Jun 20, 2011 1630 UTC Day 1 Convective Outlook
Updated: Mon Jun 20 16:08:06 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

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

Categorical Graphic
20110620 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110620 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
20110620 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
20110620 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 201603
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1103 AM CDT MON JUN 20 2011
   
   VALID 201630Z - 211200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
   PORTIONS OF EASTERN NEB...WESTERN IA...SOUTHEAST SD...EAST KS...
   NORTHWEST MO SWD THROUGH CENTRAL OK......
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL/SOUTHERN
   PLAINS EASTWARD TO THE OH VALLEY...THEN SOUTHEASTWARD TO THE
   CAROLINAS...
   
   ...CENTRAL/SRN PLAINS...
   UNSEASONABLY STRONG UPPER LOW MOVING FROM CURRENT POSITION SE CO
   NEWD ACROSS WRN KS INTO SRN NEB BY 12Z TUE. 60-70KT 500MB JET MAX
   WITH ASSOCIATED STRONG ASCENT/DIVERGENCE SPREADING NEWD FROM CENTRAL
   HIGH PLAINS ACROSS KS INTO NEB THIS AFTERNOON. SURFACE LOW OVER
   W-CENTRAL KS WILL MOVE SLOWLY NNEWD INTO SRN NEB. THE DRY LINE
   EXTENDING FROM THE LOW SWD THRU FAR WRN OK/SWRN TX WILL SHIFT EWD BY
   MID AFTERNOON TO EXTEND ON A N/S AXIS VICINITY THE I-35 CORRIDOR.
   
   VERY STRONG SLY WINDS AHEAD OF DRY LINE WILL WRAP NWWD THE MOIST AND
   UNSTABLE AIR MASS TO N OF SURFACE LOW INTO CENTRAL NEB.
   
   THE STRONG LARGE SCALE ASCENT COUPLED WITH THE POST FRONTAL MOIST
   NLY FLOW WRN KS THIS AM HAS GENERATED ELEVATED SEVERE THUNDERSTORMS.
   
   
   BY MID AFTERNOON CONDITIONS WILL RAPIDLY DEVELOP TO SUPPORT AN
   OUTBREAK OF SEVERE THUNDERSTORMS BOTH ALONG THE DRY LINE AND IN THE
   VERY FAVORABLE SHEAR AND LARGE SCALE ASCENT REGION TO THE N/NE OF
   THE SURFACE LOW ACROSS NEB.
   
   THE STRONGLY SHEARED PROFILES AHEAD OF THE SURFACE LOW OVER ERN NEB
   COUPLED WITH MLCAPES CLIMBING TO AOA 2000 J/KG EXPECTED TO SUPPORT
   TORNADIC SUPERCELL DEVELOPMENT BY MID/LATE AFTERNOON.  THERE IS THE
   POTENTIAL OF STRONG TORNADOES GIVEN THE ENVIRONMENT THAT WILL BE IN
   PLACE.
   
   DOWN THE DRY LINE SCATTERED SUPERCELLS WILL DEVELOP AS THE CAP
   BREAKS BY MID/LATE AFTERNOON. BY THAT TIME MLCAPES WILL HAVE CLIMBED
   TO AOA 2500 J/KG SWD TO THE OK/TX BORDER WHICH WHEN COUPLED WITH THE
   PRESENCE OF THE MID LEVEL JET MAX AND VERY STEEP LAPSE RATES WILL
   RESULT IN A VERY LARGE HAIL POTENTIAL ALONG WITH DAMAGING DOWNBURST
   WINDS.  IT NOW APPEARS COVERAGE OF BOTH THE HAIL AND WIND WILL BE
   SUFFICIENT TO UPGRADE THE RISK TO MDT AS FAR S AS THE OKC AREA . 
   THERE WILL ALSO BE THE POTENTIAL FOR TORNADOES GIVEN THE 50-60 KT OF
   SHEAR.  FURTHER S INTO NCENTRAL TX THE EXPECTED COVERAGE WILL BE
   LESS BUT THERE IS STILL POTENTIAL OF VERY LARGE HAIL AND DAMAGING
   DOWNBURSTS.
   
   UPSCALE ORGANIZATION OF ONE OR MORE CLUSTERS IS ONCE AGAIN POSSIBLE
   TONIGHT WITH THE RISK OF WIDESPREAD DAMAGING WINDS AS STORMS SPREAD
   INTO IA/MO.
   
   ...OH VALLEY TO CAROLINAS...
   A BAND OF MODERATELY STRONG MID LEVEL WINDS EXTENDS FROM IND/OH INTO
   THE CAROLINAS TODAY.  THE PRIMARY LOW LEVEL INSTABILITY GRADIENT
   WILL ALSO RUN ALONG THIS CORRIDOR.  MULTIPLE CLUSTERS OF STRONG TO
   SEVERE THUNDERSTORMS ARE LIKELY OVER THIS REGION THIS AFTERNOON AND
   TONIGHT.  DAMAGING WINDS WOULD BE THE MAIN THREAT ASSOCIATED WITH
   BOWING SEGMENTS...ALTHOUGH THE STRONGEST STORMS COULD ALSO PRODUCE
   LARGE HAIL.
   
   ..HALES/HURLBUT.. 06/20/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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