Aug 13, 2008 1630 UTC Day 1 Convective Outlook
Updated: Wed Aug 13 16:11:15 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20080813 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080813 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080813 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080813 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 131607
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1107 AM CDT WED AUG 13 2008
   
   VALID 131630Z - 141200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST
   STATES...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CENTRAL
   PLAINS...
   
   ...SOUTHEAST STATES...
   A RATHER STRONG AND PROGRESSIVE SHORTWAVE TROUGH IS MOVING ACROSS
   THE SOUTHEAST STATES THIS MORNING...PROVIDING SHOWERS AND
   THUNDERSTORMS TO PARTS OF FL/GA/SC.  LOCAL VAD DATA AND MORNING
   RAOBS SHOW 50-60 KNOT WEST-SOUTHWESTERLY LOW LEVEL WINDS WHICH ARE
   RESULTING IN FAVORABLE LOW LEVEL VERTICAL SHEAR FOR OCCASIONAL
   UPDRAFT ROTATION.  WEAK LAPSE RATES AND SUBSTANTIAL CLOUD COVER ARE
   GREATLY LIMITING CAPE VALUES TO BELOW 500 J/KG. 
   NEVERTHELESS...THREAT FOR ISOLATED DAMAGING WIND GUSTS OR TORNADOES
   WILL CONTINUE THROUGH MUCH OF THE AFTERNOON AND EARLY EVENING UNTIL
   STORMS MOVE OFFSHORE.  REFERENCE WW 825 FOR FURTHER DETAILS.
   
   ...CENTRAL PLAINS...
   BROAD NORTHWEST FLOW PATTERN IS PRESENT TODAY OVER THE CENTRAL
   PLAINS STATES.  MORNING VISIBLE SATELLITE SHOWS MOSTLY CLEAR SKIES
   AND THE POTENTIAL FOR STRONG HEATING LATER TODAY.  RELATIVELY STEEP
   MID LEVEL LAPSE RATES WILL HELP YIELD AFTERNOON MLCAPE VALUES OF
   2000-3000 J/KG AND A RELATIVELY WEAK CAP.  MID LEVEL FORCING
   MECHANISMS ARE RATHER DIFFUSE AS AREA REMAINS UNDER MID LEVEL
   RIDGING.  HOWEVER...ALL MODEL GUIDANCE IS IN AGREEMENT THAT
   SCATTERED CLUSTERS OF STRONG STORMS WILL DEVELOP ALONG LEE-TROUGH
   OVER WESTERN NEB/EASTERN CO AS WELL AS OTHER REMNANT OUTFLOW
   BOUNDARIES...AND TRACK SOUTHEASTWARD ACROSS THE RISK AREA. 
   ORGANIZED MULTICELL AND OCCASIONAL SUPERCELL STORMS WILL POSE A
   THREAT OF HAIL AND DAMAGING WINDS.
   
   ...NORTHEAST STATES...
   STRONG DAYTIME HEATING IS EXPECTED TODAY OVER PARTS OF NY AND
   NORTHERN NEW ENGLAND AHEAD OF SHORTWAVE TROUGH WEST OF BTV. 
   MARGINAL INSTABILITY AND LARGE SCALE FORCING MAY RESULT IN AT LEAST
   ISOLATED THUNDERSTORMS.  COOL TEMPERATURES ALOFT AND STEEP MID LEVEL
   LAPSE RATES WILL PROMOTE A RISK OF HAIL IN STRONGER CELLS.  AN
   ORGANIZED SEVERE THREAT IS NOT CURRENTLY ANTICIPATED.
   
   ..HART/GRAMS.. 08/13/2008
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z