SPC AC 071937
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0237 PM CDT SUN SEP 07 2008
   
   VALID 072000Z - 081200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF FAR ERN
   CO...NRN KS AND SRN NEB...
   
   ...CNTRL PLAINS/CNTRL HIGH PLAINS...
   A ZONAL FLOW PATTERN IS IN PLACE ACROSS THE CNTRL PLAINS WITH WATER
   VAPOR IMAGERY SHOWING A PLUME OF MID-LEVEL MOISTURE EXTENDING FROM
   CNTRL CO EWD ACROSS NRN KS. AT THE SFC...A 1010 MB LOW IS PRESENT
   OVER NCNTRL CO WITH A BOUNDARY EXTENDING SEWD FROM THE LOW ACROSS NE
   CO...WRN KS INTO NRN OK. THE AIRMASS ACROSS THE CNTRL AND SRN PLAINS
   REMAINS CAPPED BUT ELEVATED INSTABILITY IS INCREASING ABOVE THE CAP
   WITH THE RUC SUGGESTING MUCAPE VALUES ACROSS SW KS RANGE FROM 1000
   TO 1500 J/KG. MODEL FORECASTS FAIL TO DEVELOP MUCH CONVECTION ACROSS
   THE SRN AND CNTRL PLAINS LATE THIS AFTERNOON INTO THE EVENING DUE TO
   THE CAP BUT DO AGREE INITIATING ELEVATED THUNDERSTORMS ALONG THE NRN
   EDGE OF THE INSTABILITY IN ERN CO LATE THIS EVENING. THIS CONVECTION
   SHOULD INITIATE NEAR THE BOUNDARY AND MOVE EWD ACROSS NRN KS DURING
   THE OVERNIGHT PERIOD AS THE LOW-LEVEL JET STRENGTHENS.
   
   FORECAST SOUNDINGS ACROSS NRN KS OVERNIGHT SHOW STRONG VERTICAL
   SHEAR AND SOMEWHAT STEEPENED MID-LEVEL LAPSE RATES SUGGESTING A
   THREAT FOR HAIL WILL EXIST WITH THE MORE ORGANIZED THUNDERSTORMS. IF
   AN ELEVATED SUPERCELL CAN DEVELOP...THEN A CORRIDOR OF HAIL WOULD BE
   POSSIBLE IN NRN KS LATE TONIGHT. ALTHOUGH LESS LIKELY...A MARGINAL
   WIND DAMAGE THREAT MAY ALSO DEVELOP IF AN ORGANIZED MCS CAN DRIVE AN
   INTENSE DOWNDRAFT THROUGH THE CAP.
   
   ...NM/FAR WEST TX...
   THUNDERSTORMS ARE CURRENTLY DEVELOPING ACROSS CNTRL NM ASSOCIATED
   WITH A SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY. RUC ANALYSIS
   SUGGESTS SEVERAL POCKETS OF MODERATE INSTABILITY ARE LOCATED FROM SW
   NM EXTENDING NEWD INTO THE ERN PLAINS OF NM WHERE MLCAPE VALUES
   RANGE FROM 1500 TO 2500 J/KG. IN ADDITION...SFC WINDS ARE BACKED
   ACROSS MUCH OF NM WHICH IS CREATING SUBSTANTIAL DIRECTIONAL SHEAR IN
   THE LOW TO MID-LEVELS AS SHOWN BY REGIONAL WSR-88D VWPS. THIS
   COMBINED WITH INSTABILITY AND STEEP MID-LEVEL LAPSE RATES EVIDENT ON
   FORECAST SOUNDINGS MAY BE SUFFICIENT FOR AN ISOLATED HAIL THREAT
   WITH THE STRONGER MULTICELLS.
   
   ...UPPER GREAT LAKES...
   WATER VAPOR IMAGERY SHOWS A BROAD LOW-AMPLITUDE UPPER-LEVEL TROUGH
   OVER THE UPPER MIDWEST. AT THE SFC...A COLD FRONT IS LOCATED ACROSS
   NW WI SWWD INTO SE MN. SCATTERED THUNDERSTORMS ARE DEVELOPING NEAR
   AND AHEAD OF THE BOUNDARY WHERE THE RUC SUGGESTS INSTABILITY IS WEAK
   ATTM. HOWEVER...MODERATE TO STRONG VERTICAL SHEAR EXISTS ACROSS MUCH
   OF THE REGION ACCORDING TO THE RUC WHICH COMBINED WITH COLD AIR
   ALOFT /500 MB TEMPS OF -20 TO -22C/ MAY BE SUFFICIENT FOR A MARGINAL
   HAIL THREAT THIS AFTERNOON.
   
   ..BROYLES.. 09/07/2008
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z