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Aug-29-2003 0600 UTC Day 1 Convective Outlook
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   SPC AC 290522
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1222 AM CDT FRI AUG 29 2003
   
   VALID 291200Z - 301200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 E
   EFK 45 SW ALB 35 SW IPT 45 WSW UNI 20 WNW SDF 45 SW EVV 35 WSW POF
   25 SSE HRO 10 ENE MLC 10 N SPS 40 SSW CDS 15 NNW PVW 15 N AMA 20 SSW
   GAG 25 NW END 25 WNW BVO 40 NNE JLN 40 SW JEF 35 SSW SPI 10 ESE DTW
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 ESE YUM 35 S EED
   45 W P38 20 E BAM 65 WNW OWY 50 ESE S80 25 NNW BIL 45 WNW OFK 20 SW
   CID 95 E APN ...CONT... 40 SSE CRP 20 SE SAT 35 S JCT 30 SSE DRT
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS ACROSS
   PORTIONS OF THE MIDDLE MS AND OH VALLEYS NEWD TO THE ERN GREAT LAKES
   AND NRN NEW ENGLAND...
   
   ...SYNOPSIS...
   PROGRESSIVE AND DEAMPLIFYING SHORT WAVE TROUGH WILL TRANSLATE EWD
   FROM THE NRN GREAT LAKES ACROSS SRN QUEBEC THIS PERIOD AND AID IN
   DRIVING A SURFACE COLD FRONT SEWD FROM THE ERN GREAT LAKES ACROSS
   NRN NEW ENGLAND BY EARLY SATURDAY. TRAILING PORTION OF THIS FRONTAL
   ZONE WILL EXTEND SWWD FROM LOWER MI INTO THE PLAINS OF KS EARLY
   TODAY. BY LATER TODAY AND TONIGHT THE BOUNDARY WILL SINK ONLY
   GRADUALLY SEWD TOWARD THE OH VALLEY...SWD INTO THE SRN PLAINS... AND
   SWWD FROM THE HIGH PLAINS INTO THE HIGHER TERRAIN OF CO/NM. STRENGTH
   OF MID LEVEL FLOW AND SYNOPTIC SCALE FORCING FOR ASCENT ABOVE THE
   FRONT WILL DECREASE WITH SWWD EXTENT BUT DEEPER CONVECTIVE COLD
   POOLS...DIFFERENTIAL HEATING...AND UPSLOPE FLOW BEHIND THE BOUNDARY
   IN CO/NM WILL CONTINUE TO SUPPORT CONVECTIVE DEVELOPMENT.
   
   ELSEWHERE...A COMPACT VORT MAX WILL MOVE EAST ACROSS THE NRN GREAT
   BASIN AND INTO NERN UT/SWRN WY BY LATE IN THE PERIOD...A TROPICAL
   IMPULSE WILL LIFT NWWD TOWARD THE TX/LA COAST...AND A SUBTROPICAL
   RIDGE ACROSS THE WRN ATLANTIC WILL MAINTAIN A VERY WARM AND MOIST
   AIRMASS ALONG THE ERN SEABOARD.
   
   ...ERN GREAT LAKES TO NERN NY/NWRN VT...
   AIRMASS ACROSS THIS AREA IS FORECAST TO DESTABILIZE ALMOST
   COINCIDENT WITH THE ARRIVAL OF STRONGER FORCING FOR ASCENT AHEAD OF
   THE FRONT. THIS SUGGESTS A GRADUALLY STRENGTHENING PREFRONTAL SQUALL
   LINE WITH INCREASINGLY STRONG DEEP LAYER SHEAR AND STRONG MID LEVEL
   DRY INTRUSION SUPPORTING SMALL SCALE BOWING LINE SEGMENTS AND
   PERHAPS ISOLD SUPERCELLS PRODUCING STRONG TO DAMAGING WIND GUSTS AND
   SOME HAIL FROM ABOUT 29/18Z THROUGH 30/00Z. AFTER DARK...BOUNDARY
   LAYER DECOUPLING AND LESSENING INSTABILITY ACROSS SERN NY/SRN NEW
   ENGLAND AND ERN ME SHOULD LIMIT SEVERE WIND POTENTIAL AS CONVECTIVE
   LINE WEAKENS AND MOVES INTO THESE AREAS.
   
   ...MS/OH VALLEYS...
   WLY COMPONENT OF THE DEEP LAYER FLOW ACROSS THE REGION SHOULD
   PROMOTE A SLOW ESEWD MOTION TO CONVECTIVE OUTFLOWS/EFFECTIVE FRONTAL
   BOUNDARY INTO AN INCREASINGLY UNSTABLE AIRMASS FROM SERN MO TO OH
   DURING THE AFTERNOON. DESPITE WEAK LAPSE RATES AND SOMEWHAT MARGINAL
   DEEP LAYER SHEAR...VERY MOIST AND WARMING BOUNDARY LAYER WILL
   SUPPORT MLCAPE VALUES TO 1500 J/KG AHEAD OF THE FRONT. EXPECT
   CLUSTERS OF PULSE AND POSSIBLY MULTICELLULAR STORMS CAPABLE OF
   PRODUCING WIDELY SCATTERED DAMAGING DOWNDRAFTS TO BE MOST LIKELY
   FROM LATE AFTERNOON INTO EARLY EVENING.
   
   ...SRN PLAINS...
   DIFFERENTIAL HEATING BETWEEN ANTICIPATED LARGE MASS OF CONVECTIVE
   DEBRIS AND/OR ONGOING CONVECTION OVER KS/NRN OK...AND STRONG
   INSOLATION FROM NWRN TX/SRN AND CNTRL OK SHOULD RESULT IN DEEPENING
   FRONTAL CIRCULATION...LOW LEVEL CONVERGENCE...AND LIFT FROM THE TX
   PNHDL ENEWD ACROSS OK INTO THE OZARKS. CONVECTION SHOULD INCREASE IN
   THIS ENVIRONMENT AS CAP SLOWLY WEAKENS AND MLCAPE CLIMBS TO BETWEEN
   1500 AND 2500 J/KG. WHILE WIND PROFILES ACROSS THE REGION ARE
   EXPECTED TO REMAIN UNEXCEPTIONAL...STEEP BOUNDARY LAYER LAPSE RATES
   AND NUMEROUS PULSE-TYPE STORMS COULD RESULT IN A SCATTERING OF
   STRONG WIND REPORTS.
   
   ...CAROLINAS/VA...
   INCREASING WLY LOW/MID LEVEL FLOW BETWEEN SUBTROPICAL RIDGE AND
   GREAT LAKES TROUGH COUPLED WITH STRONG SURFACE HEATING WILL AGAIN
   FAVOR THE DEVELOPMENT OF A LEE/THERMAL TROUGH AXIS FROM SC TO VA.
   VERY MOIST BOUNDARY LAYER WITH MID TO UPPER 70S DEW POINTS WILL
   CONTRIBUTE TO THE DEVELOPMENT OF VERY UNSTABLE CONDITIONS BY
   AFTERNOON. EXPECT AT LEAST ISOLD INTENSE STORMS WITH A DAMAGING WIND
   AND HAIL THREAT TO DEVELOP WITHIN THE TROUGH...AND PERHAPS ALONG BAY
   AND SEA BREEZES. LACK OF A LARGER SCALE FORCING/ORGANIZING MECHANISM
   CURRENTLY PRECLUDES HIGHER SEVERE WEATHER PROBABILITIES FOR THE
   AREA. HOWEVER...A SLGT RISK COULD BE ISSUED IN LATER OUTLOOKS IF
   GREATER SEVERE STORM COVERAGE IS ANTICIPATED.
   
   ...CO/NM...
   POST FRONTAL FORCED ASCENT INTO THE FOOTHILLS OF THE ROCKIES WILL
   LEAD TO INCREASING CONVECTIVE DEVELOPMENT WITHIN WEAKLY UNSTABLE
   AIRMASS DURING THE AFTERNOON. STRONG DIRECTIONAL AND SPEED SHEAR
   WITHIN THE STORM UPDRAFT LAYER COULD SUPPORT A FEW SUPERCELLS
   CAPABLE OF PRODUCING HAIL AND STRONG DOWNDRAFTS. STORM MOTION BASED
   POINT FORECAST SOUNDINGS SUGGEST CELLS WILL LIKELY REMAIN OVER THE
   HIGHER TERRAIN AND SOMEWHAT REMOVED FROM GREATER INSTABILITY EAST OF
   THE FOOTHILLS. A FEW SEVERE REPORTS ARE POSSIBLE BUT OVERALL THREAT
   AT THIS TIME DOES NOT APPEAR TO WARRANT HIGHER WIND/HAIL
   PROBABILITIES.
   
   ...GREAT BASIN...
   STRONG ASCENT AND DESTABILIZATION ASSOCIATED WITH COMPACT MID LEVEL
   DISTURBANCE SHOULD RESULT IN A FEW LINES OR ARCS OF HIGH-BASED TSTMS
   ROTATING AROUND VORT MAX AS IT DEVELOPS EAST ACROSS UT. INVERTED-V
   THERMODYNAMIC PROFILES COULD SUPPORT ISOLD MICROBURSTS WITH A FEW OF
   THE STRONGER STORMS.
   
   ..CARBIN/CROSBIE.. 08/29/2003
   
   ...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 1300Z
        
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