Dec 27, 2021 2000 UTC Day 1 Convective Outlook
Updated: Mon Dec 27 19:52:02 UTC 2021 (20211227 2000Z Day 1 shapefile | 20211227 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20211227 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Tornado Graphic
20211227 2000 UTC Day 1 Tornado Probabilities Graphic
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
20211227 2000 UTC Day 1 Damaging Wind Probabilities 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
20211227 2000 UTC Day 1 Large Hail Probabilities 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 271952

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0152 PM CST Mon Dec 27 2021

   Valid 272000Z - 281200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Thunderstorms are possible today over parts of the mid/upper Ohio
   Valley region, while an isolated storm or two may also evolve late
   tonight from the northeast Oklahoma vicinity to the Ozarks.

   ...Discussion...
   Aside from a few minor line adjustments, primarily to decrease the
   size of the thunder area over the Ozarks vicinity due to very meager
   -- and low-topped -- CAPE, the ongoing outlook continues to reflect
   current expectations.  No major changes are therefore required at
   this time.

   ..Goss.. 12/27/2021

   .PREV DISCUSSION... /ISSUED 1004 AM CST Mon Dec 27 2021/

   ...Upper Ohio Valley...
   A surface warm front currently extends across central OH into
   northern WV.  This boundary will lift slowly northward today into
   PA, with a warmer and marginally unstable air mass spreading into
   those areas.  Several 12z cams suggest the development of a few
   thunderstorms during the late afternoon/early evening across
   southeast OH, the northern panhandle of WV, and southwest PA. 
   Forecast soundings show sufficient elevated CAPE and cloud-bearing
   shear to pose a risk of small hail and/or gusty winds in the
   strongest cells.  At this time, the risk of severe storms appears
   low enough to keep probabilities less than 5%.

   ...OK/MO Vicinity...
   After midnight tonight, showers and a few elevated thunderstorms are
   expected to develop in a zone of intensifying low-level warm
   advection over eastern OK, southeast KS, southwest MO, and northwest
   AR.  No severe storms are anticipated.

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z