[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 311257
SWODY1
SPC AC 311255

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0755 AM CDT SAT JUL 31 2004

VALID 311300Z - 011200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 65 NNE
DVL STC 30 ENE MCW 40 NNW OTM P35 STJ BIE PIR 55 S GDV GDV ISN 70
NNE ISN.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM HUL
CON POU ABE CXY AOO 25 SSE DUJ ART 35 ENE MSS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM TYR DYR 25 W LUK 35 E
TOL FNT HTL MBL 30 NNW MMO COU LTS 25 SSW HOB 30 SSW INK SJT TYR
...CONT... 85 S GBN 20 SE PHX INW 75 NNE INW 55 WSW FMN 35 SSE MTJ
40 SSW CAG 40 NE VEL 50 NNE ENV 30 NNW WMC RBL 30 SE EKA 30 ESE CEC
45 WNW MFR EUG 55 NE BKE 60 E S80 35 E 3TH 65 ENE 63S.

...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL PA TO NRN NY AND NWRN
NEW ENGLAND....

...THERE IS A SLGT RISK OF SVR TSTMS NRN HIGH PLAINS TO ERN NEB/WRN
IA...

...SYNOPSIS...
SIGNIFICANT MID-UPPER LEVEL PATTERN EVOLUTION IS COMMENCING...TOWARD
MORE CLIMATOLOGICALLY TYPICAL MIDSUMMER REGIME.  4-CORNERS AREA HIGH
WILL CONTINUE TO STRENGTHEN...AS WILL RIDGE EXTENDING ESEWD ACROSS
WRN/CENTRAL GULF COAST STATES. HEIGHTS WILL RISE ACROSS MUCH OF
UPPER MIDWEST AND GREAT LAKES REGIONS TODAY AS STRONG SHORTWAVE
TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER LS -- WEAKENS
AND ACCELERATES NEWD ACROSS JAMES BAY REGION.  THIS WILL LEAVE
BEHIND A BROAD BELT OF WNWLY MID-UPPER LEVEL FLOW FROM SRN BC ESEWD
TO WI...AND 70-80 KT 250 MB SPEED MAX ALONG AND JUST N OF CANADIAN
BORDER.  MEANWHILE...NEARLY CUT-OFF UPPER LOW OFFSHORE CAPE
MENDOCINO WILL DRIFT ERRATICALLY THROUGH REMAINDER PERIOD.

AT SFC...LOW ANALYZED OVER ERN UPPER MI WITH WEAK COLD FRONT SWWD
ACROSS IA.  EXPECT BOTH LOW AND FRONT TO WEAKEN AS THEY MOVE
NEWD...AND AS [PARENT TROUGH EJECTS ACROSS JAMES BAY.  MAIN
CONVECTIVE FOCUS IN NERN STATES INSTEAD WILL BE CONVERGENCE BOUNDARY
ASSOCIATED WITH ONGOING CONVECTION FROM NY SWWD ACROSS ERN KY. 
FARTHER W...WEAK/BROAD AREA OF LOW PRESSURE IS ANALYZED OVER ERN
MT...CENTRAL/WRN SD AND WRN ND -- ALONG WITH TROUGH EXTENDING ESEWD
TOWARD SRN MN.

...NRN PLAINS...UPPER MIDWEST...
HEIGHT RISES ALOFT OF 30-60 M -- ALONG WITH NEWD ADVECTION OF
ELEVATED MIXED LAYER FROM HIGHER TERRAIN -- WILL CONTRIBUTE TO
STRENGTHENING CAPPING ACROSS MUCH OF THIS AREA.  THEREFORE THERE IS
SOME CONCERN THAT AFTERNOON CONVECTION MAY BE LIMITED OR ALTOGETHER
SUPPRESSED...DESPITE LARGE BUOYANCY RESULTING FROM INCREASING LAPSE
RATES AND SURFACE MOISTURE/HEATING.  ALTHOUGH CONVECTION MAY
INITIATE ALMOST ANYWHERE WITHIN CATEGORICAL OUTLOOK CORRIDOR...BEST
POTENTIAL ATM APPEARS TO BE OVER ERN SD/SWRN MN AREA WHERE CAP MAY
BE RELATIVELY WEAK.  MODIFIED RAOBS AND RUC SOUNDINGS INDICATE
MLCAPE WILL INCREASE FROM ABOUT 1000 J/KG WRN DAKOTAS TO 2500-3000
J/KG RANGE BETWEEN ABR AND NWRN IA.

ANY DIURNAL CONVECTION THAT DEVELOPS MAY TURN SSEWD AS SUPERCELLS
WITH POTENTIAL FOR DAMAGING WIND AND LARGE HAIL...BUT COVERAGE MAY
BE LIMITED BY CAPPING. AFTER DARK...ELEVATED LOW LEVEL WAA AND
MOIST ADVECTION WILL FURTHER DESTABILIZE AIR MASS JUST ABOVE
SFC...CONTRIBUTING TO ADDITIONAL TSTM DEVELOPMENT AND POTENTIAL FOR
AN MCS WITH SEVERE WIND/HAIL.  TSTMS MAY THEN PROPAGATE SEWD TO SWD
DOWN MO VALLEY OVERNIGHT.

...NERN CONUS...
BAND OF CONVECTION WITH SCATTERED TSTMS WILL INTENSIFY LATE MORNING
INTO AFTERNOON AS FOREGOING BOUNDARY LAYER DIABATICALLY HEATS...WITH
SFC DEW POINTS MID 60S TO LOW 70S F IN INFLOW AIR.  MAIN THREAT WILL
BE DAMAGING WIND FROM BOW/LEWP FORMATIONS.  LOW LCL AND RELATIVELY
LARGE VALUES OF LOW LEVEL SHEAR INDICATE THAT ANY SUSTAINED/DISCRETE
SUPERCELLS THAT DEVELOP MAY PRODUCE A TORNADO...BUT THIS IS A MORE
CONDITIONAL RISK THAN FOR DAMAGING WIND.

DEEP-TROPOSPHERIC SHEAR WILL INCREASE WITH NWD EXTENT WHILE MLCAPE
INCREASES SWD. MODIFIED RAOBS AND RUC FCST SOUNDINGS INDICATE SOME
COMBINATION OF BUOYANCY AND VERTICAL SHEAR WILL BECOME FAVORABLE FOR
ORGANIZED SEVERE DURING 15-18Z TIME FRAME OVER PORTIONS WRN NY AND
WRN PA...PROGRESSING EWD THROUGHOUT DAY.  EXPECT  150-300 J/KG 0-3
KM SRH AND 20-30 KT VECTOR SHEAR THROUGH LOWEST 2 KM. 
MEANWHILE...HEATING AND MOISTURE AT SFC WILL OVERCOME WEAKLY
UNSTABLE MIDLEVEL LAPSE RATES TO YIELD AROUND 1500 J/KG MLCAPE
CENTRAL PA...BECOMING LESS THAN 500 J/KG ALONG CANADIAN BORDER. 
SEVERE POTENTIAL IS EXPECTED TO DIMINISH MARKEDLY AFTER
APPROXIMATELY 00Z...WITH LOSS OF INSOLATION AND OF MOST OF REMAINING
SFC-BASED INSTABILITY.

..EDWARDS/GUYER.. 07/31/2004

...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.