[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 200553
SWODY2
SPC AC 200552

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1252 AM CDT SAT AUG 20 2005

VALID 211200Z - 221200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM CZZ RAL TPH U31 WMC
10 SE MHS MFR DLS GEG 10 SE FCA GTF BIL REJ BUB BIE TOP 40 NNW SGF
CGI MVN 10 WSW SPI BMI FWA 35 ESE DTW.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 60 WSW COT 10 SE AUS
ACT ABI BGS FST 65 SW MRF.

...NO SVR TSTM AREAS FORECAST...

PHASING OF NORTHERN AND SOUTHERN BRANCH OF POLAR WESTERLIES AND
HIGH-LEVEL SUBTROPICAL WESTERLIES IS UNDERWAY NEAR THE CENTRAL
CANADIAN/U.S. BORDER.  CLOSED LOW HAS EVOLVED WITHIN LARGE UPPER
TROUGH...WHICH WILL PROGRESS THROUGH MUCH OF ONTARIO AND THE GREAT
LAKES REGION BY EARLY SUNDAY.  MODELS CONTINUE TO INDICATE
AMPLIFICATION AND SLOW SOUTHEASTWARD PROGRESSION OF UPPER TROUGH
WILL CONTINUE SUNDAY INTO EARLY MONDAY...SUPPRESSING SUBTROPICAL
RIDGING EAST OF THE MISSISSIPPI VALLEY.  THIS WILL BE ACCOMPANIED BY
SIGNIFICANT COOLING/DRYING THROUGH ALL BUT THE SOUTH ATLANTIC AND
GULF COAST STATES BY 12Z MONDAY.

IN WAKE OF EASTERN TROUGH...SPLIT HIGH-LEVEL FLOW REGIME WILL
PREVAIL FROM THE EASTERN PACIFIC INTO THE HIGH PLAINS. SHORT WAVE
RIDGE...DEVELOPING IN NORTHERN STREAM OVER THE NORTHERN ROCKIES
TODAY...WILL BEGIN TO DAMPEN...AS NEXT SHORT WAVE TROUGH BEGINS TO
MIGRATE INLAND OFF THE NORTHEAST PACIFIC.  MEANWHILE...WEAKER
SOUTHERN STREAM WILL BECOME INCREASINGLY ZONAL...EXTENDING ACROSS
CENTRAL CALIFORNIA AND THE FOUR CORNERS REGION INTO THE CENTRAL
PLAINS BY THE END OF THE FORECAST PERIOD.

...NORTHEAST...
MODELS CONTINUE TO SUGGEST MID-LEVEL WIND SHIFT/ASSOCIATED DRYING
WILL OVERSPREAD MID AND NORTH ATLANTIC COASTAL AREAS EARLY IN THE
PERIOD.  HOWEVER...STRONGER LOW-LEVEL COOLING IS NOT PROGGED
SOUTHEAST OF THE LOWER GREAT LAKES REGION UNTIL LATE SUNDAY/SUNDAY
NIGHT...IN ASSOCIATION WITH DIGGING SHORT WAVE EMBEDDED WITHIN
BROADER SCALE UPPER TROUGH.  

THUS...SUBSTANTIAL HEATING SEEMS LIKELY TO OCCUR IN THE LEE OF
APPALACHIANS... ALONG AN AXIS FROM CENTRAL/EASTERN MARYLAND INTO
SOUTHERN NEW ENGLAND.  WITH WEAK SOUTHERLY FLOW FORECAST TO MAINTAIN
MOIST BOUNDARY LAYER NEAR COASTAL AREAS...THIS IS EXPECTED TO
CONTRIBUTE TO DESTABILIZATION FROM THE DELMARVA PENINSULA THROUGH
NEW JERSEY INTO SOUTHERN NEW ENGLAND.  MIXED LAYER CAPE AS HIGH AS
2000+ J/KG APPEARS POSSIBLE BY PEAK HEATING...WHICH MAY PROVIDE
PRIMARY FORCING FOR CONVECTIVE DEVELOPMENT AS LARGE-SCALE FORCING
REMAINS RELATIVELY WEAK.  WITH AT LEAST WIDELY SCATTERED STORMS
POSSIBLE...MODERATE SOUTHWESTERLY MID-LEVEL FLOW WILL CONTRIBUTE TO
SUFFICIENT SHEAR FOR SHORT-LIVED UPDRAFT ROTATION AND SOME THREAT OF
GUSTY WINDS/HAIL IN STRONGEST CELLS.

OTHER SCATTERED STORMS WITH HAIL/GUSTY WINDS MAY ALSO DEVELOP ALONG
LEADING EDGE OF COLD CORE OF UPPER TROUGH...AS IT SPREADS EAST OF
THE LOWER GREAT LAKES REGION LATE SUNDAY AFTERNOON.  THIS ACTIVITY
IS EXPECTED TO DIMINISH FAIRLY RAPIDLY EARLY SUNDAY EVENING WITH
LOSS OF DAYTIME HEATING.

...NORTH CENTRAL HIGH PLAINS...
LOW-LEVEL THERMAL RIDGE SOUTH/WEST OF FRONTAL ZONE ASSOCIATED WITH
EASTERN TROUGH IS EXPECTED TO BECOME A FOCUS FOR WEAK TO MODERATE
DESTABILIZATION ACROSS PARTS OF SOUTHEAST WYOMING/SOUTHWEST
NEBRASKA/NORTHEAST COLORADO.  AIDED BY WEAK SUBTROPICAL STREAM
IMPULSE...SCATTERED CONVECTIVE DEVELOPMENT IS EXPECTED SUNDAY
AFTERNOON AND EVENING. THOUGH SHEAR PROFILES WILL BE WEAK...WARM
DEEP MIXED BOUNDARY LAYER MAY CONTRIBUTE TO A FAVORABLE
THERMODYNAMIC ENVIRONMENT FOR AN ISOLATED DOWNBURST OR TWO. 
MARGINALLY SEVERE HAIL WILL ALSO BE POSSIBLE.  AS LOW-LEVEL WARM
ADVECTION STRENGTHENS WITH DEVELOPMENT OF LOW-LEVEL JET SUNDAY
EVENING...STORMS COULD BE SLOW TO DIMINISH.  BUT...STABILIZATION OF
BOUNDARY LAYER WITH LOSS OF HEATING IS EXPECTED TO END LIMITED
SEVERE THREAT DURING THE EARLY EVENING HOURS.

...SOUTHERN TIER STATES...
PERTURBATIONS EMBEDDED WITHIN MOIST PLUME ON SOUTHERN FRINGE OF
SUBTROPICAL WESTERLIES...FROM THE SOUTHERN PLATEAU INTO BASE OF
EASTERN U.S. UPPER TROUGH...WILL CONTRIBUTE TO SCATTERED CLUSTERS OF
STORMS SUNDAY/SUNDAY NIGHT.  SUPPORTED PRIMARILY BY FAVORABLE
THERMODYNAMIC ENVIRONMENTS...STRONGEST STORMS MAY PRODUCE SOME HAIL
OR STRONG WIND GUSTS...BUT THESE EVENTS ARE EXPECTED TO REMAIN
FAIRLY MINOR OR HIGHLY LOCALIZED.

..KERR.. 08/20/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.