Apr 18, 2014 1300 UTC Day 1 Convective Outlook
Updated: Fri Apr 18 12:42:36 UTC 2014 (20140418 1300Z Day 1 shapefile | 20140418 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140418 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20140418 1300 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 1300 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 1300 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 27,535 9,450,573 Tampa, FL...Orlando, FL...Cape Coral, FL...Palm Bay, FL...Sebring, FL...
   SPC AC 181239

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0739 AM CDT FRI APR 18 2014

   VALID 181300Z - 191200Z

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

   ...SUMMARY...
   SEVERE THUNDERSTORMS ARE POSSIBLE THROUGH THIS EVENING OVER THE
   FLORIDA PENINSULA.  THE MAIN ACTION AREA WILL MOVE FROM THE GULF OF
   MEXICO ONTO THE WEST COAST THEN INLAND...BUT A FEW STRONG TO SEVERE
   STORMS ARE POSSIBLE AHEAD OF THAT.  DAMAGING WIND IS THE MAIN
   HAZARD.  THESE STORMS ALSO MAY OFFER LARGE HAIL AND A TORNADO OR
   TWO.

   ...SYNOPSIS...
   MID-UPPER LEVEL PATTERN FEATURES SHORTWAVE TROUGH OVER INLAND PAC
   NW...RIDGING OVER ROCKIES...AND BROADLY CYCLONIC FLOW ACROSS MUCH OF
   SERN CONUS AND GULF OF MEXICO.  SHORTWAVE TROUGH -- NOW EVIDENT IN
   MOISTURE-CHANNEL IMAGERY OVER WRN AR AND EXTREME E TX -- IS FCST TO
   AMPLIFY AS IT MOVES ESEWD INTO PRE-EXISTING CYCLONIC REGIME.  THIS
   PROCESS SHOULD YIELD CLOSED 500-MB LOW OVER FL PANHANDLE BY
   06Z..MOVING EWD ROUGHLY ALONG I-10 TO FL COASTAL BEND/SWRN GA AREA
   NEAR END OF PERIOD.  THIS WILL SPREAD STRONGLY DIFLUENT BUT ALSO
   INCREASING WINDS ALOFT OVER OUTLOOK AREA.  MEANWHILE...BROAD/WEAK
   SRN-STREAM CYCLONE NOW OFFSHORE SRN CA WILL MOVE EWD TO AREAS NEAR
   OR S OF LAS...WITH TROUGH SWD ACROSS LOWER CO RIVER VALLEY AND
   NRN/CENTRAL BAJA BY 12Z.  

   AT SFC...CYCLONE NOW SE OF MS RIVER MOUTH IS PROGGED TO MOVE OR
   RE-DEVELOP THROUGH NRN PART OF ONGOING TSTM COMPLEX OVER NERN
   GULF...THEN MOVE NEWD ACROSS NWRN FL LATE AFTN INTO EVENING. 
   DIFFUSE WARM FRONTAL ZONE WAS ANALYZED AT 11Z FROM THAT LOW ESEWD
   THROUGH ERN-GULF PRECIP AREA AND CENTRAL FL PENINSULA.  ACCOMPANYING
   BAROCLINIC ZONE WILL SHIFT NWD SLOWLY TODAY...WITH SFC DEW POINTS TO
   ITS S MAINLY UPPER 60S/LOW 70S F. 

   ...FL PENINSULA...
   MAIN SVR THREAT IS EXPECTED TO SHIFT EWD OVER FL WITH TSTM COMPLEX
   NOW OVER ERN GULF...WHICH SHOULD CONTINUE TO MOVE SLOWLY EWD THROUGH
   MORNING INTO AFTN BEFORE ACCELERATING.  ADDITIONAL DEVELOPMENT IS
   POSSIBLE TO ITS E AND SE TODAY OVER PENINSULA...AND THIS EVENING
   ACROSS STRAITS/KEYS AND EXTREME ERN GULF...MOVING EWD TO NEWD ACROSS
   S FL.  LOW-LEVEL SHEAR SHOULD BE WEAKER WITH SWD DISTANCE AWAY FROM
   FRONTAL ZONE...ESPECIALLY ACROSS S FL...AND THIS FACTOR RENDERS
   UNCONDITIONAL SVR PROBABILITIES MORE MRGL WITH SWD EXTENT. 

   LOW-LEVEL THETAE ADVECTION NEAR WARM FRONT...ALONG WITH MUTED SFC
   HEATING...SHOULD CONTRIBUTE TO ANTECEDENT DESTABILIZATION AND
   500-1500 J/KG MLCAPE.  DEEP SHEAR IS EXPECTED TO INCREASE GRADUALLY
   THIS AFTN AHEAD OF MAIN MCS AS AFOREMENTIONED SHORTWAVE TROUGH
   STRENGTHENS/APCHS...DESPITE VEERING OF SFC WINDS TO SLY BEHIND WARM
   FROPA.  HODOGRAPH SIZE WILL BE LIMITED BY LACK OF MORE ROBUST
   NEAR-SFC WINDS...EVEN ALONG AND JUST N OF WARM FRONT WHERE FLOW IS
   MORE BACKED.  STILL...A FEW SUPERCELLS ARE POSSIBLE IN ADDITION TO
   ORGANIZED CLUSTERS/BOWS/LEWPS. 

   MOST MODELS...INCLUDING SREF MEMBERS...APPEAR TOO SLOW ALREADY WITH
   EWD PROGRESS OF GULF TSTMS AND LIKELY TOO LATE WITH ITS PASSAGE
   ACROSS FL THIS AFTN INTO EVENING.  SOME PRECURSORY/ANTECEDENT
   CONVECTION MAY OCCUR BEFORE MAIN MCS ARRIVES -- ESPECIALLY ALONG SEA
   BREEZES IN SRN PENINSULA WHERE STRONGEST DIABATIC HEATING IS
   EXPECTED AND THEREFORE MOST VIGOROUS SOLENOIDAL LIFT IS POSSIBLE. 
   HOWEVER...THIS POTENTIAL APPEARS MORE AND MORE CONDITIONAL/LIMITED
   WITH NWD AND WWD EXTENT AS THICK ANVIL MATERIAL SPREADS EWD OVER
   MOST OF FL.

   ..EDWARDS/ROGERS.. 04/18/2014

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z