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 271936
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0136 PM CST Sat Nov 27 2021
Valid 272000Z - 281200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorms are not expected across the contiguous United States
through early Sunday.
...20z update...
Widespread cloud cover and offshore flow will continue to limit the
potential for thunderstorm activity across south Texas to offshore
late this evening. The previous discussion remains valid with no
changes. See below for additional information.
..Lyons/Leitman.. 11/27/2021
.PREV DISCUSSION... /ISSUED 1021 AM CST Sat Nov 27 2021/
...Synopsis...
Within the southern stream of the mid-level westerlies, a weak upper
low over northern Mexico and West Texas will transition to an open
shortwave trough as it moves east and is absorbed by a larger
synoptic trough over the northeastern CONUS. At the surface, a cool
post-frontal airmass over central and southern Texas will undergo
minimal modification through the day, with widespread showers and
cloud cover limiting diurnal heating north of the remnant coastal
front. Regional observed and model soundings show generally weak
lapse rates, less than 6.5 C/km, through the column despite cooling
temperatures aloft. The net effect will be insufficient buoyancy
available for updrafts capable of lightning as the core of the
shortwave trough moves over south Texas this afternoon and evening.
A secondary cold front and weak cyclogenesis along the coastal front
will reinforce offshore flow as cold air ahead of strengthening
surface high pressure over the interior CONUS will scour remaining
moisture late tonight into early Sunday, precluding thunderstorm
development over the CONUS.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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