Jan 29, 2013 1630 UTC Day 1 Convective Outlook
Updated: Tue Jan 29 16:24:32 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...the most significant threat for severe thunderstorms is expected over parts of the ozark region and the lower mississippi valley this evening through tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20130129 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130129 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
20130129 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
20130129 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 291620
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1020 AM CST TUE JAN 29 2013
   
   VALID 291630Z - 301200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM THE ARKLATEX TO THE LOWER
   OH VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK...FROM
   ERN TX/OK TO THE LOWER MS VALLEY AND OH VALLEY...
   
   ...ERN OK/TX TO THE MS AND OH VALLEYS THROUGH TONIGHT...
   A LARGE-SCALE MID-UPPER TROUGH OVER THE HIGH PLAINS WILL PROGRESS
   EWD OVER THE LOWER PLAINS TO THE MS VALLEY BY EARLY WEDNESDAY. 
   WITHIN THE LARGE TROUGH...A PRIMARY SHORTWAVE TROUGH OVER THE SRN
   HIGH PLAINS...WITH AN ASSOCIATED 100 KT MIDLEVEL JET...WILL EJECT
   ENEWD TOWARD ERN OK/NW AR/MO OVERNIGHT.  LIKEWISE...AN ASSOCIATED
   SURFACE CYCLONE NOW IN N CENTRAL OK WILL DEEPEN AND MOVE NEWD ACROSS
   MO/IL TO LOWER MI...ALONG A PRE-EXISTING BAROCLINIC ZONE. 
   MEANWHILE...A BROAD MOIST SECTOR IS ALREADY ESTABLISHED FROM ERN
   TX/OK TO THE LOWER AND MID MS VALLEY REGION...WHERE BOUNDARY LAYER
   DEWPOINTS RANGE FROM THE UPPER 60S ALONG THE NW GULF COAST...TO
   56-60 F FARTHER N INTO MO/IL.  ADDITIONAL EWD EXPANSION OF THE MOIST
   SECTOR IS LIKELY THROUGH TONIGHT ACROSS THE MS/TN AND LOWER OH
   VALLEY REGION...IN RESPONSE TO THE DEEPEN CYCLONE AND A
   STRENGTHENING SLY LLJ.
   
   WIDESPREAD CONVECTION IS ONGOING ALONG AND JUST AHEAD OF THE SURFACE
   COLD FRONT FROM CENTRAL OK TO NRN MO.  THOUGH EXTENSIVE CLOUDS ARE
   PRESENT THROUGH MUCH OF THE WARM SECTOR...CONTINUED MOISTURE
   ADVECTION FROM THE S AND MODEST SURFACE HEATING IN CLOUD BREAKS WILL
   BOOST MLCAPE VALUES TO THE 1000-2000 J/KG RANGE ACROSS E TX AND SE
   OK THIS AFTERNOON...WITH LESSER BUOYANCY FARTHER TO THE E AND NE. 
   THERE ARE ALREADY INDICATIONS THAT ADDITIONAL PRE-FRONTAL CONVECTION
   WILL DEVELOP FROM NE TX INTO SE OK/WRN AR AND EVENTUALLY SRN MO THIS
   AFTERNOON ALONG THE MOIST AXIS.  VERTICAL SHEAR PROFILES WILL BE
   FAVORABLE FOR SUPERCELLS WITH AN ATTENDANT RISK FOR TORNADOES AND
   DAMAGING WINDS ACROSS THIS CORRIDOR.  FARTHER N...CONVECTION WILL
   GRADUALLY EVOLVE INTO A WELL-DEVELOPED QLCS WITH AN INCREASING RISK
   FOR DAMAGING WINDS LATER THIS AFTERNOON INTO EARLY TONIGHT...WITH A
   RISK OF EMBEDDED MESOVORTICES AND TORNADOES.
   
   THE GREATEST SEVERE RISK IS EXPECTED THIS EVENING THROUGH
   TONIGHT...BEGINNING AS THE PRE-FRONTAL CONVECTION NEAR AND NW OF THE
   ARKLATEX...AND CONTINUING OVERNIGHT AS ADDITIONAL PRE-FRONTAL
   CONVECTION FORMS WITHIN ONE OR MORE WARM SECTOR CONFLUENCE BANDS
   NEAR THE MS RIVER.  VERTICAL SHEAR WILL BE EXTREMELY STRONG WITHIN A
   MOIST ENVIRONMENT WITH AT LEAST WEAK SURFACE-BASED INSTABILITY. 
   THOUGH MLCAPE MAY ONLY REACH 500-750 J/KG...EFFECTIVE SRH OF 500-700
   M2/S2 IN ASSOCIATION WITH A 70-80 KT LLJ WILL SUPPORT THE POTENTIAL
   FOR A FEW STRONG TORNADOES WITH FAST-MOVING PRE-FRONTAL
   SUPERCELLS...AS WELL AS CIRCULATIONS EMBEDDED WITHIN WHAT WILL
   BECOME A WELL-FORMED SQUALL LINE.  WIDESPREAD AND SIGNIFICANT
   DAMAGING WINDS WILL ALSO BE POSSIBLE AS FAR NE AS THE LOWER OH
   VALLEY...WHERE 80+ KT FLOW JUST ABOVE THE SURFACE WILL COINCIDE WITH
   AT LEAST WEAK SURFACE-BASED BUOYANCY THROUGH MOST OF THE NIGHT.
   
   ..THOMPSON/COHEN.. 01/29/2013
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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