DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 261739
SWODY2
SPC AC 261739

DAY 2 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
1239 PM CDT SAT MAY 26 2007

VALID 271200Z - 281200Z

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER OH
VALLEY...SRN NY AND NRN PA...

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL HIGH
PLAINS...

CORRECTED GEOGRAPHIC HEADLINE

..UPPER OH VALLEY/SRN NY/NRN PA...
AN UPPER LEVEL LOW OVER THE NRN PLAINS IS FORECAST TO DRIFT ENEWD
ACROSS ONTARIO TONIGHT INTO SUNDAY. AT THE SFC...A LOW OVER MN
TONIGHT WILL MOVE NWD AS A COLD FRONT MOVES SEWD ACROSS THE NRN OH
VALLEY ON SUNDAY. THUNDERSTORMS SHOULD BE ONGOING ALONG THE BOUNDARY
IN THE MORNING BUT THUNDERSTORM COVERAGE AND INTENSITY SHOULD
INCREASE SUNDAY AFTERNOON AS SFC TEMPS WARM. MCS DEVELOPMENT WILL BE
POSSIBLE ACROSS PARTS OF THE REGION LATE SUNDAY AFTERNOON INTO THE
EVENING.

CONCERNING THE SEVERE THREAT...MODEL FORECASTS MOVE AND STRENGTHEN A
60 KT MID-LEVEL JET EWD INTO THE GREAT LAKES TONIGHT INTO SUNDAY.
THE MID-LEVEL JET WILL CREATE MODERATE VERTICAL SHEAR PROFILES
ACROSS THE REGION SUNDAY WHICH SHOULD ALLOW FOR SCATTERED SEVERE
STORMS SUNDAY AFTERNOON. IF ENOUGH INSTABILITY DEVELOPS ALONG THE
MOIST AXIS...AN ISOLATED SUPERCELL THREAT COULD DEVELOP IN PARTS OF
THE REGION. IN ADDITION...FORECAST SOUNDINGS SHOW UNIDIRECTIONAL
WIND PROFILES AND COLD TEMPS ALOFT WHICH SHOULD SUPPORT AN ISOLATED
THREAT FOR HAIL AND WIND DAMAGE DURING THE LATE AFTERNOON. IF A
LINEAR MCS DEVELOPS AND PERSISTS INTO THE EVENING...A CONCENTRATED
SEVERE THREAT COULD EXIST ACROSS PARTS OF THE REGION.

..CNTRL HIGH PLAINS...
AN UPPER-LEVEL RIDGE IS FORECAST TO DEVELOP ACROSS THE FOUR CORNERS
REGION AND NRN HIGH PLAINS SUNDAY. ALTHOUGH SUBTLE...THE NAM AND GFS
ARE IN AGREEMENT MOVING A SHORTWAVE TROUGH EWD INTO THE CNTRL HIGH
PLAINS SUNDAY AFTERNOON. AT THE SFC...A MOISTURE AND INSTABILITY
AXIS SHOULD EXIST FROM WRN KS EXTENDING NNWWD INTO WRN NEB WITH
POCKETS OF MODERATE INSTABILITY BY LATE SUNDAY AFTERNOON. IN
ADDITION...FORECAST SOUNDINGS SHOW BACKED LOW-LEVEL WINDS WITH
MODERATE VERTICAL SHEAR PROFILES ASSOCIATED WITH THE SHORTWAVE
TROUGH. CONSIDERING VERY STEEP MID-LEVEL LAPSE RATES WILL BE IN
PLACE...THE INSTABILITY AND SHEAR SUGGESTS THAT THE ENVIRONMENT WILL
BE FAVORABLE FOR SEVERE STORMS LATE SUNDAY AFTERNOON. ALTHOUGH STORM
COVERAGE STILL REMAINS UNCERTAIN...ANY SUPERCELLS THAT DEVELOP
SHOULD HAVE A POTENTIAL FOR LARGE HAIL.

..NRN ROCKIES...
AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE INTO THE PACIFIC NW SUNDAY
WITH LARGE-SCALE ASCENT INCREASING ACROSS THE NRN ROCKIES SUNDAY
AFTERNOON. SFC HEATING AND THE LIFT SHOULD SUPPORT THE DEVELOPMENT
OF SCATTERED THUNDERSTORMS ACROSS THE REGION. ALTHOUGH LOW-LEVEL
MOISTURE WILL BE LIMITED...STRONG VERTICAL SHEAR PROFILES ASSOCIATED
WITH A MID-LEVEL JET MAY ALLOW SOME MARGINALLY SEVERE STORMS TO
DEVELOP AROUND PEAK HEATING.

.BROYLES.. 05/26/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.