Jan 9, 2012 1630 UTC Day 1 Convective Outlook
Updated: Mon Jan 9 16:12:03 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120109 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120109 1630 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
20120109 1630 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
20120109 1630 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.
   SPC AC 091607
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1007 AM CST MON JAN 09 2012
   
   VALID 091630Z - 101200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FOR PARTS OF SE
   TX AND SW LA...
   
   ...UPPER TX AND SW LA COASTAL PLAIN THROUGH TONIGHT...
   A MIDLEVEL LOW OVER THE TX BIG BEND THIS MORNING WILL PROGRESS ENEWD
   OVER CENTRAL TX BY TONIGHT.  DOWNSTREAM FROM THE MIDLEVEL LOW...A
   SURFACE CYCLONE IS EXPECTED TO FORM ALONG A PRE-EXISTING FRONT
   ACROSS SE TX BY THIS EVENING...AND THE LOW WILL DEVELOP NNEWD INTO E
   TX OVERNIGHT.  MEANWHILE...AN INFLUX OF MID-UPPER 60S BOUNDARY LAYER
   DEWPOINTS WILL CONTINUE ACROSS THE MIDDLE/UPPER TX COAST INTO SW LA
   IN ADVANCE OF THE WEAK SURFACE LOW.  WIDESPREAD CLOUDS WILL LIMIT
   DAYTIME HEATING...BUT THE RICH MOISTURE WILL HELP MAINTAIN MLCAPE
   VALUES NEAR 1000 J/KG ALONG THE UPPER TX COAST THROUGH THIS
   AFTERNOON.
   
   THE VWP FROM HOUSTON AND MODIFIED 12Z SOUNDINGS SHOW AN ENVIRONMENT
   SUPPORTIVE OF SUPERCELLS ACROSS THE UPPER TX COAST...WITHIN THE
   LARGER AREA OF CONVECTION THAT IS EXPECTED TO PERSIST AND SPREAD EWD
   THROUGH TONIGHT.  THE STORM ENVIRONMENT IS NEAR ITS PEAK IN TERMS OF
   INSTABILITY AND VERTICAL SHEAR...AND IT APPEARS THAT THE STRONGER
   FORCING FOR ASCENT AND VERTICAL SHEAR WILL GRADUALLY SHIFT NWD/NEWD
   AND AWAY FROM THE MOST UNSTABLE PART OF THE WARM SECTOR LATER THIS
   AFTERNOON INTO TONIGHT.  THUS...THE RISK FOR A TORNADO OR
   TWO...ALONG WITH DAMAGING WINDS AND LARGE HAIL...WILL LIKELY PEAK
   BETWEEN NOW AND EARLY AFTERNOON ACROSS THE UPPER TX COASTAL PLAIN
   /NEAR AND S OF THE HOUSTON METRO AREA/...AND THEN DIMINISH SOME
   LATER THIS AFTERNOON/EVENING.  OVERNIGHT...THE RISK FOR A TORNADO OR
   DAMAGING GUST WILL SPREAD INTO SW LA...WHERE THE STRONGER STORMS
   WILL MOVE INLAND FROM THE NW GULF.  THE MAGNITUDE OF INSTABILITY
   WELL INLAND FROM THE COAST WILL BE IN QUESTION AS A RESULT OF
   WIDESPREAD CONVECTION BETWEEN NOW AND TONIGHT FROM SE TX INTO W/SW
   LA.
   
   ..THOMPSON/COHEN.. 01/09/2012
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z