Thursday, May 10, 2007

DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 101704
SWODY2
SPC AC 101703

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1203 PM CDT THU MAY 10 2007

VALID 111200Z - 121200Z

..NO SVR TSTM AREAS FORECAST...

..SYNOPSIS...

PRIMARY BELT OF WESTERLIES WILL BE MAINTAINED ACROSS THE NRN TIER OF
STATES AND CANADA THROUGH THE DAY TWO PERIOD...TO THE N OF
AMPLIFYING RIDGE-TROUGH CONFIGURATION FROM THE CNTRL/SRN ROCKIES EWD
THROUGH SERN STATES. IN THE LOW-LEVELS...COLD FRONT WILL PUSH EWD
THROUGH NEW ENGLAND AND MID ATLANTIC STATES...WHILE THE WRN
EXTENSION OF THIS BOUNDARY BECOMES BETTER DEFINED WITH TIME FROM THE
MID MO VALLEY INTO NRN ROCKIES.

..CNTRL/ERN SD...

UNCERTAINTY EXISTS WITH REGARD TO WHETHER DIURNAL STORM DEVELOPMENT
WILL OCCUR ALONG LOW-LEVEL FRONTAL ZONE FRIDAY AFTERNOON/EVENING AS
MID-LEVEL HEIGHTS AND RESULTANT CAPPING ARE FORECAST TO INCREASE ON
NERN PERIPHERY OF BUILDING UPPER RIDGE. LOW-LEVEL MOISTURE IS
EXPECTED TO REMAIN MARGINAL ALONG/S OF BOUNDARY WITH DEWPOINTS
LIKELY REMAINING IN THE LOW/MID 50S. HOWEVER...STEEP LOW/MID-LEVEL
LAPSE RATES WILL EXIST...LARGELY CONTRIBUTING TO MLCAPES OF AROUND
1000 J/KG.

MID-LEVEL WNWLY FLOW WILL STRENGTHEN THROUGH THE DAY...INCREASING
TO 40-50 KT ACROSS FRONTAL ZONE WITH SUFFICIENT DEEP LAYER VERTICAL
SHEAR DEVELOPING FOR UPDRAFT ORGANIZATION/ROTATION. CURRENTLY...IT
APPEARS THAT MAJORITY OF WARM SECTOR WILL REMAIN CAPPED FOR
SURFACE-BASED STORM DEVELOPMENT THROUGH THE AFTERNOON AND EVENING.
SHOULD AN ISOLATED STORM OR TWO DEVELOP...ENVIRONMENT WILL BE
SUPPORTIVE FOR LOCALLY DAMAGING WINDS/HAIL. ATTM...THIS THREAT IS
TOO MARGINAL/ISOLATED TO WARRANT INCLUSION OF A CATEGORICAL SLIGHT
RISK.

..WRN MT...

ADDITIONAL STORMS ARE ALSO POSSIBLE LATE FRIDAY AFTERNOON INTO
EVENING ALONG WRN EXTENSION OF LOW-LEVEL FRONTAL BOUNDARY WHERE
OROGRAPHIC ASCENT WILL PROVIDE AN ADDITIONAL FOCUS FOR INITIATION IN
THE ABSENCE OF ANY SYNOPTIC SCALE FORCING. MOISTURE WILL BE
LIMITED...THOUGH STEEP LOW/MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO
WEAK CONVECTIVE INSTABILITY. MODERATELY STRONG DEEP LAYER VERTICAL
SHEAR WILL EXIST ACROSS THIS REGION AS WELL WITH ANY OF THE MORE
INTENSE STORMS CAPABLE OF ISOLATED...STRONG WIND GUSTS/HAIL.

..CNTRL GULF COAST INTO LOWER MS VALLEY...

A RELATIVELY MOIST LOW-LEVEL AIR MASS /DEWPOINTS IN THE MID 60S/
WILL EXIST ACROSS THE REGION FRIDAY BENEATH RATHER COOL MID-LEVEL
TEMPERATURES /-12 TO -14 C AT 500 MB/ ATTENDANT TO UPPER LOW
DRIFTING SEWD. THIS THERMAL/MOISTURE STRATIFICATION WILL RESULT IN
THE DEVELOPMENT OF A MODERATELY UNSTABLE AIR MASS /MLCAPES 2000-2500
J PER KG/ WITHIN A KINEMATIC ENVIRONMENT OF WEAK VERTICAL SHEAR.

WHILE STORMS SHOULD REMAIN RATHER DISORGANIZED...SOME POTENTIAL WILL
EXIST FOR A FEW STRONGER MULTICELL CLUSTERS CAPABLE OF WET
MICROBURSTS AND PERHAPS SOME MARGINALLY SEVERE HAIL.

.MEAD.. 05/10/2007

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