May 23, 2011 0600 UTC Day 2 Convective Outlook
Updated: Mon May 23 06:05:36 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110523 0600 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20110523 0600 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
   SPC AC 230540
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1240 AM CDT MON MAY 23 2011
   
   VALID 241200Z - 251200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS LATE TUE AFTN INTO TUE NIGHT
   ACROSS CENTRAL AND EASTERN OKLAHOMA...MUCH OF CENTRAL AND EASTERN
   KANSAS...PARTS OF SOUTHWEST MISSOURI...NORTHWEST ARKANSAS AND NORTH
   CENTRAL TEXAS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
   AREA ACROSS MUCH OF THE CENTRAL PLAINS  INTO THE MIDDLE MISSISSIPPI
   VALLEY...EASTWARD THROUGH PARTS OF THE LOWER OHIO AND TENNESSEE
   VALLEYS...AND NORTHEASTWARD THROUGH THE NORTHERN MID ATLANTIC COAST
   STATES AND HUDSON VALLEY...
   
   ...AN OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES IS POSSIBLE
   LATE TUESDAY AFTERNOON AND EVENING...
   
   ...SYNOPSIS...
   MODELS INDICATE THAT THE LARGE-SCALE TROUGH...NOW DEVELOPING INTO
   THE WESTERN U.S...GRADUALLY SPLITS...WITH A SIGNIFICANT SOUTHERN
   PORTION SLOWLY LIFTING EAST NORTHEASTWARD OUT OF THE SOUTHERN
   PLATEAU BY EARLY TUESDAY...AS ANOTHER LARGE AND STRONG IMPULSE
   APPROACHES THE PACIFIC COAST.  THE LEAD TROUGH...WITH AT LEAST A
   COUPLE OF SIGNIFICANT EMBEDDED SMALLER SCALE IMPULSES...IS PROGGED
   TO EVOLVE INTO A CLOSED LOW AS IT MIGRATES ACROSS THE SOUTHERN
   ROCKIES INTO THE CENTRAL PLAINS LATER TUESDAY AND TUESDAY NIGHT. 
   ASSOCIATED FORCING FOR UPWARD VERTICAL MOTION APPEARS LIKELY TO
   CONTRIBUTE TO FURTHER DEEPENING OF A SURFACE CYCLONE OVER THE SOUTH
   CENTRAL PLAINS.  THIS IS EXPECTED TO BE ACCOMPANIED BY A
   STRENGTHENING SOUTHERLY LOW-LEVEL JET IN EXCESS OF 50 KT AT 850 MB
   BY EARLY TUESDAY EVENING...FROM NORTH CENTRAL TEXAS INTO EASTERN
   KANSAS...AS A CYCLONIC AND GENERALLY WESTERLY 70 KT 500 MB JET
   STREAK NOSES INTO AND THROUGH THE SOUTHERN PLAINS RED RIVER VALLEY
   REGION.
   
   AT THE SAME TIME...A LARGE COLD UPPER VORTEX WITH SEVERAL STRONG
   EMBEDDED SHORT WAVE IMPULSES WILL LINGER OVER MUCH OF EASTERN
   CANADA.  AN ASSOCIATED SIGNIFICANT COLD FRONT APPEARS LIKELY TO
   ADVANCE SOUTHEAST OF THE GREAT LAKES THROUGH MUCH OF THE
   NORTHEAST...AS ANOTHER IMPULSE...PERHAPS CONVECTIVELY
   ENHANCED...WITHIN THE SOUTHERN BRANCH OF THE SPLIT UPPER
   FLOW...LIFTS OUT OF THE OHIO VALLEY THROUGH SOUTHERN NEW ENGLAND BY
   12Z WEDNESDAY.
   
   GIVEN THE CONTINUING PRESENCE OF A SEASONABLY MOIST BOUNDARY LAYER
   AIR MASS IN THE WARM SECTOR OF THE PLAINS CYCLONE...AND ALONG AND
   AHEAD OF THE EASTERN COLD FRONT...DESTABILIZATION PROBABLY WILL
   BECOME SUFFICIENT TO SUPPORT CONSIDERABLE STRONG/SEVERE STORM
   DEVELOPMENT DURING THIS PERIOD.  ASIDE FROM SOME SEA BREEZE STORMS
   IN THE SOUTHEAST...THIS WILL MOSTLY REMAIN WEST AND NORTH OF
   PERSISTENT SUBTROPICAL RIDGING CENTERED JUST EAST OF THE SOUTH
   ATLANTIC COAST.
   
   ...CENTRAL/SOUTHERN PLAINS...
   LINGERING VARIABILITY AMONG THE MODELS AND ENSEMBLES CONCERNING THE
   TIMING AND TRACK OF THE TROUGH EMERGING FROM THE SOUTHWEST CONTINUES
   TO COMPLICATE THE FORECAST.  BUT IT APPEARS THAT THIS WILL ONLY
   IMPACT THE EXACT PLACEMENT OF THE HIGHEST SEVERE PROBABILITIES...AS
   THE EVOLVING LARGE-SCALE PATTERN SEEMS SUPPORTIVE OF A FAIRLY
   CLASSIC SEVERE WEATHER OUTBREAK.  AND ENOUGH COMMON GROUND APPEARS
   TO EXIST TO JUSTIFY AN UPGRADE TO MODERATE RISK SEVERE PROBABILITIES
   ACROSS MUCH OF CENTRAL/EASTERN KANSAS AND OKLAHOMA...PORTIONS OF
   NORTH CENTRAL TEXAS...NORTHWEST ARKANSAS AND SOUTHWEST MISSOURI.
   
   SURFACE DEW POINTS AROUND 70F ARE PROGGED IN THE WARM SECTOR OF THE
   DEEPENING CYCLONE...ALONG AND EAST OF A SHARPENING DRY LINE DURING
   THE LATE AFTERNOON HOURS...WHEN PEAK AFTERNOON HEATING AND
   STEEPENING LAPSE RATES ASSOCIATED WITH MID-LEVEL COOLING PROBABLY
   WILL CONTRIBUTE TO MIXED LAYER CAPE OF 2000-4000 J/KG.  AS THE
   MID-LEVEL JET NOSES INTO THE RED RIVER VALLEY...THE DRY LINE IS
   EXPECTED TO BECOME THE FOCUS FOR THE PRIMARY STORM DEVELOPMENT AS IT
   SURGES NORTHEASTWARD OUT OF SOUTH CENTRAL KANSAS...AND EASTWARD OUT
   OF CENTRAL OKLAHOMA...THROUGH MUCH OF EASTERN KANSAS AND OKLAHOMA BY
   LATE EVENING.  GIVEN THE ANTICIPATED WIND PROFILES...EXHIBITING
   STRONG DEEP LAYER SHEAR AND LARGE CLOCKWISE CURVED LOW-LEVEL
   HODOGRAPHS...THE ENVIRONMENT IS EXPECTED TO BECOME CONDUCIVE TO
   LONG-LIVED SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL AND
   STRONG TORNADOES.  THIS THREAT MAY CONTINUE THROUGH MUCH OF THE
   EVENING...PERHAPS INTO THE 06-09Z TIME FRAME...GRADUALLY SPREADING
   TOWARD THE LOWER MISSOURI VALLEY AND OZARKS...BEFORE DIMINISHING IN
   THE PRESENCE OF A MORE STABLE OR STABILIZING BOUNDARY LAYER.
   
   ...NORTHERN MID ATLANTIC STATES INTO THE LOWER HUDSON VALLEY...
   WEAK TO MODERATE DESTABILIZATION ALONG AND AHEAD OF THE
   SOUTHEASTWARD ADVANCING COLD FRONT...AND WITHIN THE PRE-FRONTAL LEE
   SURFACE TROUGH...IS EXPECTED TO PROVIDE THE FOCUS FOR VIGOROUS
   CONVECTIVE DEVELOPMENT WITH THE APPROACHING UPPER IMPULSE TUESDAY
   AFTERNOON.  MODELS ARE A BIT MORE UNCLEAR CONCERNING THE STRENGTH OF
   THE VERTICAL SHEAR...BUT IT SHOULD BE ENOUGH TO SUPPORT POTENTIAL
   FOR ORGANIZED STORM CLUSTERS...AND ISOLATED SUPERCELLS MAY NOT BE
   OUT OF THE QUESTION.  THIS COULD IMPACT MUCH OF THE URBAN
   CORRIDOR...FROM WASHINGTON D.C./BALTIMORE TO NEW YORK CITY...BEFORE
   CONVECTION DIMINISHING/SPREADS OFFSHORE WITH UPPER FORCING BY
   TUESDAY EVENING.
   
   ..KERR.. 05/23/2011
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z