May 23, 2010 1300 UTC Day 1 Convective Outlook
Updated: Sun May 23 12:33:23 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20100523 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20100523 1300 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20100523 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20100523 1300 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 231231
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0731 AM CDT SUN MAY 23 2010
   
   VALID 231300Z - 241200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL U.S. FROM MN
   TO WEST TX...
   
   ...SYNOPSIS...
   HIGHLY AMPLIFIED MID LEVEL FLOW PATTERN WILL CONTINUE ACROSS THE
   CONUS WITH A SIGNIFICANT TROUGH DOMINATING THE WEST...AND A
   DOWNSTREAM BLOCKING RIDGE TAKING FORM FROM THE MS VALLEY TO THE
   GREAT LAKES. IN THE EAST...A WEAK CIRCULATION CENTER OVER PA/WV THIS
   MORNING WILL SETTLE TOWARD THE MID ATLANTIC SEABOARD...EVENTUALLY
   BECOMING ABSORBED INTO THE WRN FLANK OF LARGE OFFSHORE GYRE DRIFTING
   WWD.
   
   AS ONE STRONG DISTURBANCE IS EJECTED OUT OF THE WRN TROUGH AND LIFTS
   INTO CNTRL CANADA...SHORT WAVE RIDGING AND HEIGHT RISES WILL DEVELOP
   ATOP TRAILING FRONTAL ZONE FROM MN SWWD TO NRN KS. THE NEXT STRONG
   SHORT WAVE WITHIN THE LARGER SCALE TROUGH WILL MOVE FROM SRN CA TO
   THE FOUR CORNERS THIS PERIOD. HEIGHT FALLS AND STRENGTHENING
   DEEP-LAYER SWLY/SLY FLOW WILL OVERSPREAD THE ROCKIES AND ADJACENT
   HIGH PLAINS AND DRIVE CYCLOGENESIS OVER CO. RESULTANT SURFACE LOW
   AND WARM FRONT WILL DEVELOP NWD FROM CO/KS LATE TODAY TO NEB/SD
   BORDER AREA BY MONDAY MORNING. DIURNAL E-W OSCILLATIONS OF THE DRY
   LINE...TRAILING SOUTH FROM ERN CO TO WEST TX...WILL REMAIN WITHIN A
   NARROW RANGE GIVEN SIGNIFICANT MERIDIONAL COMPONENT TO THE LARGE
   SCALE FLOW.
   
   ...UPPER MS VALLEY...
   DESPITE LIMITED LARGE SCALE SUPPORT FOR ASCENT ALONG THE FRONT
   MOVING INTO THIS AREA...RICH BOUNDARY LAYER MOISTURE /SURFACE
   DEWPOINTS WELL INTO THE 60SF/ AND DIURNAL HEATING WILL CONTRIBUTE TO
   MODEST TO LOCALLY STRONG DESTABILIZATION. IT SEEMS PROBABLE THAT
   PERSISTENT CONVERGENCE ALONG THE FRONT...COMBINED WITH HEATING OF
   THE DAY...MAY BE SUFFICIENT TO OVERCOME INHIBITION AND SUPPORT
   SCATTERED CONVECTIVE INITIATION FROM THE ARROWHEAD OF MN SWD/SWWD
   ACROSS MN/NWRN WI. STRONGER DEEP-LAYER SHEAR WILL LAG THE FRONTAL
   ZONE BUT MAGNITUDE OF INSTABILITY SUGGESTS AT LEAST A LOW
   PROBABILITY THREAT OF HAIL/WIND.
   
   SEVERE WEATHER POTENTIAL MAY INCREASE AGAIN ACROSS WRN MN 
   LATE IN THE PERIOD AS THE NEXT SYSTEM APPROACHES AND LIFT ACROSS THE
   WARM FRONT BRINGS ANOTHER CHANCE FOR DEEP CONVECTION.
   
   ...CNTRL PLAINS...
   A DIFFICULT FORECAST CHALLENGE PRESENTS ITSELF ACROSS PARTS OF THE
   PLAINS WHERE FRONTAL ZONE IS NOW STALLING FROM SERN CO TO NRN KS
   BENEATH STRONG CAPPING INVERSION/EML. A WIDE ARRAY OF DETERMINISTIC
   MODEL SOLUTIONS ARGUE THAT PREDICTABILITY IN THIS REGIME IS LOW.
   LIFT ACROSS THE FRONT WILL INCREASE DURING THE SECOND HALF OF THE
   FORECAST PERIOD AS SIGNIFICANT SHORT WAVE TROUGH APPROACHES AND MASS
   ADJUSTMENT COMMENCES. UNTIL THEN...DESPITE PRONOUNCED DIURNAL
   DESTABILIZATION...STRONG CAP AND WEAK/NEUTRAL HEIGHT FALLS MAY
   PRECLUDE STORM INITIATION.
   
   PROBABILITY OF THUNDERSTORMS INCREASES SUBSTANTIALLY BETWEEN 21Z AND
   00Z NEAR AND NORTH OF TRIPLE POINT AND DEVELOPING WARM FRONT FROM
   NWRN KS/ERN CO INTO NEB. MAGNITUDE OF INSTABILITY AND SHEAR IN THESE
   AREAS WILL BE MORE THAN ADEQUATE FOR INTENSE/SUSTAINED CONVECTIVE
   DEVELOPMENT. SUPERCELLS WITH TORNADO POTENTIAL APPEAR QUITE POSSIBLE
   EARLY IN THIS DEVELOPMENT PROCESS...ESPECIALLY NEAR THE DEVELOPING
   WARM FRONT FROM NWRN KS/SRN NEB NWWD TO EXTREME SERN WY. FAST NEWD
   STORM MOTION SUGGESTS THAT SOME CELLS MAY MOVE FASTER THAN WARM
   FRONTAL RETREAT ACROSS THESE AREAS...BECOMING DECOUPLED FROM
   BOUNDARY LAYER INFLOW AND PRESENTING MORE OF A LARGE HAIL THREAT
   WITH TIME.
   
   SEVERE WEATHER THREAT IN THE FORM OF HAIL/WIND AND PERHAPS TORNADOES
   IS FORECAST TO EXPAND NWD OVER THE NRN PLAINS AND ADJACENT HIGH
   PLAINS THROUGH THE NIGHT AND INTO EARLY MONDAY AS STRONG FORCING FOR
   ASCENT ACCOMPANYING VIGOROUS TROUGH SPREADS NWD/EWD...LOW LEVEL JET
   INTENSIFIES...AND ABUNDANT INSTABILITY FUELS WIDESPREAD/ORGANIZED
   CONVECTION.
   
   ...SRN HIGH PLAINS...
   AT LEAST SCATTERED ROBUST CONVECTIVE DEVELOPMENT APPEARS LIKELY
   ALONG EXTENSIVE DRY LINE FROM CO/KS BORDER TO NM/TX BORDER THROUGH
   EARLY EVENING. STORMS WILL EXIST AMIDST CAPE AROUND 2000 J/KG AND
   SUFFICIENT SHEAR FOR SUPERCELLS. THIS DEVELOPMENT IS LIKELY TO BE
   SUSTAINED IN SOME FORM WELL AFTER DARK WITH THE APPROACH OF MORE
   SUBSTANTIAL FORCING FOR ASCENT WITH THE UPPER TROUGH MOVING EAST.
   THUS...THE PROBABILITY OF SEVERE HAIL AND WIND ACROSS THESE AREAS
   HAS BEEN INCREASED IN THIS OUTLOOK.
   
   ...CAROLINAS...
   SITUATION APPEARS SIMILAR TO YESTERDAY WITH PERHAPS SLIGHTLY GREATER
   DESTABILIZATION POSSIBLE DUE TO HIGHER BOUNDARY LAYER THETA-E AND
   COOLER TEMPS ALOFT. NWLY TO NLY FLOW OF 20-30KT AROUND THE BASE OF
   WEAK CIRCULATION DROPPING SOUTH ACROSS THE AREA COULD RESULT IN A
   COUPLE MORE ORGANIZED OR PERSISTENT CLUSTERS OF CONVECTION WITH SOME
   HAIL AND DAMAGING WIND POTENTIAL.
   
   ..CARBIN/ROGERS.. 05/23/2010
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z