Dec 20, 2020 2000 UTC Day 1 Convective Outlook
Updated: Sun Dec 20 19:49:22 UTC 2020 (20201220 2000Z Day 1 shapefile | 20201220 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20201220 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 10,417 5,010,580 Tampa, FL...St. Petersburg, FL...Cape Coral, FL...Clearwater, FL...Spring Hill, FL...
Probabilistic Tornado Graphic
20201220 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
2 % 9,293 4,468,220 Tampa, FL...St. Petersburg, FL...Cape Coral, FL...Clearwater, FL...Spring Hill, FL...
Probabilistic Damaging Wind Graphic
20201220 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
5 % 10,397 5,018,343 Tampa, FL...St. Petersburg, FL...Cape Coral, FL...Clearwater, FL...Spring Hill, FL...
Probabilistic Large Hail Graphic
20201220 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 201949

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0149 PM CST Sun Dec 20 2020

   Valid 202000Z - 211200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
   WESTERN FLORIDA PENINSULA...

   ...SUMMARY...
   Isolated severe thunderstorms may affect parts of the western
   Florida Peninsula late this afternoon and evening.

   ...20z Update - Western FL Peninsula...

   The Marginal risk remains unchanged with this update. A strong storm
   offshore Manatee County showed weak to moderate rotation over the
   past hour or so. The storm has since weakened as it approaches the
   coast, where instability is much weaker than further west over the
   eastern Gulf waters. Nevertheless, as moisture continues to increase
   ahead of a surface cold front, some modest increase in instability
   is expected along the western Florida peninsula. Thunderstorms
   should increase in coverage and move inland through this evening,
   and a few strong storms are possible. For more details concerning
   the short-term risk, see MCD 1860.

   ..Leitman.. 12/20/2020

   .PREV DISCUSSION... /ISSUED 1029 AM CST Sun Dec 20 2020/

   ...Western Florida Peninsula...
   Clusters of thunderstorms are ongoing over the eastern Gulf of
   Mexico west/southwest of the Tampa/St Petersburg area at midday.
   This inland-spreading precipitation will tend to delineate the
   northward extent of modest surface-based destabilization this
   afternoon as mid/some upper 60s F surface dewpoints otherwise expand
   northward across the southern/central Florida Peninsula through
   early/mid-evening. Although the passing shortwave trough will tend
   to weaken into tonight, residually strong low/mid-level winds will
   support the possibility of well-organized storms/few supercells near
   and across the western Florida Peninsula as additional moistening
   and destabilization occur. A few damaging wind gusts and/or a
   tornado could occur late this afternoon and evening.

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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