Apr 24, 2010 1300 UTC Day 1 Convective Outlook
Updated: Sat Apr 24 12:38:20 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the lower mississippi river valley...mid south and tennessee river valley today....   Please read the latest public statement about this event.

Categorical Graphic
20100424 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20100424 1300 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20100424 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20100424 1300 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 241235
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0735 AM CDT SAT APR 24 2010
   
   VALID 241300Z - 251200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS TODAY AND TONIGHT ACROSS PARTS
   OF CENTRAL/NORTHERN MS...CENTRAL/NORTHERN AL...AND A SMALL PART OF
   SOUTHERN MIDDLE TN...
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM EASTERN LA INTO WESTERN
   GA...AND NORTHWARD ACROSS MUCH OF TN/KY...INTO SOUTHEAST
   MO...SOUTHERN IL...AND SOUTHEAST IND...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE LOWER/MIDDLE
   MS...TN....AND OH VALLEYS...
   
   ...WIDESPREAD OUTBREAK OF SEVERE THUNDERSTORMS INCLUDING STRONG
   TORNADOES IS EXPECTED TODAY FROM THE MID MS AND LOWER OH VALLEYS
   SOUTHWARD INTO THE CENTRAL GULF COAST STATES...
   
   MORNING SATELLITE LOOPS SHOW A LARGE UPPER TROUGH OVER THE CENTRAL
   UNITED STATES...WITH A VIGOROUS SHORTWAVE TROUGH ROTATING ACROSS TX
   AND BECOMING NEGATIVELY TILTED.  THIS FEATURE WILL EJECT EASTWARD
   TODAY ACROSS THE MS/TN VALLEYS AND RESULT IN WIDESPREAD INTENSE
   THUNDERSTORM ACTIVITY.  MULTIPLE WAVES OF STRONG/SEVERE STORMS ARE
   POSSIBLE AND LEAD TO A COMPLEX FORECAST SCENARIO.
   
   ...LA/MS/AL/TN...
   THUNDERSTORMS HAVE BEEN INCREASING IN COVERAGE AND INTENSITY THIS
   MORNING ACROSS PARTS OF LA/AR/MS...ALONG AND AHEAD OF THE PRIMARY
   SURFACE COLD FRONT.  RAPIDLY STRENGTHENING LOW LEVEL WINDS AND WARM
   ADVECTION ARE LEADING TO DISCRETE CONVECTIVE INITIATION...WITH
   NUMEROUS STORMS SHOWING MID LEVEL ROTATION.  THIS ACTIVITY WILL
   SPREAD EASTWARD INTO AL AND TN WITH THE POTENTIAL FOR LARGE
   HAIL...DAMAGING WINDS...AND TORNADOES THROUGH THE MORNING.
   
   A FEW HOURS OF HEATING WILL LIKELY PROMOTE ANOTHER ROUND OF SEVERE
   STORMS BY EARLY AFTERNOON OVER EASTERN MS...MUCH OF AL...AND
   POTENTIALLY INTO MIDDLE TN.  THESE STORMS ARE FORECAST TO BE THE
   MORE SIGNIFICANT OF THIS EVENT...WITH THE RISK OF DAMAGING TORNADOES
   AND WIDESPREAD DAMAGING WINDS.  STORMS WILL TRACK EASTWARD INTO
   WESTERN GA DURING THE EVENING HOURS.
   
   ...MID MS AND LOWER OH VALLEYS...
   ALL MODEL GUIDANCE AGREES ON RAPID SURFACE CYCLOGENESIS OVER PARTS
   OF MO/IL BY EARLY AFTERNOON AS THE EXIT REGION OF A 90+ KNOT MID
   LEVEL SPEED MAX NOSES INTO THE AREA.  STRONG SOUTHEASTERLY LOW LEVEL
   WINDS WILL TRANSPORT MOISTURE NORTHWARD AND HELP TO DESTABILIZE
   PARTS OF MO/IL/IND/KY AHEAD OF THE SURFACE LOW.  FORECAST SOUNDINGS
   SUGGEST VERTICAL SHEAR AND CAPE PROFILES QUITE FAVORABLE FOR
   TORNADIC SUPERCELLS DURING THE AFTERNOON.  THE MAIN FORECAST
   QUESTION IN THIS AREA INVOLVES THE EVOLUTION OF CONVECTION FARTHER
   SOUTH AND WHETHER IT WILL IMPEDE MOISTURE RETURN THROUGH THE DAY.
   
   ..HART/SMITH.. 04/24/2010
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z