[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 021740
SWODY2
SPC AC 021739

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1239 PM CDT WED AUG 02 2006

VALID 031200Z - 041200Z

...THERE IS A SLGT RISK OF SVR TSTMS THROUGH EARLY THURSDAY NIGHT
FROM SRN NEW ENGLAND INTO THE LOWER OHIO VALLEY....

...SYNOPSIS...
MAIN BAND OF WESTERLIES WILL CONTINUE TO RUN ALONG THE NRN TIER OF
THE U.S. DURING THE PERIOD.  MINOR RAPIDLY MOVG MID LEVEL SHORTWAVE
TROUGH WILL MOVE EWD FROM THE UPR GREAT LAKES REGION INTO THE LWR
GREAT LAKES BY 04/00Z INTO THE CENTRAL NORTHEAST U.S. BY THE END OF
THE PERIOD.  THIS WILL PUSH MAIN COLD FRONTAL BOUNDARY SEWD
EXTENDING FROM LONG ISLAND/SERN NY STATE WSWWD THRU SWRN PA INTO E
CENTRAL MO BY EVENING. MEANWHILE...LARGE MID/UPPER LEVEL RIDGE WILL
PRETTY MUCH HOLD FROM THE CAROLINAS WWD THRU THE SRN PLAINS INTO THE
SRN ROCKIES.

...SRN PARTS OF NEW ENGLAND INTO THE LOWER OHIO VALLEY...

FRONTAL BOUNDARY/ASSOCIATED CONVECTIVE BOUNDARIES FROM PREVIOUS DAY
CONVECTION WILL EXTEND FROM SRN NH/VT WSWWD ALONG SRN PARTS OF THE
ERN GREAT LAKES AND CENTRAL IL INTO NWRN MO AT THE START OF THE
PERIOD.  NAM PUSHES SURFACE RIDGING INTO IA/IL DURING THE AFTN...BUT
ALSO LAGS 850 MB COLD FRONT ALONG THE SRN GREAT LAKES DURING THE
AFTN.  MID/UPR LEVEL JET STREAK OF 50-60 KT AND 80-90 KT
RESPECTIVELY WILL EXTEND FROM SERN ONTARIO ENEWD OVER NRN NEW
ENGLAND PLACING MUCH OF THE UPR OHIO VALLEY AND LOWER GREAT LAKES IN
FAVORABLE ENTRANCE REGION TO PROMOTE UPWARD ASCENT.  AIR MASS WILL
BE MOST UNSTABLE OVER SRN NEW ENGLAND INTO CENTRAL PA BY 03/18Z
WHERE THERE WILL BE DAYTIME HEATING WITH SBCAPES BETWEEN 2500-3000
J/KG.  

NAM IS QUESTIONABLE WITH LOW/MID LEVEL LAPSE RATES IN THESE AREAS
AND THAT COULD BE THAT 500 MB ARE AROUND -5C...BUT GIVEN THAT
SFC-3KM LAPSE RATES ARE 8.5C/KM AND DCAPE ESTIMATES ARE AROUND 1000
J/KG...IT LOOKS LIKE THE MAIN THREAT FOR DAMAGING WINDS WILL BE WITH
STORMS ALONG/AHEAD OF THE FRONT BY 03/18Z INTO THE 04/00Z TIME
FRAME...THEN DURING THE AFTN/EVE FROM WRN PA INTO E CENTRAL MO.

...SRN HIGH PLAINS...

STRONG DAYTIME HEATING IN VICINITY OF WEAKENING FRONTAL BOUNDARY
WILL BE SUFFICIENT FOR HIGH BASED TYPE THUNDERSTORMS FROM W CENTRAL
MO WSWWD INTO THE TX PANHANDLE.  MODEL SOUNDINGS INDICATE INVERTED-V
TYPE PROFILES ACROSS THESE AREAS WITH TEMP/DEW POINT DIFFERENCES
25-30 DEG F WITH LOW LEVEL LAPSE RATES NEAR 9C/KM.  THUS...STRONG
MICROBURSTS ARE EXPECTED WITH SCATTERED THUNDERSTORMS ACROSS THESE
AREAS LATE IN THE AFTN AND EVENING.

...PARTS OF THE CENTRAL AND NRN HIGH PLAINS...

MODELS WANT TO BRING SOME RETURN LOW LEVEL MOISTURE/UPSLOPE TYPE
FLOW INTO NERN CO NWD INTO THE BLACK HILLS OF SD.  EXPECT A FEW HIGH
BASED TYPE THUNDERSTORMS HERE AS WELL WITH LAPSE RATES AROUND 9C/KM
IN THE LOW LEVELS SUPPORTING THE POSSIBILITY OF DRY MICROBURSTS.

..MCCARTHY.. 08/02/2006