[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 060544
SWODY2
SPC AC 060543

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1143 PM CST FRI JAN 05 2007

VALID 071200Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS LATE SUN AFTN/SUN NIGHT ACROSS
PARTS OF THE SRN MID ATLANTIC COAST STATES....

IMPULSES EMBEDDED WITHIN COMPLEX SPLIT UPPER FLOW PATTERN STILL
APPEAR LIKELY TO CONSOLIDATE INTO AN AMPLIFIED LARGE-SCALE TROUGH
ENCOMPASSING MUCH OF THE CENTRAL/EASTERN STATES BY THE END OF THIS
FORECAST PERIOD.  THE PRIMARY IMPULSE EXPECTED TO SUPPORT THIS
DEVELOPMENT IS READILY EVIDENT IN LATEST WATER VAPOR IMAGERY...
DIGGING ACROSS THE NORTHWESTERN U.S...WITHIN THE NORTHERN BRANCH OF
THE POLAR WESTERLIES.  THE COLD...VIGOROUS SHORT WAVE TROUGH IS
PROGGED TO CONTINUE TO DIG TO THE LEE OF THE ROCKIES...THROUGH THE
NORTHERN AND CENTRAL PLAINS BY MIDDAY SUNDAY...BEFORE TURNING
EASTWARD ACROSS THE UPPER HALF OF THE MISSISSIPPI VALLEY/THE OHIO
VALLEY AND GREAT LAKES REGION BY 12Z MONDAY.  AS THIS OCCURS...
MODELS INDICATE THAT THE LARGER SCALE TROUGH WILL TAKE ON AN
INCREASINGLY NEGATIVE TILT...ACCOMPANIED BY STRONG SURFACE
CYCLOGENESIS FROM THE LEE OF THE APPALACHIANS THROUGH THE NORTH
ATLANTIC COAST.

...SOUTHERN/MID ATLANTIC COAST STATES...
MODELS SUGGEST THAT MODIFICATION OF BOUNDARY LAYER OVER THE NORTH
CENTRAL GULF OF MEXICO...AND RETURN FLOW INTO THE SOUTHEASTERN
STATES...WILL BE RAPID IN THE WAKE OF A WEAKENING LEAD SOUTHERN
BRANCH SHORT WAVE TROUGH...NOW RAPIDLY LIFTING INTO/THROUGH THE
SOUTH ATLANTIC COAST REGION.  HOWEVER...COLDER AIR ALOFT...LAGGING
WELL TO THE NORTH/WEST...IS NOT PROGGED TO OVERSPREAD RETURNING
MOISTURE...AND LAPSE RATES WILL REMAIN WEAK IN EVOLVING WARM SECTOR
THROUGH THIS FORECAST PERIOD.  THIS WILL TEND TO MINIMIZE CAPE...AND
MAY TEMPER SEVERE POTENTIAL ACROSS THE SOUTHEAST SUNDAY/SUNDAY
NIGHT.

STILL...A RISK OF SEVERE STORMS IS SUPPORTED BY ANTICIPATED FORCING
FOR UPWARD VERTICAL MOTION ASSOCIATED WITH RAPID DEEPENING OF
SURFACE LOW...WHICH MODELS INDICATE WILL COMMENCE TO THE LEE OF THE
SOUTHERN APPALACHIANS SUNDAY EVENING.  THIS WILL BE ACCOMPANIED BY
STRENGTHENING LOW-LEVEL FLOW FIELDS...LIKELY INCLUDING A 50-70 KT
SOUTHERLY LOW-LEVEL JET FROM THE CAROLINAS THROUGH THE DELMARVA
PENINSULA BY LATE SUNDAY EVENING.  INFLUX OF MOISTENING BOUNDARY
LAYER OFF THE SOUTH ATLANTIC APPEARS LIKELY ACROSS AT LEAST THE
COASTAL PLAIN OF EASTERN NORTHERN CAROLINA...WHERE LOW-LEVEL
HODOGRAPHS TO THE EAST OF DEVELOPING CYCLONE WILL BE LARGE AND
FAVORABLE FOR ISOLATED SUPERCELLS WITH TORNADOES.

AS SURFACE LOW DEVELOPS INTO/OFF MID ATLANTIC COASTAL AREAS LATER
SUNDAY NIGHT...A CONVECTIVE BAND...ACCOMPANYING EASTWARD SURGING
COLD FRONT TO ITS SOUTH...COULD ENHANCE DOWNWARD MOMENTUM TRANSFER
ACROSS THE SOUTHERN MID ATLANTIC COAST.

..KERR.. 01/06/2007