Apr 13, 2007 1630 UTC Day 1 Convective Outlook
Updated: Fri Apr 13 16:36:10 UTC 2007
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the southern plains later today and tonight....   Please read the latest public statement about this event.

Categorical Graphic
20070413 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20070413 1630 UTC Day 1 Tornado Probabilities Graphic
Probabilistic Damaging Wind Graphic
20070413 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Probabilistic Large Hail Graphic
20070413 1630 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 131621
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1121 AM CDT FRI APR 13 2007
   
   VALID 131630Z - 141200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
   PARTS OF EAST TX...NORTHERN LA...AND SOUTHWEST AR...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SOUTHERN
   PLAINS AND LOWER MS VALLEY...
   
   POWERFUL UPPER TROUGH NOW SHOWN BY WATER VAPOR IMAGERY OVER SOUTHERN
   NM WILL TRACK EASTWARD ACROSS TX TONIGHT.  AHEAD OF THE
   SYSTEM...STRONG SOUTHERLY LOW LEVEL WINDS ARE TRANSPORTING RICH GULF
   MOISTURE NORTHWARD ACROSS PARTS OF TX/LA.  PRESENT INDICATIONS ARE
   FOR AN ACTIVE SEVERE WEATHER EVENT ACROSS PARTS OF NORTHERN TX INTO
   NORTHERN LA THIS AFTERNOON THROUGH TONIGHT...WITH A RISK OF A FEW
   STRONG TORNADOES...VERY LARGE HAIL...AND DAMAGING WINDS.
   
   CURRENT SURFACE ANALYSIS SHOWS MAIN LOW NORTH OF MAF...WITH WARM
   FRONT EXTENDING EAST-SOUTHEASTWARD TO NEAR ACT.  THIS BOUNDARY WILL
   LIFT NORTHWARD THROUGH THE DAY WITH MID/UPPER 60S DEWPOINTS
   SPREADING INTO MUCH OF NORTH-CENTRAL AND EAST TX.  MORNING OBSERVED
   AND FORECAST SOUNDINGS OVER THIS REGION SHOW STEEP MID LEVEL LAPSE
   RATES...FAVORABLE FOR THE DEVELOPMENT OF MODERATE INSTABILITY BY
   LATE THIS AFTERNOON.  SOUNDINGS ALSO SHOW RATHER WARM TEMPERATURES
   AT 700MB...SUGGESTING THAT CAPPING INVERSION WILL INHIBIT WARM
   SECTOR CONVECTION UNTIL LATER THIS AFTERNOON.
   
   STRONG WARM ADVECTION AND STRENGTHENING LOW LEVEL JET WILL HELP TO
   MAINTAIN A RISK OF SCATTERED STORMS ALONG AND NORTH OF WARM FRONT
   FROM NORTHWEST TX...ACROSS SOUTHERN OK...INTO SOUTHERN AR.  THERE IS
   A NARROW ZONE ALONG THE WARM FRONT OVER NORTHWEST TX WHERE STORMS
   COULD BECOME SURFACE-BASED WITH A RISK OF ISOLATED TORNADOES. 
   OTHERWISE...LARGE HAIL WILL BE THE MAIN THREAT.
   
   LATER THIS AFTERNOON...SUFFICIENT HEATING ALONG THE DRYLINE COMBINED
   WITH APPROACHING UPPER TROUGH WILL LIKELY RESULT IN SCATTERED
   THUNDERSTORMS WEST/SOUTHWEST OF THE DFW AREA.  OTHER ISOLATED CELLS
   MAY DEVELOP WITHIN THE WARM SECTOR WHERE LOW LEVEL WARM ADVECTION
   WILL BE OCCURRING.  VERTICAL SHEAR PROFILES THROUGHOUT THIS REGION
   WILL BE FAVORABLE FOR SUPERCELLS.  LOW LEVEL SHEAR AND MOISTURE
   PROFILES WILL ALSO BE QUITE FAVORABLE FOR TORNADOES /PERHAPS STRONG/
   AS STORMS SPREAD EASTWARD ACROSS NORTHEAST TX AND INTO LA DURING THE
   EVENING/NIGHT.  DAMAGING WINDS AND HAIL WILL ALSO BE POSSIBLE ACROSS
   THE MDT RISK AREA.
   
   OVERNIGHT...STORMS MAY BECOME MORE LINEARLY FORCED AS UPPER TROUGH
   SPREADS EASTWARD.  THIS WILL INCREASE THE RISK OF DAMAGING WINDS AS
   FAR EAST AS EASTERN LA AND WESTERN MS.
   
   ..HART/JEWELL.. 04/13/2007
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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