SPC AC 230808
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0208 AM CST MON FEB 23 2015
VALID 251200Z - 261200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
CONSIDERABLE THUNDERSTORM ACTIVITY APPEARS POSSIBLE WEDNESDAY
THROUGH WEDNESDAY NIGHT...DEVELOPING NEAR THE NORTHEASTERN GULF
COAST...BEFORE SPREADING EAST NORTHEASTWARD ACROSS THE SOUTH
ATLANTIC COAST REGION.
...SYNOPSIS/FORECAST...
MODELS SUGGEST THAT BELTS OF WESTERLIES EMANATING FROM THE
MID-LATITUDE PACIFIC AND THE NORTH AMERICAN ARCTIC REGION WILL
CONTINUE TO CONVERGE INTO BROAD CYCLONIC FLOW ACROSS MUCH OF NORTH
AMERICA DURING THIS PERIOD. BENEATH THIS REGIME...ANOTHER EXPANSIVE
COLD SURFACE RIDGE APPEARS LIKELY TO BUILD AND BEGIN DEVELOPING
SOUTHWARD ACROSS THE CANADIAN/U.S. BORDER TO THE LEE OF THE ROCKIES.
IN ADVANCE OF THIS FEATURE...LOW-AMPLITUDE WAVE DEVELOPMENT IS
FORECAST TO OCCUR ALONG THE STALLING FRONTAL ZONE ACROSS THE
NORTHEASTERN GULF OF MEXICO INTO THE WATERS OFF THE SOUTH ATLANTIC
COAST. THIS IS EXPECTED TO OCCUR IN RESPONSE TO FORCING ASSOCIATED
WITH A SHORT WAVE IMPULSE IN THE SOUTHERN STREAM...AS IT TURNS EAST
NORTHEAST OF THE SOUTHERN PLAINS. ALTHOUGH MODELS INDICATE THAT
THIS IMPULSE WILL LOSE AMPLITUDE AS IT RAPIDLY ACCELERATES THROUGH A
CONFLUENT REGIME...ACROSS THE SOUTH ATLANTIC COAST BY 12Z
THURSDAY...IT APPEARS LIKELY TO BE ACCOMPANIED BY A 100+ KT 500 MB
SPEED MAXIMUM. COINCIDENT WITH THE DEVELOPING FRONTAL WAVE...WEST
SOUTHWESTERLY 850 MB FLOW IS FORECAST TO STRENGTHEN TO 50-70+
KT...ALLOWING FOR A SUBSTANTIVE INLAND RETURN FLOW OF MOISTURE FROM
THE NORTHEAST GULF OF MEXICO THROUGH SOUTHERN ATLANTIC COASTAL
AREAS.
EVEN ACROSS PARTS OF THE NORTHERN FLORIDA PENINSULA...MOISTURE
RETURN WILL GENERALLY OCCUR ABOVE A RESIDUAL COOL/STABLE
SURFACE-BASED LAYER...WHICH WILL BE INCREASINGLY DEEP WITH
NORTHWESTWARD EXTENT ACROSS THE GULF AND SOUTH ATLANTIC COAST
STATES. IT DOES NOT APPEAR THAT MID-LEVEL LAPSE RATES WILL STEEPEN
SUFFICIENTLY TO SUPPORT MUCH BEYOND WEAK CAPE /BASED IN THE ELEVATED
MOIST LAYER/. HOWEVER...THIS STILL SHOULD PROMOTE CONSIDERABLE
CONVECTION...AND EMBEDDED THUNDERSTORMS...IN THE PRESENCE OF STRONG
LIFT ASSOCIATED WITH LOWER/MID TROPOSPHERIC WARM ADVECTION
OVERSPREADING EASTERN GULF COASTAL AND SOUTH ATLANTIC COASTAL AREAS.
..KERR.. 02/23/2015
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z
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