Apr 14, 2011 1630 UTC Day 1 Convective Outlook
Updated: Thu Apr 14 16:34:45 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the south-central plains this afternoon and tonight....   Please read the latest public statement about this event.

Categorical Graphic
20110414 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110414 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20110414 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20110414 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 141611
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1111 AM CDT THU APR 14 2011
   
   VALID 141630Z - 151200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM SERN KS/SWRN MO SWD THRU
   ERN OK FAR WRN AR INTO PORTIONS OF NERN TX...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS  OF THE CENTRAL
   AND SRN PLAINS INTO  PARTS OF THE LOWER MS VALLEY...
   
   ...CENTRAL AND SRN PLAINS...
   
   ...SEVERE THUNDERSTORM AND TORNADO OUTBREAK EXPECTED LATER THIS
   AFTERNOON AND TONIGHT...
   
   DEVELOPING UPPER LOW OVER CO/NM WILL DEEPEN ENEWD INTO CENTRAL KS BY
   TONIGHT AS POWERFUL UPSTREAM JET AND COLD ADVECTION ROTATE SEWD
   ACROSS SRN ROCKIES AND OUT INTO THE SRN PLAINS. SURFACE LOW NWRN OK
   DEEPENS NNEWD INTO KS THIS AFTERNOON WHILE A SECONDARY LOW TAKES
   SHAPE BY THIS EVENING SRN OK/TX BORDER IN RESPONSE TO APPROACH OF
   THE UPSTREAM JET AND LARGE SCALE ASCENT.
   
   PARAMETERS FAVORABLE FOR THE INITIATION OF THE FORECAST OUTBREAK OF
   SEVERE THUNDERSTORMS WILL FOCUS ON THE DRY LINE BY MID/LATE
   AFTERNOON.  FROM THE SURFACE LOW IN KS THE DRY LINE SHOULD MIX OUT
   TO A POSITION FROM NEAR RSL SSEWD TO ABOUT ICT AND THEN VICINITY
   I-35 INTO NRN TX.
   
   THE ONLY QUESTION WILL BE THE MOISTURE RETURN BUT GIVEN THE VERY
   STEEP LAPSE RATES AND STRONG HEATING...STRONG INSTABILITY WILL
   DEVELOP WITH MLCAPES AOA 2500 J/KG NWD AHEAD OF DRY LINE INTO
   CENTRAL/SERN KS.
   
   DISCRETE THUNDERSTORM DEVELOPMENT WILL TAKE PLACE BY MID/LATE
   AFTERNOON BENEATH STRONGLY DIFFLUENT UPPER JET SPREADING ACROSS THE
   DRYLINE. THE STRONG INSTABILITY COMBINED WITH STRONG DEEP LAYER
   VERTICAL WIND SHEAR /NEAR 70 KT IN THE 0-8 KM LAYER/ WILL FAVOR A
   FEW LONGER-LIVED SUPERCELLS. VERY LARGE HAIL WILL DEVELOP RATHER
   QUICKLY ONCE INITIATION OCCURS. LOW-LEVEL HODOGRAPH STRUCTURE ALSO
   FORECAST TO ENLARGE BY LATER THIS AFTERNOON AND EVENING AS LOW LEVEL
   JET BACKS AND INCREASES...WITH EFFECTIVE SRH VALUES INCREASING TO
   200-400 M2 S-2. THIS SUPPORTS THE DEVELOPMENT OF TORNADIC
   SUPERCELLS...WITH POTENTIAL FOR STRONG TORNADOS.
   
   WITH THE SECONDARY LOW DEVELOPMENT NEAR THE RED RIVER THIS
   EVENING...HIGH RES MODELS SUPPORT A GREATER POTENTIAL FOR LONG LIVED
   TORNADIC SUPERCELLS THIS EVENING ACROSS SERN OK. DEEPER MOISTURE AND
   THE DIFFLUENCE OF THE APPROACHING 120KT UPPER JET MAX WILL BE
   FOCUSING ON THIS AREA BY THIS EVENING AND IT WILL BE MONITORED FOR A
   POSSIBLE UPGRADE IN THE AFTERNOON UPDATE IF THIS SCENARIO SEEMS
   LIKELY TO PLAY OUT.
   
   SURFACE COLD FRONT CURRENTLY NWRN OK SWWD INTO TX PANHANDLE IS
   FORECAST TO RAPIDLY MOVE ACROSS ERN OK INTO WRN AR AFTER 00Z.
   STRENGTHENING LOW-LEVEL LINEAR FORCING FOR ASCENT IS EXPECTED TO AID
   IN UPSCALE GROWTH TO A QLCS STRUCTURE. THIS ACTIVITY WILL LIKELY
   MOVE ACROSS AR AND SRN MO OVERNIGHT...POSING A THREAT FOR DAMAGING
   WINDS. THERE WILL CONTINUE TO BE TORNADO POTENTIAL WITH EMBEDDED
   SUPERCELL STRUCTURES.
   
   ..HALES/STOPPKOTTE.. 04/14/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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