May 17, 2010 1730 UTC Day 2 Convective Outlook
Updated: Mon May 17 17:24:45 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20100517 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20100517 1730 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 171722
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1222 PM CDT MON MAY 17 2010
   
   VALID 181200Z - 191200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE
   SRN/CENTRAL HIGH PLAINS...
   
   ...SYNOPSIS...
   UPPER TROUGH OVER THE OH VALLEY WILL SHIFT ENEWD INTO NEW ENGLAND
   ...AS ANOTHER UPPER TROUGH DRIVES FROM CA EWD INTO THE CENTRAL/SRN
   ROCKIES. AT THE SURFACE...WEAK SURFACE LOW PRESSURE WILL BE LOCATED
   IN THE CAROLINAS...WITH A FRONT TRAILING SWWD TOWARD THE CENTRAL
   GULF COAST. FROM THE CENTRAL GULF COAST THE FRONT WILL EXTEND NWWD
   AS A QUASI-STATIONARY FRONT TO A LOW PRESSURE SYSTEM IN SERN CO. A
   DRYLINE IS FORECAST TO EXTEND SOUTH FROM THE CO LOW ACROSS EXTREME
   ERN NM/SWRN TX BY LATE AFTERNOON.
   
   ...CENTRAL HIGH PLAINS...
   AS UPPER LOW APPROACHES FROM THE WEST AND BECOMES NEGATIVELY
   TILTED...INCREASING DIFFLUENCE ALOFT WILL STRENGTHEN LOW LEVEL
   CONVERGENCE AND AID IN STORMS DEVELOPING NEAR AND EAST OF THE CO
   HIGHER TERRAIN BY MID AFTERNOON. ONCE STORMS DEVELOP... SELY
   BOUNDARY LAYER WINDS BENEATH MID LEVEL SWLY WINDS AT 30-50 KT WILL
   PROVIDE FAVORABLE SHEAR FOR SUPERCELLS. DEVELOPING SURFACE LOW
   PRESSURE WILL ADVECT AT LEAST MID/UPPER 50S NWWD INTO THE
   REGION...RESULTING IN AFTERNOON MLCAPES FROM 1000-2000 J/KG. LARGE
   HAIL IS EXPECTED TO BE THE MAIN THREAT...THOUGH VEERING WIND
   PROFILES WILL ALSO SUPPORT TORNADOES. THE HIGHEST THREAT FOR VERY
   LARGE HAIL AND POSSIBLY STRONGER TORNADOES WILL BE ACROSS  SERN CO
   WHERE VERTICAL SHEAR AND INSTABILITY WILL BE THE GREATEST.
   AS THE STORMS SPREAD EWD INTO SWRN KS TUESDAY NIGHT...WEAKENING
   INSTABILITY SUGGESTS THAT HAIL SHOULD BECOME THE PRIMARY THREAT. 
   
   ...SRN HIGH PLAINS...
   SHORTWAVE RIDGING WILL PERSIST ACROSS THE REGION THROUGH MOST OF THE
   DAY AND INHIBIT THUNDERSTORM DEVELOPMENT UNTIL LATE IN THE
   DAY...WITH INITIATION MOST LIKELY BETWEEN 21-00Z. STORMS ARE
   EXPECTED TO DEVELOP ALONG THE DRYLINE ACROSS FAR ERN NM AND THEN 
   SPREAD EWD INTO THE TX PANHANDLE TUESDAY EVENING. STORMS WILL BE IN
   AN ENVIRONMENT WITH 45 TO 55 KT OF DEEP LAYER SHEAR AND MLCAPES FROM
   1500 TO 2500 J/KG. THIS SHOULD RESULT IN INTENSE SUPERCELLS THAT
   PERSIST INTO THE EVENING HOURS WITH LARGE HAIL AND TORNADOES THE
   PRIMARY THREAT. HOWEVER...THE MOST INTENSE SEVERE WEATHER IS MOST
   LIKELY TO OCCUR ACROSS THE WRN OK/TX PANHANDLES AND ERN NM IN NARROW
   WARM SECTOR BETWEEN THE DRYLINE AND WARM FRONT. AFTER DARK...AS THE
   STORMS MOVE EWD INTO THE SLIGHTLY MORE STABLE BOUNDARY LAYER AIR
   MASS...THE THREAT FOR TORNADOES WILL DECREASE...BUT FORCING AND
   MODERATE INSTABILITY... ESPECIALLY ALOFT...WILL SUPPORT SEVERE
   HAIL/WIND DAMAGE OVERNIGHT INTO WRN OK/NWRN TX.
   
   ...ERN MT...
   A NARROW BAND OF HIGHER DEWPOINTS ARE FORECAST TO SURGE NWD INTO THE
   NRN HIGH PLAINS ON THE BACKSIDE OF SURFACE HIGH PRESSURE OVER THE
   UPPER MS VALLEY. THIS INCREASING BOUNDARY LAYER MOISTURE AND
   AFTERNOON HEATING WILL RESULT IN MLCAPES UP TO 1000 J/KG. WEAKLY
   CAPPED SOUNDINGS AND FORCING FROM APPROACHING UPPER LOW SHOULD BE
   SUFFICIENT FOR LATE AFTERNOON THUNDERSTORMS. DESPITE WEAK SHEAR
   ALOFT...STEEP LAPSE RATES AND MODERATE INSTABILITY MAY RESULT IN A
   FEW STORMS WITH HAIL.
   
   ...ERN CAROLINAS...
   PRESENCE OF WEAK FRONTAL BOUNDARY AND WEAK FORCING ASSOCIATED WITH
   AN APPROACHING 40-50 KT MID LEVEL WIND MAX IS EXPECTED TO  RESULT IN
   AFTERNOON/EVENING THUNDERSTORMS. DEEP LAYER SHEAR AT 30-40 KT WOULD
   SUPPORT STORM ORGANIZATION AND POSSIBLE SEVERE STORMS.
   HOWEVER...ONLY LOW SEVERE PROBS ARE FORECAST ATTM DUE TO WEAK MID
   LEVEL LAPSE RATES AND INSTABILITY.
   
   ..IMY.. 05/17/2010
   
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