SPC AC 171258
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0758 AM CDT WED SEP 17 2003
   
   VALID 171300Z - 181200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 ENE
   ELO 25 S FRM 10 NE SLN 35 WNW HUT 45 NNE DDC 40 SSW HLC 20 E LBF 40
   NE VTN 80 NE DVL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NE CMX 20 NW DBQ
   20 E IRK 35 NNE SGF 35 NW FYV 30 SSE CDS 45 WSW MRF.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 SSW TUS 25 WNW TUS
   60 N TUS 10 WSW SAD 15 SW SVC 30 W ALM 30 NW ROW 15 E CVS 35 ENE DHT
   25 ESE EHA 10 SSW GCK 50 SE GLD 40 WSW GLD 55 SW COS 35 N MTJ 45 S
   BPI 35 N BPI 35 W WRL 35 SSE SHR 40 N DGW 45 WNW CDR 40 NW PIR 25
   ENE MBG 60 NNE DVL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 SE TLH 30 NNE SSI.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 ESE P07 20 WNW JCT
   AUS 10 NNW GLS.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 ESE CHS 25 ENE FAY
   40 W ORF 30 ENE SBY.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF ERN ND...ERN
   SD...MN...NW IA...NEB...NRN KS...
   
   ...SYNOPSIS...
   A AMPLIFIED UPPER-TROUGH WILL SWING EWD INTO THE NRN AND CNTRL HIGH
   PLAINS TODAY. HURRICANE ISABEL WILL GRADUALLY MOVE TOWARD THE NC
   COAST BEING POSITIONED JUST OFF THE COAST LATE IN THE PERIOD. AT THE
   SFC..A COLD FRONT EXTENDING FROM SERN WY NEWD INTO ERN ND...WILL
   MOVE SWIFTLY SEWD REACHING THE UPPER MIDWEST AND SRN PLAINS BY LATE
   IN THE PERIOD.
   
   ...NRN AND CNTRL PLAINS...
   CURRENT ANALYSIS SHOWS SFC DEWPOINTS IN THE 60S F IN THE WARM SECTOR
   ACROSS THE CNTRL PLAINS AND AHEAD OF A COLD FRONT ACROSS THE
   DAKOTAS. AS SFC TEMPS WARM...MODERATE INSTABILITY WILL DEVELOP ALONG
   THE MOIST AXIS AND LOW-LEVEL CONVERGENCE NEAR AND JUST AHEAD OF THE
   FRONT MAY HELP INITIATE ISOLATED STORMS ACROSS THE ERN DAKOTAS AND
   WRN MN. HOWEVER...MORE WIDESPREAD CONVECTIVE DEVELOPMENT SHOULD HOLD
   OFF UNTIL LATE AFTERNOON WHEN LARGE-SCALE FORCING WILL INCREASE AS
   THE UPPER-TROUGH MOVES EWD INTO THE NRN HIGH PLAINS. CONVECTION WILL
   BE MOST INTENSE ALONG THE FRONT WITH ADDITIONAL CONVECTION CLOSER TO
   THE UPPER-TROUGH BEHIND THE FRONT ACROSS THE WRN DAKOTAS. STRONG
   MID-LEVEL FLOW WILL BE PRESENT WITH FORECAST SOUNDINGS SHOWING
   AROUND 60 KT AT 500 MB. THIS COMBINED WITH STRONG SLY FLOW IN THE
   WARM SECTOR WILL CREATE A FAVORABLE SHEAR ENVIRONMENT FOR ISOLATED
   SEVERE STORMS ACROSS THE SLIGHT RISK AREA. THE INTENSITY OF THE
   LOW-LEVEL JET AND CLOUD-LAYER FLOW PARALLEL TO THE COLD FRONT
   SUGGESTS A SQUALL-LINE MAY DEVELOP ACROSS THE ERN SD...ERN ND AND
   WRN MN DURING THE EVENING HOURS. THE STRONGEST SHEAR WILL EXIST IN
   THIS AREA WHERE A PLUME OF MODERATELY STEEP LAPSE RATES WILL ENHANCE
   THE LARGE HAIL POTENTIAL. ISOLATED DAMAGING WIND GUSTS WILL ALSO BE
   POSSIBLE ESPECIALLY WITH BOWING SEGMENTS IN THE LINE.
   
   FARTHER SOUTH ACROSS SCNTRL NEB AND WRN KS...A DRYLINE WILL BE
   PRESENT WITH SFC DEWPOINTS IN THE UPPER 60S F. ALTHOUGH MODERATE
   INSTABILITY WILL EXIST BY LATE AFTERNOON...A CAPPING INVERSION
   SHOULD KEEP CONVECTION FROM INITIATING DURING THE AFTERNOON.
   HOWEVER...AS THE LOW-LEVEL JET INTENSIFIES OVERNIGHT...SCATTERED
   STORMS SHOULD DEVELOP ACROSS SCNTRL NEB AND NCNTRL KS. STRONGER
   DIRECTIONAL SHEAR AND WEAKER LARGE-SCALE FORCING WILL FAVOR DISCRETE
   STORMS. MODERATE DEEP LAYER SHEAR SHOULD BE ENOUGH FOR SEVERE
   CONVECTION WITH THE POSSIBILITY FOR ISOLATED LARGE HAIL AND/OR
   DAMAGING WINDS.
   
   ...NC COAST...
   HURRICANE ISABEL WILL CONTINUE TO MOVE NWWD TOWARD THE COAST TODAY
   AND TONIGHT. THE OUTER RAINBANDS SHOULD BEGIN TO MOVE ONSHORE INTO
   ERN NC SOMETIME BETWEEN 08Z AND 12Z. FORECAST SOUNDINGS SHOW STRONG
   LOWER TO MID-LEVEL FLOW WILL EXIST AND MAY BE ENOUGH FOR ROTATING
   STORMS. THIS COMBINED WITH INCREASING LOW-LEVEL MOISTURE MAY BE
   ENOUGH FOR A MARGINAL TORNADO THREAT MAINLY ACROSS THE IMMEDIATE NC
   COAST LATE IN THE PERIOD.
   
   ..BROYLES/TAYLOR.. 09/17/2003
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1630Z