Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
SPC AC 011948
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0148 PM CST Wed Dec 01 2021
Valid 012000Z - 021200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms remain possible into early evening across
parts of the Mid-Mississippi Valley into Kentucky and Tennessee.
...20z Update...
Elevated convection ahead of the fast-moving shortwave trough has
continued to produce frequent lightning despite meager buoyancy
across portions of the mid-Mississippi Valley. As the progressive
trough continues southeastward, broad ascent and strengthening
mid-level warm advection may continue to support isolated
thunderstorms through portions of Tennessee and southern Kentucky
into this evening. Forecast confidence remains low given most
regional model soundings and Hi-res guidance depict scant buoyancy
below 200 J/kg. However, current trends warrant the continuation of
general thunder probabilities downstream of the ongoing elevated
convection. Thunder probabilities were also removed behind the line
where increasing stability should limit thunder potential.
..Lyons/Grams.. 12/01/2021
.PREV DISCUSSION... /ISSUED 1009 AM CST Wed Dec 01 2021/
...Mid-MS Valley to KY/TN...
A flurry of lightning flashes occurred over the past few hours
across southeast MO and southern IL within an arc of elevated
convection in the forced ascent corridor ahead of a progressive
shortwave trough. Area 12Z RAOBs and recent AMDAR data near Memphis
and Nashville suggest buoyancy in this regime is scant and spatially
confined within a modestly steep mid-level lapse rate plume,
rendering above-average uncertainty in the longevity of the isolated
thunderstorm threat. CAM guidance that tended to more accurately
simulate the ongoing convection suggests an overall decrease this
afternoon as large-scale ascent appears to diminish slightly. Still,
potential for very isolated thunderstorms may persist farther east
in TN/KY through early evening before instability/buoyancy becomes
negligible.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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