SPC AC 081729
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT FRI MAY 08 2009
VALID 091200Z - 101200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE
MID-ATLANTIC REGION/CAROLINAS...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE PORTIONS OF THE GULF
COAST STATES AND WWD INTO TX...
...SYNOPSIS...
BROAD UPPER CYCLONIC FLOW AT MID-LEVELS WILL PREVAIL ACROSS THE U.S.
THIS PERIOD...WITH A STRONGER/EMBEDDED SHORT-WAVE TROUGH FORECAST TO
CROSS THE LOWER GREAT LAKES REGION/NEW ENGLAND THROUGH THE PERIOD.
OTHERWISE...ENHANCED CYCLONIC/WLY FLOW WILL PREVAIL ACROSS MUCH OF
THE CONUS.
AT THE SURFACE...LOW PRESSURE IS FORECAST TO MOVE ENEWD ACROSS THE
LOWER LAKES/ST. LAWRENCE VALLEY REGION THROUGH THE PERIOD...WHILE AN
ASSOCIATED COLD FRONT MOVES ACROSS THE NORTHEAST...AND TRAILS WSWWD
ACROSS THE GULF COAST REGION AND INTO TX THROUGH THE PERIOD.
...THE MID-ATLANTIC REGION INTO THE CAROLINAS...
MODEST MOIST ADVECTION AHEAD OF A FAIRLY STRONG COLD FRONT CROSSING
THIS REGION WILL COMBINE WITH DAYTIME HEATING TO YIELD AIRMASS
DESTABILIZATION -- RANGING FROM NEAR 500 J/KG MIXED-LAYER CAPE
ACROSS SERN NY TO AROUND 1000 J/KG FARTHER S INTO DE/VA/MD/NC.
WHILE STRONGER UPPER FORCING IS FORECAST TO REMAIN FARTHER N --
ACROSS NRN NY AND NEW ENGLAND...HEIGHT FALLS ACROSS THIS REGION
COMBINED WITH STRONG CONVERGENCE ALONG THE COLD FRONT WILL RESULT IN
STORM DEVELOPMENT ALONG AND NEAR THE COLD FRONT DURING THE
AFTERNOON.
WHILE QUASI-UNIDIRECTIONAL...STRONG DEEP-LAYER WIND FIELD WILL
SUPPORT ORGANIZED/VIGOROUS STORMS...WITH A PRIMARILY LINEAR STORM
MODE ANTICIPATED. ALONG WITH MARGINAL HAIL...THE PRIMARY SEVERE
THREAT APPEARS TO BE DAMAGING WINDS ACROSS THIS REGION AS THE LINE
OF STORMS SHIFTS EWD TOWARD THE ATLANTIC COAST THROUGH THE AFTERNOON
AND EVENING.
...GULF COAST STATES INTO TX...
COLD FRONT WILL SLOWLY SAG SWD ACROSS THE GULF COAST STATES/TX THIS
PERIOD...WITH A MOIST/UNSTABLE BUT CAPPED AIRMASS FORECAST S OF THE
FRONT. WEAK LOW-LEVEL SLY FLOW SHOULD HOWEVER PROVIDE AMPLE
ISENTROPIC LIFT ATOP THE BOUNDARY TO SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS...FROM NORTHEAST TX/SERN OK EWD INTO GA/SC. WHILE WLY
FLOW ALOFT WILL NOT BE PARTICULARLY STRONG...SHEAR SHOULD BE
SUFFICIENT TO SUPPORT ORGANIZED/MULTICELL STORMS CAPABLE OF
PRODUCING LOCALLY GUSTY/DAMAGING WINDS AND MARGINAL HAIL. THREAT
WILL BE PRIMARILY DIURNAL...WITH SLOW WEAKENING OF THE CONVECTION
EXPECTED AFTER DARK ACROSS THE GULF COAST REGION. ELEVATED
CONVECTION MAY PERSIST WELL INTO THE OVERNIGHT HOURS ACROSS PARTS OF
TX...WHERE MODEST /NEAR 30 KT/ SLY LOW-LEVEL JET IS EXPECTED TO
DEVELOP.
..GOSS.. 05/08/2009
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z
|
