gusts/hail may accompany the stronger
thunderstorms across the central Rockies into the northern High
Plains tomorrow (Saturday).
...Synopsis...
Broad upper troughing will take place across the western and central
U.S., while upper riding perseveres over the eastern CONUS tomorrow
(Saturday). A pronounced embedded mid-level impulse will eject into
the northern Plains, supporting the deepening of a surface low over
SD by afternoon, with a second surface low likely developing over
western WY. Low-level moisture will advect northward ahead of the SD
surface low as a cold front approaches from the central/northern
High Plains. An unstable but capped airmass will characterize the
warm sector, with thunderstorm development most likely along and
behind the cold front by tomorrow evening. Given adequate vertical
wind shear, a few of these storms may be severe across the central
Rockies into the northern Plains.
...Central Rockies into the central High Plains...
Thunderstorms are expected to develop by afternoon in association
with the western (WY) surface low, atop a mixed boundary layer.
Instability will be marginal over the central Rockies toward the
central High Plains (e.g. less than 500 J/kg MLCAPE). However,
rapidly strengthening winds with height will support strong speed
shear. As such, multicells with an isolated severe wind/hail threat
will exist across the central Rockies into the central High Plains
during the afternoon hours.
...Northern High Plains...
By afternoon peak heating, ahead of the cold front, surface
temperatures will likely reach into the upper 80s F, amid low 60s F
dewpoints across the northern Plains. Across the warm sector,
1000-2500 J/kg MLCAPE is expected, with the higher values of MLCAPE
constrained to the eastern Dakotas and MN, where richer low-level
moisture will be. Deep-layer forcing for ascent, needed to support
thunderstorm development against appreciable MLCINH, will be
displaced to the west, closer to and behind the surface cold front.
As forcing gradually overspreads the northern Plains/cold front
during the evening, thunderstorms should develop along/immediately
behind the cold front. Given strong speed shear parallel to the
front, the stronger linear segments will be capable of isolated
severe gusts and perhaps an instance of hail Saturday evening and
overnight.
..Squitieri.. 10/03/2025
$$
340
ACUS03 KWNS 031911
SWODY3
SPC AC 031910
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0210 PM CDT Fri Oct 03 2025
Valid 051200Z - 061200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE CENTRAL PLAINS...
...SUMMARY...
Isolated severe thunderstorms are possible over portions of the
central Plains on Sunday.
...Synopsis...
A surface cold front will remain stationary across the Plains
states, as a pronounced mid-level impulse over the Upper MS Valley
ejects into Ontario, and broader upper troughing remains in place
over the central U.S. Modest low-level moisture will continue to
advect north-northwestward as lee troughing persist over the central
and southern Plains. By late afternoon, subtle lifting along the
cold front, along with peak diurnal heating, should support
scattered thunderstorm development over the central Plains. Adequate
buoyancy and shear will be in place to support an isolated severe
threat.
...Central Plains...
The stationary surface cold front will be positioned along a line
roughly from central NE to the western TX Panhandle somewhere in the
18-00Z time frame. By afternoon peak heating, surface temperatures
will exceed 80 F amid upper 50s to perhaps 60 F dewpoints, yielding
between 500-1000 J/kg MLCAPE. Given somewhat warm temperatures aloft
and meager moisture return, thunderstorm development will be
dependent on surface heating and any subtle convergence along the
cold front. Nonetheless, the latest 12Z 3-km NAM, ECMWF, and GFS
runs all depict convective initiation along the cold front from
south-central NE to the OK/TX Panhandles by Sunday evening. By this
time, a southeasterly LLJ will be in place, beneath 700-500 mb flow
that quickly veers to west-southwesterly, which will support
enlarged, curved hodographs. Despite poor buoyancy and weak forcing
for ascent, a few multicells or even a transient supercell or two
may develop, capable of an instance or two of marginally severe
hail/wind or a brief tornado.
..Squitieri.. 10/03/2025
$$
100
ACUS48 KWNS 030817
SWOD48
SPC AC 030816
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0316 AM CDT Fri Oct 03 2025
Valid 061200Z - 111200Z
...DISCUSSION...
A cold front is forecast to move east across much of the Midwest and
Northeast/Mid-Atlantic vicinity through Day 6/Wed. This could result
in increasing thunderstorm potential ahead of this feature given a
moist prefrontal boundary layer. Most guidance suggests instability
will be limited however, likely due to a combination of weak lapse
rates and areas of cloudiness/showers ahead of the front. Severe
thunderstorm potential appears low.
Further west, the ECMWF suite of guidance suggests an upper
shortwave trough may eject across the central Rockies into the
central Plains around Day 6 or 7/Wed or Thu, with some southerly
return flow bringing Gulf moisture northward ahead of this feature.
However, the GFS suite of guidance is delayed with this feature
until near/after Day 8/Fri. Thunderstorm could increase across parts
of the Plains late in the forecast period, but uncertainty/model
spread is quite large.
