May 24, 2011 0600 UTC Day 1 Convective Outlook
Updated: Tue May 24 06:03:06 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110524 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110524 1200 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
20110524 1200 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
20110524 1200 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 240559
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1259 AM CDT TUE MAY 24 2011
   
   VALID 241200Z - 251200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF SOUTH CENTRAL
   AND SOUTHEAST KANSAS SWD INTO PARTS OF CENTRAL AND EASTERN
   OKLAHOMA...
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS CENTRAL AND SOUTHEAST
   KANSAS...CENTRAL AND EASTERN OKLAHOMA...AND INTO WESTERN ARKANSAS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND SWD TO THE
   MID-ATLANTIC REGION...AND WWD INTO THE PLAINS...
   
   ...SYNOPSIS...
   WITH CYCLONIC FLOW ALOFT TO PERSIST ACROSS THE NORTHEAST U.S. AND
   ERN CANADA...A STRENGTHENING MID-LEVEL SYSTEM -- ACCOMPANIED BY
   70-PLUS KT MID-LEVEL JET -- IS FORECAST TO EMERGE INTO THE CENTRAL
   AND SRN PLAINS.  BY THE END OF THE PERIOD...A DEEPENING UPPER LOW IS
   FORECAST ACROSS THE KS VICINITY -- WITH A 75 KT MID-LEVEL JET AROUND
   THE SRN PERIPHERY OF THIS SYSTEM.
   
   AT THE SURFACE...A COLD FRONT WILL CONTINUE ADVANCING ACROSS ERN
   CANADA...MOVING EWD INTO NEW ENGLAND THROUGH THE AFTERNOON BUT
   BECOMING MORE WASHED OUT ACROSS THE MIDWEST/OH VALLEY WITH TIME. 
   FARTHER W...A LEE LOW IS FORECAST TO MOVE VERY SLOWLY EWD/NEWD
   ACROSS KS/OK...BUT SHOULD STRENGTHEN THROUGH THE AFTERNOON AS THE
   UPPER LOW DEEPENS.  BY LATE AFTERNOON...A DRYLINE WILL EXTEND SWD
   ACROSS CENTRAL OK/CENTRAL TX AND A COMPOSITE WARM FRONT/OUTFLOW
   BOUNDARY SHOULD EXTEND SEWD ACROSS SRN KS/ERN OK AND INTO AR.  THIS
   SURFACE SYSTEM WILL BECOME A FOCUS FOR THE DEVELOPMENT OF A
   POTENTIALLY SIGNIFICANT SEVERE WEATHER OUTBREAK FOCUSED ON KS/OK/WRN
   AR THROUGH THE AFTERNOON AND EVENING HOURS.
   
   ...CENTRAL AND SRN PLAINS...
   A REGIONAL OUTBREAK OF SEVERE STORMS -- INCLUDING THE POTENTIAL FOR
   VERY LARGE HAIL...DAMAGING WINDS...AND SEVERAL LARGE/STRONG
   TORNADOES IS EXPECTED THIS AFTERNOON AND EVENING AS THE POWERFUL
   UPPER JET EMERGES INTO THE PLAINS DRIVING SURFACE CYCLOGENESIS.
   
   ELEVATED STORMS MAY BE ONGOING ACROSS PARTS OF NRN KS AND NEB AT THE
   START OF THE PERIOD...WHILE A CAPPED WARM SECTOR HINDERS STORM
   DEVELOPMENT INTO THE AFTERNOON HOURS.  BY MID AFTERNOON...SURFACE
   DEWPOINTS IN THE 60S TO NEAR 70 COMBINED WITH DAYTIME HEATING AND AN
   EWD SPREAD OF VERY STEEP MID-LEVEL LAPSE RATES ATOP THE WARM SECTOR
   WILL RESULT IN A VERY UNSTABLE ENVIRONMENT...WITH 100 MB MIXED-LAYER
   CAPE VALUES EXCEEDING 3000 TO 4000 J/KG ACROSS PARTS OF OK/KS AND
   INTO WRN AR E OF THE LOW/DRYLINE.  
   
   AS THE UPPER JET AND ASSOCIATED/DEEPENING UPPER SYSTEM EMERGE...A
   SLOWLY WEAKENING CAP SHOULD RESULT IN STORM INITIATION BY LATE
   AFTERNOON...FROM CENTRAL KS SWD INTO CENTRAL TX NEAR THE SURFACE LOW
   AND SWD ALONG THE DRYLINE.  WITH MODERATE/BACKED LOW-LEVEL FLOW
   AHEAD OF THE SURFACE LOW VEERING AND INCREASING RAPIDLY THROUGH THE
   LOWER TROPOSPHERE TO SWLY AT 50 TO 60 KT AT MID LEVELS...SHEAR VERY
   SUPPORTIVE OF BOTH MID-LEVEL AND LOW-LEVEL ROTATION WILL ALLOW
   STORMS TO RAPIDLY BECOME SUPERCELLULAR.  VERY LARGE HAIL...DAMAGING
   WINDS...AND SEVERAL POTENTIALLY SIGNIFICANT TORNADOES APPEAR LIKELY
   AS THE STORMS INCREASE AND SPREAD ACROSS KS/OK INTO WRN AR AND THEN
   LATER INTO WRN MO.  
   
   WHILE STORMS DEVELOPING SWD ACROSS CENTRAL TX ALONG THE DRYLINE
   SHOULD EVENTUALLY BEGIN DIMINISHING DURING THE EVENING AS BOUNDARY
   LAYER STABILIZATION/CAPPING BECOME REESTABLISHED...WIDESPREAD STORMS
   AND ASSOCIATED SEVERE POTENTIAL WILL CONTINUE INTO THE OVERNIGHT
   HOURS ACROSS KS/ERN OK/MO/AR.  SLIGHTLY ELEVATED STORMS SHOULD ALSO
   INCREASE INTO NEB/IA AND VICINITY...ALONG WITH SOME ACCOMPANYING
   SEVERE THREAT.  
   
   ...NEW ENGLAND SWD TO THE MID-ATLANTIC AND WWD INTO THE OH/TN/MID MS
   VALLEYS...
   SHOWERS AND SCATTERED THUNDERSTORMS MAY BE ONGOING AT THE START OF
   THE PERIOD...AND AS AIRMASS DESTABILIZES AHEAD OF THE SURFACE COLD
   FRONT AWAY FROM LINGERING CLOUDS/PRECIPITATION...EXPECT CONVECTION
   TO REDEVELOP/INTENSIFY THROUGH THE AFTERNOON.  
   
   THE BELT OF STRONGEST FLOW ALOFT IS FORECAST TO REMAIN S OF THE OH
   RIVER...BUT INSTABILITY MAY BE MORE LIMITED ACROSS PARTS OF THIS
   REGION DEPENDING UPON THE EVOLUTION OF AN ONGOING BOW APPROACHING
   THE MID MS VALLEY REGION ATTM.  OVERALL...EXPECT BROAD/WIDESPREAD
   ZONE OF SEVERE POTENTIAL NEAR AND SE OF THE COLD FRONT...WITH
   STRONGEST STORMS WITHIN MULTIPLE BANDS OF CONVECTION CAPABLE OF
   PRODUCING HAIL AND DAMAGING WINDS.
   
   ..GOSS.. 05/24/2011
   
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