SPC AC 230559
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1259 AM CDT WED JUN 23 2004
   
   VALID 231200Z - 241200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 NE
   TOL PIA LWD DSM LSE 35 NNE APN.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 ESE
   ECG EWN FLO 40 NW CAE GSP HKY LYH WAL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 NNW ERI 25 WSW CLE
   20 W HUF 25 WSW STL CNK 30 WSW EAR 30 NNW IML 25 SSW SNY LIC 35 NNE
   LAA GCK 25 SSW GAG 40 NNW CDS 45 NNE BGS 40 SSW ABI 15 SSE BWD 35 NE
   ACT 45 SSW PRX 15 NE PGO 40 SE HRO 25 SSE PAH 20 NW SDF 15 NNE UNI
   20 WSW DUJ SYR 45 W GFL 10 WSW ALB 20 SE ABE 35 SSW ACY ...CONT...
   15 SSW BHB 35 NNW BML ...CONT... 40 NE HVR 60 NNW MLS 55 SW DIK 15
   NNE Y22 30 S BIS 45 ENE BIS 75 NE MOT ...CONT... 70 ESE YUM 25 SE
   EED 45 ESE LAS 45 SSE SGU 35 NE GCN 50 NNE INW 15 W GUP 50 SSE FMN
   35 E GUC 45 NW LAR 25 SSW LND 50 S BPI 25 SW PUC 35 SE U24 55 SSE
   ELY 50 SW ELY 35 NE U31 25 W U31 20 NE BIH 35 WSW BIH 35 NE MER 60
   NW TVL 65 E 4LW 50 NNE 4LW 35 NNE LMT 40 WSW MHS 20 ESE CEC 45 SSE
   OTH 35 SSE EUG 15 E PDX 30 SE OLM 30 ENE SEA 20 NE BLI.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CAROLINAS...SERN VA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ERN IA TO LOWER MI...
   
   ...SYNOPSIS...
   DEEP MID-UPPER LEVEL CYCLONE WILL REMAIN OVER HUDSON BAY REGION AND
   NRN ONT.  ASSOCIATED BROAD BELT OF CYCLONIC FLOW ALOFT WILL CONTINUE
   ACROSS NRN PLAINS...GREAT LAKES AND UPPER MS VALLEY REGIONS. 
   UPSTREAM LONGWAVE RIDGE WILL REMAIN ANCHORED OVER GREAT
   BASIN...PACIFIC NW STATES AND WRN CANADA.  MOST SIGNIFICANT
   SHORTWAVE TROUGH  -- NOW OVER N-CENTRAL PORTION OF MANITOBA/SASK
   BORDER -- SHOULD DIG SEWD ACROSS ERN ND AND NRN MN DURING AFTERNOON.
    IN SRN STREAM...SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL
   IMAGERY OVER NERN MEX -- IS EXPECTED TO LIFT SLOWLY NEWD ACROSS S
   TX.  MEANWHILE WEAKER DOWNSTREAM PERTURBATION NOW OVER ARKLATEX
   REGION SHOULD ACCELERATE ENEWD ACROSS SRN APPALACHIANS.
   
   AT SFC...COLD FRONT NOW ANALYZED FROM SRN MN SWWD TO SWRN WY IS
   EXPECTED TO MOVE EWD/SEWD ACROSS WI/MI/IA AND NRN IL...AS WELL AS
   ADJOINING PORTIONS LS/LM/LH...THROUGH PERIOD.  APCH OF SRN STREAM
   PERTURBATION IS PROGGED TO AID CYCLOGENESIS ALONG SFC BAROCLINIC
   ZONE OVER NC/SERN VA DURING DAY...WITH LOW MOVING ENEWD TOWARD
   HAMPTON ROADS REGION.
   
   ...VA/NC....
   TSTMS IN CLUSTERS AND/OR BANDS SHOULD FORM THROUGH AFTERNOON AND
   MOVE ENEWD TOWARD COASTAL TIDEWATER REGION WITH MAIN SEVERE THREAT
   BEING DAMAGING WIND.  GREATEST CONCENTRATION OF ACTIVITY SHOULD BE
   NEAR FRONT AND LOW...BUT CAP SHOULD WEAKEN ENOUGH AMIDST SFC HEATING
   TO ALLOW WIDELY SCATTERED TSTMS TO DEVELOP ACROSS MUCH OF PIEDMONT
   AND COASTAL PLAIN REGION OF CAROLINAS. ISOLATED HAIL OF MARGINAL
   SEVERITY IS POSSIBLE...AND A TORNADO OR TWO MAY OCCUR.
   
   VERTICAL SHEAR AND SFC CONVERGENCE SHOULD BE MAXIMIZED THROUGHOUT
   AFTERNOON AND EARLY EVENING FROM SFC LOW ENEWD ALONG FRONT. 
   SUPERCELL POTENTIAL SHOULD BE MAXIMIZED IN THIS CORRIDOR NEAR
   CENTRAL/ERN VA/NC BORDER...WHERE 40-50 KT SFC-6 KM SHEARS ARE
   POSSIBLE.  PRIND POTENTIAL FOR LONG-LIVED SUPERCELLS AND HIGHER
   TORNADO PROBABILITIES WILL BE LIMITED BY COMBINATION OF
   1. INTERFERENCE FROM SCATTERED-NUMEROUS CONVECTION IN VICINITY AND
   2. WEAK LOW LEVEL ABSOLUTE FLOW -- GENERALLY 10 KT OR LESS BELOW 800
   MB -- LIMITING 0-1 AND 0-3 KM HODOGRAPH SIZE.
   STILL...A FEW SUPERCELLS AND BOW ECHOES RE POSSIBLE AMIDST AMBIENT
   REGIME OF ORGANIZED MULTICELL CONVECTION.
   
   ALTHOUGH MIDLEVEL LAPSE RATE WILL BE ONLY SLIGHTLY GREATER THAN
   MOIST-ADIABATIC...MLCAPE VALUES 1500-2000 J/KG WILL BE POSSIBLE BY
   MID-AFTERNOON S OF FRONT...GIVEN STRONG SFC HEATING AND UPPER
   60S/70S F SFC DEW POINTS.  ORGANIZED SEVERE THREAT SHOULD DIMINISH
   WITH SWD EXTENT TOWARD GA AND FL AS MIDLEVEL FLOW AND DEEP-LAYER
   SHEAR WEAKENS...AND WITH SWWD EXTEND ACROSS MS DELTA REGION...THOUGH
   ALMOST ANY TSTM IN THIS VERY MOIST AND DIURNALLY HEATED REGIME MAY
   SPAWN WET MICROBURSTS.
   
   ...GREAT LAKES/UPPER MS VALLEY...
   WIDELY SCATTERED TO SCATTERED TSTMS ARE EXPECTED TO DEVELOP --
   MAINLY FROM AFTERNOON INTO EARLY EVENING -- INVOF COLD FRONT.  SOME
   CONVECTION MAY ORGANIZE INTO CLUSTER OR LINE WITH BOW ECHOES.
   LARGE HAIL AND DAMAGING GUSTS APPEAR ABOUT EQUALLY PROBABLE FROM
   THIS ACTIVITY. CONVECTION WILL BE STRONGLY TIED TO DIURNAL HEATING
   INFLUENCE ON BOUNDARY LAYER INSTABILITY...AS WELL AS NEAR-FRONTAL
   CONVERGENCE...AND SHOULD DIMINISH AFTER DUSK.  COVERAGE MAY BE
   LIMITED BY WLY COMPONENT OF PREFRONTAL FLOW AND RESULTING REDUCTION
   IN CONVERGENCE...HOWEVER CAP SHOULD WEAKEN ENOUGH IN PRESENCE OF
   DIABATIC HEATING SUCH THAT FRONTAL LIFT CAN STILL INITIATE TSTMS. 
   NEARLY UNIDIRECTIONAL DEEP-LAYER FLOW IS FCST BUT WITH UP TO 50 KT
   DEEP-LAYER SPEED SHEAR.
   
   ...UPPER MIDWEST...
   ADDITIONAL CONVECTION MAY DEVELOP AROUND 00Z ALONG SECONDARY COLD
   FRONT -- FARTHER NW ACROSS ERN ND/NRN MN AREA. SEVERE PROBABILITIES
   ARE MORE MARGINAL/CONDITIONAL IN THIS AREA BECAUSE OF CONCERNS ABOUT
   SUFFICIENT MOISTURE/INSTABILITY.  BOUNDARY LAYER INSTABILITY WILL BE
   WEAKER OVER THIS REGION THAN FARTHER SE...LIMITING
   INTENSITY/DURATION OF SEVERE THREAT.  HOWEVER...THIS SHOULD BE
   OFFSET SOMEWHAT BY STRONG LARGE SCALE ASCENT AND MIDLEVEL
   COOLING...RELATED TO NW-FLOW SHORTWAVE TROUGH. AFTER
   DARK...SEPARATE AREA OF CONVECTION MAY DEVELOP AS LOW LEVEL
   WAA/ISENTROPIC ASCENT INTENSIFIES OVER SRN MN...IA AND PERHAPS NERN
   NEB.  SEVERE POTENTIAL WILL BE LIMITED BY RELATIVELY SMALL ELEVATED
   MUCAPES OF UNDER 700 J/KG...HOWEVER STRONGER CELLS MAY PRODUCE HAIL.
   
   
   ...MT...
   STEEP LOW-MIDLEVEL LAPSE RATES...DIURNAL HEATING OF HIGHER
   TERRAIN...AND MARGINAL LOW LEVEL MOISTURE WILL CONTRIBUTE TO
   CONNECTIVE DEVELOPMENT MID-LATE AFTERNOON.  TSTM COVERAGE SHOULD BE
   ISOLATED TO WIDELY SCATTERED...WITH A FEW CELLS PRODUCING HAIL/GUSTS
   NEAR SEVERE LEVELS.  MLCAPE IS EXPECTED TO INCREASE FROM 200-500
   J/KG RANGE OVER ROCKIES TO AROUND 500-800 K/KG ON HIGH PLAINS. 
   VERTICAL SHEAR WILL BE LIMITED BY WEAK LOW LEVEL FLOW AND LACK OF
   VEERING WITH HEIGHT IN MOST AREAS...EXCEPT NEAR WRN PORTION OF
   SECONDARY COLD FRONT THAT SHOULD MOVE SWWD THROUGH AREA.
   
   ..EDWARDS.. 06/23/2004
   
   ...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