SPC AC 072000
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0300 PM CDT SUN APR 07 2013
   
   VALID 072000Z - 081200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON THROUGH TONIGHT
   FOR NW OK...MUCH OF KS...AND WRN/CENTRAL MO...
   
   ...WESTERN/NORTHERN OK AND KS TO CENTRAL MO THROUGH TONIGHT...
   ONLY MINIMAL CHANGES TO EXISTING CONVECTIVE OUTLOOK...WITH LITTLE
   FLUCTUATION IN FORECAST REASONING AS PER PRIOR OUTLOOK DISCUSSION
   BELOW. OF INITIAL CONCERN IS ONGOING TSTM CLUSTER/SUPERCELL ACROSS
   SOUTHEAST KS INTO SOUTHWEST MO...REFERENCE SEVERE TSTM WATCH 83.
   REGARDING THE SOURCE REGION AIRMASS...THE 18Z OBSERVED SOUNDING FROM
   LAMONT OK IS INDICATIVE OF CONSIDERABLE MOISTENING WITHIN THE LOWEST
   1 KM SINCE 11Z...WITH VERY STEEP MID LEVEL LAPSE RATES AND MUCAPE OF
   AROUND 1500 J/KG. OTHERWISE...INITIALLY HIGH-BASED TSTMS SHOULD
   CONTINUE TO GRADUALLY INCREASE ACROSS WEST-CENTRAL KS THROUGH LATE
   AFTERNOON/EARLY EVENING...WITH MORE UNCERTAIN DEVELOPMENT
   PROGRESSIVELY FARTHER SOUTH ACROSS WESTERN OK/FAR NORTHWEST TX.
   
   ..GUYER.. 04/07/2013
   
   .PREV DISCUSSION... /ISSUED 1129 AM CDT SUN APR 07 2013/
   
   ...SYNOPSIS...
   A STRONG MIDLEVEL SHORTWAVE TROUGH WITH AN ASSOCIATED 100 KT JET
   STREAK WILL DIG SEWD TO CA/NV THROUGH TONIGHT...WHILE GRADUAL
   DOWNSTREAM HEIGHT RISES OCCUR OVER THE LOWER MS VALLEY AND SE
   STATES.  IN BETWEEN...A SERIES OF LOW-AMPLITUDE SPEED MAXIMA WILL
   PROGRESS FROM THE FOUR CORNERS TO THE OH VALLEY AND LOWER GREAT
   LAKES.  THE LARGELY WLY FLOW REGIME WILL CONTINUE TO SUPPORT LEE
   CYCLOGENESIS ACROSS THE HIGH PLAINS...AS WELL AS LOW-LEVEL MOISTURE
   TRANSPORT NWD ACROSS THE SRN/CENTRAL PLAINS.  
   
   ...NW OK/KS TO CENTRAL MO THROUGH TONIGHT...
   12Z SOUNDINGS AND RECENT SURFACE ANALYSES CONFIRM ONGOING LOW-LEVEL
   MOISTURE RETURN INTO TX/OK/KS FROM THE WRN GULF BASIN...THOUGH
   OBSERVATIONS SUGGEST THAT SHORT-TERM MODEL FORECASTS MAY BE A COUPLE
   DEGREES TOO HIGH WITH THE BOUNDARY LAYER DEWPOINTS THIS AFTERNOON. 
   MEANWHILE...THE EML NOTED IN THE AMA/MAF SOUNDINGS WILL CONTINUE TO
   OVERSPREAD NW TX AND WRN OK...LIKELY PROVIDING A SUFFICIENT CAP TO
   LIMIT CONVECTIVE INITIATION PROSPECTS ALONG THE WRN OK/NW TX DRYLINE
   AND NEAR THE WEAK SURFACE CYCLONE.  THE N EDGE OF THE WARMER EML
   RESIDES BETWEEN AMA AND DDC...AND EXTRAPOLATION SUGGESTS THAT THE
   MORE PROBABLE AREA FOR CONVECTIVE INITIATION THIS AFTERNOON/EVENING
   WILL BE NEAR AND N OF THE KS/OK BORDER. 
   
   MODIFIED FORECAST SOUNDINGS...ACCOUNTING FOR AFTERNOON TEMPS IN THE
   LOW-MID 70S WITH SOME CLOUDS AND BOUNDARY LAYER DEWPOINTS OF 58-60
   F...SUPPORT MLCAPE APPROACHING 2000 J/KG WITH ONLY SMALL CIN ACROSS
   NW OK AND ADJACENT AREAS OF KS.  ADDITIONALLY... WATER VAPOR IMAGERY
   SUGGESTS THE PRESENCE OF AN EMBEDDED SPEED MAX ALOFT OVER NRN NM AS
   OF MID MORNING...WHICH SHOULD REACH THE NW OK/SW KS BORDER REGION BY
   THIS EVENING.  THUS...THE EXPECTATION FOR AT LEAST ISOLATED
   THUNDERSTORM DEVELOPMENT NEAR OR N OF THE OK/KS BORDER APPEARS
   REASONABLE BY LATE AFTERNOON.  STORMS THAT FORM IN THIS AREA WILL
   LIKELY BECOME SUPERCELLS GIVEN THE MODERATE INSTABILITY AND
   EFFECTIVE BULK SHEAR NEAR 50 KT...AND BE CAPABLE OF PRODUCING
   ISOLATED VERY LARGE HAIL AND DAMAGING GUSTS.  A TORNADO OR TWO WILL
   BE POSSIBLE THIS EVENING WITH ANY SUPERCELLS ON THE N SIDE OF THE
   RICHER LOW-LEVEL MOISTURE AND AS LOW-LEVEL SHEAR INCREASES THIS
   EVENING IN CONJUNCTION WITH A STRENGTHENING LLJ.
   
   OTHERWISE...A NWD INCREASE IN MOISTURE AND THE ASSOCIATED LOW-LEVEL
   WAA REGIME SHOULD PROMOTE THE DEVELOPMENT OF THUNDERSTORM CLUSTERS
   BY THIS EVENING AND CONTINUE THROUGH TONIGHT ACROSS CENTRAL/NE KS
   INTO MO...WITH AN ATTENDANT RISK FOR ISOLATED LARGE HAIL AND
   DAMAGING WINDS.
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z