Dec 14, 2021 2000 UTC Day 1 Convective Outlook
Updated: Tue Dec 14 19:44:10 UTC 2021 (20211214 2000Z Day 1 shapefile | 20211214 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20211214 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
20211214 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
20211214 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
20211214 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 141944

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0144 PM CST Tue Dec 14 2021

   Valid 142000Z - 151200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Isolated thunderstorms are possible across eastern and south
   Florida, as well as from parts of southern California to the Four
   Corners region.

   ...Discussion...
   Ongoing outlook reasoning, and areas, continue to largely reflect
   current expectations.  The primary change with this update will be
   to remove the 10% thunder area from coastal portions of Washington,
   Oregon, and northern California.  While a stray inland flash or two
   could still occur in these areas, risk should diminish with time.

   ..Goss.. 12/14/2021

   .PREV DISCUSSION... /ISSUED 1023 AM CST Tue Dec 14 2021/

   ...CA today to the Four Corners overnight...
   A pronounced midlevel shortwave trough will progress inland over
   southern CA this afternoon/evening, and then continue
   east-northeastward to the Four Corners by the end of the period. 
   Strong forcing for ascent in a band preceding the midlevel trough
   will combine with modest lapse rates/weak buoyancy on the cyclonic
   side of the midlevel jet to support occasional lightning flashes
   with low-topped convection today across CA, and tonight from the
   southern Great Basin to the Four Corners.  Strong winds and
   sufficiently cold profiles suggest that the overnight convective
   band could be accompanied by snow squalls.

   ...FL Atlantic coast this afternoon through tonight...
   A weak inverted trough and a modifying air mass will continue to
   support the potential for a few thunderstorms near the east central
   and southeast Atlantic coast of FL.

   ...Middle TX coast today to the Ozarks overnight...
   Low-level moisture return is underway across the TX coast, where
   some shallow convection/showers are expected today, and some
   weak/elevated convection may spread as far north as the Ozarks
   overnight.  However, midlevel temperature profiles should remain
   sufficiently warm to inhibit deep convection/lightning through this
   forecast period.

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