Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS03 KWNS 270831
SWODY3
SPC AC 270830

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CST FRI FEB 27 2015

VALID 011200Z - 021200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS
COASTAL AREAS OF CENTRAL AND SOUTHERN CALIFORNIA.  SCATTERED
THUNDERSTORMS WILL BE POSSIBLE FROM PARTS OF EAST TEXAS TO THE
MID-SOUTH REGION OF NORTHERN MISSISSIPPI...EASTERN ARKANSAS...AND
SOUTHWEST TENNESSEE.

...SYNOPSIS...
IN THE LARGE SCALE...A BLOCKING RIDGE WILL REMAIN IN PLACE GENERALLY
WEST OF THE PACIFIC COAST...WHILE SPLIT BELTS OF DOWNSTREAM
WESTERLIES CONTINUE TO BE BROADLY CONFLUENT ALONG AND EAST OF THE
ROCKIES..  THIS LATTER FLOW REGIME WILL BE LOCATED BETWEEN A
PROMINENT SUBTROPICAL RIDGE OVER THE BAHAMAS/CARIBBEAN TO THE GULF
OF MEXICO AND A PERSISTENT NORTHEASTERN CANADIAN VORTEX.
A PROGRESSIVE NRN-STREAM SHORTWAVE TROUGH WILL TRACK EWD FROM THE
NRN PLAINS THROUGH THE GREAT LAKES REGION ON SUNDAY.  HEIGHTS WILL
RISE INTO THE FOUR CORNERS REGION AND ACROSS THE CENTRAL/NRN PLAINS
IN THE WAKE OF THE NRN STREAM TROUGH AND AS THE CA/NV TROUGH
DEVELOPS FARTHER SWD THROUGH SRN CA AND WEST OF NRN BAJA.

AT THE SURFACE...A COLD FRONT ATTENDANT TO THE NRN-STREAM TROUGH
WILL ADVANCE SWD THROUGH THE SRN PLAINS...MID MS VALLEY AND MID
SOUTH...AND INTO THE NERN STATES.  BY 12Z MONDAY...THIS BOUNDARY
SHOULD EXTEND FROM ERN NY THROUGH THE CENTRAL APPALACHIANS TO NRN
MS/LA TO CENTRAL TX.

...EAST TX/SERN OK/NRN LA/AR/NRN MS/SWRN TN...
S/SWLY LOW-LEVEL FLOW FROM THE WRN GULF OF MEXICO WILL SUPPORT
MOISTURE RETURN INVOF AN INVERTED TROUGH EXTENDING FROM THE MIDDLE
TX COAST THROUGH EAST TX INTO AR.  DESPITE WEAK FORCING ALOFT AND
WARM MIDLEVEL TEMPERATURES /PER FORECAST SOUNDINGS/ ATTENDANT TO THE
MID-UPPER-LEVEL RIDGING...SUFFICIENT LOW-LEVEL MOISTENING AND WAA
SUGGEST MAINLY ELEVATED TSTMS WILL BE POSSIBLE.  ISENTROPIC ASCENT
AND WAA WILL BE THE PRIMARY FORCING MECHANISMS.

...CENTRAL AND SRN CA COASTAL AREAS...
STEEP LAPSE RATES ATTENDANT TO THE COLD MIDLEVEL TROUGH ACROSS THIS
REGION SHOULD SUPPORT TSTM DEVELOPMENT AS THIS TROUGH SHIFTS SWD.

..PETERS.. 02/27/2015




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