Apr 18, 2014 2000 UTC Day 1 Convective Outlook
Updated: Fri Apr 18 20:01:42 UTC 2014 (20140418 2000Z Day 1 shapefile | 20140418 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140418 2000 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20140418 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.
Probabilistic Damaging Wind Graphic
20140418 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.
Probabilistic Large Hail Graphic
20140418 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.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 31,674 10,417,534 Tampa, FL...St. Petersburg, FL...Orlando, FL...Cape Coral, FL...Gainesville, FL...
   SPC AC 181958

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0258 PM CDT FRI APR 18 2014

   VALID 182000Z - 191200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE FL
   PENINSULA...

   ...SUMMARY...
   WIDESPREAD/LOCALLY SEVERE THUNDERSTORMS WILL CONTINUE CROSSING THE
   FLORIDA PENINSULA THIS AFTERNOON AND OVERNIGHT.  ISOLATED SEVERE
   WIND GUSTS AND PERHAPS A TORNADO OR TWO ARE THE MAIN THREATS WITH
   THESE STORMS.

   ...DISCUSSION...
   FEW CHANGES ARE REQUIRED THIS FORECAST ASIDE FROM MINOR LINE
   TWEAKS...AS PRIOR FORECAST REASONING REMAINS VALID.  A LINE OF
   STORMS MOVING ACROSS THE WRN FL PENINSULA WILL REMAIN ASSOCIATED
   WITH THE PRIMARY SEVERE RISK OVER THE NEXT SEVERAL HOURS.  LIMITED
   THREAT MAY LINGER THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS
   AS THE MAIN UPPER SYSTEM CONTINUES SHIFTING EWD ACROSS THE SERN
   U.S./CENTRAL AND ERN GULF.

   ..GOSS.. 04/18/2014

   .PREV DISCUSSION... /ISSUED 1108 AM CDT FRI APR 18 2014/

   ...SYNOPSIS...
   WEAK...SLOWLY PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE ACROSS
   THE CONUS THROUGH SAT. ANY SVR WEATHER THREAT SHOULD OCCUR WITH LEAD
   SRN STREAM TROUGH THAT ATTM IS OVER THE CNTRL GULF CST. THIS TROUGH
   SHOULD MOVE E TO THE NERN GULF BY 12Z SAT...WITH SOME AMPLIFICATION
   LIKELY AS JET STREAK NOW OVER LA CONTINUES E AND THEN SE INTO THE
   BASE OF THE LARGER-SCALE SYSTEM.

   AT LWR LVLS...WEAK SFC WAVE ASSOCIATED WITH THE GULF CST
   TROUGH...NOW CENTERED S OF THE WRN FL PANHANDLE...SHOULD REDEVELOP
   SLOWLY E ALONG ASSOCIATED WARM/STNRY FRONT INTO THE NERN GULF BY
   EARLY TNGT. THIS LOW SHOULD CONTINUE E ACROSS THE NRN PART OF THE FL
   PENINSULA EARLY SAT AS TRAILING COLD FRONT AND PRE-FRONTAL SQLN MOVE
   ACROSS CNTRL AND SRN PARTS OF THE STATE. ANY SVR WEATHER THREAT THIS
   PERIOD SHOULD BE CONFINED TO STORMS WITHIN THE SQLN...AND TO ANY
   ADDITIONAL STORMS THAT FORM AHEAD OF IT LATER TODAY THROUGH TNGT.

   ...FL PENINSULA TODAY THROUGH TNGT...
   LIGHTNING AND...MORE RECENTLY...RADAR DATA SHOW LONG-LIVED
   PRE-FRONTAL SQLN MOVING E ACROSS THE ERN GULF OF MEXICO AT ABOUT 30
   KTS. THE SQLN SHOULD CONTINUE E ACROSS MUCH OF THE FL PENINSULA
   LATER TODAY THROUGH TNGT...WITH FORWARD-PROPAGATION CONTINUING TO BE
   FOSTERED BY /1/ MOISTURE-RICH SSELY LOW-LVL FLOW AND /2/ STEADY EWD
   PROGRESSION OF LARGE-SCALE TROUGH.

   THE SQLN LINE WILL REMAIN WELL E OF THE ASSOCIATED UPPER TROUGH. BUT
   SUFFICIENT /40 TO 50 KT/ WSWLY DEEP SHEAR SHOULD BE PRESENT OVER FL
   GIVEN CURRENT VWP DATA TO SUPPORT EMBEDDED SUSTAINED
   STORMS/SUPERCELLS WITH AN ATTENDANT RISK FOR SMALL BOWS/LEWPS WITH
   DMGG WIND AND POSSIBLY A TORNADO. AND...WHILE SFC HEATING WILL BE
   MODEST BY APRIL STANDARDS GIVEN ANTECEDENT CLOUDS...COMBINATION OF
   EVEN MODEST LOW-LVL DESTABILIZATION WITH CONVERGENCE ALONG
   SEA-BREEZE BOUNDARIES AND/OR ALONG DIFFUSE WARM FRONT MAY SUPPORT A
   FEW DISCRETE CELLS THIS AFTN THROUGH EARLY TNGT OVER N CNTRL AND E
   CNTRL PARTS OF THE STATE. GIVEN THE LIKELIHOOD FOR A PERSISTENT ELY
   COMPONENT TO THE NEAR-SFC FLOW AS THE MAIN SFC LOW REMAINS OVER THE
   NERN GULF...ONE OR TWO OF THESE STORMS COULD POSE A CONDITIONAL RISK
   FOR A TORNADO...IN ADDITION TO SVR HAIL.

   WHILE THE GREATEST RISK FOR SVR WEATHER SHOULD EXIST THIS AFTN
   THROUGH EARLY TNGT OVER CNTRL AND NRN PARTS OF THE FL PENINSULA...A
   MORE LIMITED SVR WEATHER RISK WILL LINGER THROUGH EARLY SAT OVER THE
   SERN PART OF THE STATE AS THE MAIN UPR TROUGH AND ITS ASSOCIATED
   CONVECTION/COLD FRONT CONTINUE SLOWLY EWD.

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