Dec 21, 2014 2000 UTC Day 1 Convective Outlook
Updated: Sun Dec 21 19:27:11 UTC 2014 (20141221 2000Z Day 1 shapefile | 20141221 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20141221 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
20141221 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
20141221 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
20141221 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 211927

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0127 PM CST SUN DEC 21 2014

   VALID 212000Z - 221200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...SUMMARY...
   NUMEROUS SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL OCCUR OVER
   PARTS OF FLORIDA AND SOUTHEAST GEORGIA THROUGH EARLY MONDAY.

   ...DISCUSSION...
   NO APPRECIABLE CHANGES NECESSARY THIS OUTLOOK. PLEASE SEE PREVIOUS
   DISCUSSION BELOW.

   ..GRAMS.. 12/21/2014

   .PREV DISCUSSION... /ISSUED 1015 AM CST SUN DEC 21 2014/

   ...SYNOPTIC SETUP...
   PATTERN WILL AMPLIFY OVER THE CONUS THROUGH MON AS STRONG JET STREAK
   THAT TOPPED E PACIFIC RIDGE YESTERDAY CONTINUES E/SE ACROSS THE
   RCKYS...RESULTING IN A BROAD TROUGH OVER THE PLNS AND REBOUNDING OF
   THE RIDGE N TOWARD THE BC CST. ON THE DOWNSTREAM SIDE OF THE
   TROUGH...A SERIES OF LOW-AMPLITUDE DISTURBANCES WILL MODULATE
   STRENGTH/LOCATION OF MOISTENING SWLY LOW-LVL FLOW ACROSS THE NRN
   GULF OF MEXICO AND ADJACENT SERN U.S. THE ERN PART OF WEAK FRONT NOW
   EXTENDING FROM THE CNTRL GULF ENE TO OFF THE NC CST SHOULD EDGE
   SLOWLY N ACROSS THE WRN ATLANTIC THIS PERIOD...WHILE THE REMAINDER
   OF THE BOUNDARY REMAINS MORE OR LESS STNRY OVER FL AND THE ERN GULF.


   ...SERN U.S. THROUGH EARLY MON...
   ISOLD TO WDLY SCTD TSTMS SHOULD PERSIST THROUGH MON IN BROAD SWATH
   OF SHALLOWER CONVECTION N OF STALLED SFC FRONT FROM THE CNTRL GULF
   ENE TO OFF THE CAROLINA CST. MODEST MID-LVL LAPSE RATES AND WEAK
   LARGE-SCALE FORCING FOR ASCENT WILL LIMIT UPDRAFT STRENGTH AND
   DEPTH...WITH FCST SOUNDINGS SUGGESTING ELEVATED MUCAPE REMAINING
   MAINLY AOB 500 J/KG. A WEAKLY ORGANIZED CLUSTER OF SHOWERS/STORMS
   MAY...HOWEVER...AFFECT W CNTRL PARTS OF THE FL PENINSULA TNGT/EARLY
   MON...WHERE THE MOST SUBSTANTIAL MOISTURE /PW TO 2 INCHES/ AND
   GREATEST LOW-LVL CONFLUENCE IS LIKELY TO EXIST AHEAD OF UPR IMPULSE
   NOW OVER THE NWRN GULF.

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