Thursday, April 5, 2012

DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 051730
SWODY2
SPC AC 051729

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT THU APR 05 2012

VALID 061200Z - 071200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
AN AMPLIFIED LONGWAVE PATTERN WILL PREVAIL OVER THE CONUS THROUGH
FRIDAY. TWO DISTINCT SPLIT BRANCHES OVER THE EASTERN THIRD OF THE
CONUS WILL PHASE ON FRIDAY WHILE THE LONGWAVE TROUGH OTHERWISE
SPREADS EASTWARD TO THE WESTERN ATLANTIC. MEANWHILE...THE BRUNT OF A
BROAD TROUGH OVER THE NORTHWEST CONUS/NORTHERN INTERMOUNTAIN REGION
TODAY WILL SPREAD NORTHEASTWARD AND REACH THE NORTHERN HIGH PLAINS
BY FRIDAY AFTERNOON/EVENING.

...SOUTHERN HIGH PLAINS...
SHORTWAVE RIDGING WILL ABATE ACROSS THE REGION INTO FRIDAY...BUT
LARGE SCALE FORCING FOR ASCENT WILL STILL BE NEBULOUS.
NONETHELESS...SUFFICIENT HEATING/CONVERGENCE IN VICINITY OF THE
DRYLINE SHOULD ALLOW FOR ISOLATED TSTMS TO DEVELOP BY LATE AFTERNOON
IN AREAS SUCH AS THE EASTERN TX PANHANDLE/CAPROCK VICINITY...AS WELL
AS PORTIONS OF SOUTHWEST TX INCLUDING THE PERMIAN BASIN. WHILE THE
BOUNDARY LAYER WILL NOT BE PARTICULARLY MOIST /GENERALLY LOWER 50S F
SURFACE DEWPOINTS OR LESS/ AND SUBJECT TO DEEP MIXING...HIGH-BASED
STORMS POTENTIALLY INCLUDING A FEW SUPERCELLS MAY BE CAPABLE OF
LARGE HAIL/GUSTY OUTFLOW WINDS DURING THE LATE AFTERNOON/EARLY
EVENING HOURS. WHILE LOCALLY SEVERE TSTMS WILL BE POSSIBLE...THE
OVERALL SEVERE EXTENT/MAGNITUDE SHOULD REMAIN TEMPERED GIVEN A
LIMITED MOISTURE/FORCING SCENARIO.

...NORTHERN HIGH PLAINS TO MIDDLE/LOWER MO RIVER VALLEY...
LARGE SCALE HEIGHT FALLS WILL STEADILY OCCUR ACROSS THE NORTHERN
PLAINS ON FRIDAY AS THE BRUNT OF THE SYNOPSIS-AFOREMENTIONED WESTERN
STATES TROUGH REACHES THE NORTHERN HIGH PLAINS. MOISTURE CONTENT
WILL REMAIN LIMITED ACROSS THE REGION /PW VALUES OF 0.6-0.8
INCHES/...BUT AMPLE FORCING FOR ASCENT AND SUFFICIENT MOISTURE WILL
LIKELY BE SUFFICIENT FOR ISOLATED TSTM DEVELOPMENT BY MID/LATE
AFTERNOON. SUCH SURFACE BASED TSTM DEVELOPMENT WILL BE MOST PROBABLE
IN VICINITY OF A NORTH-SOUTH ORIENTED HIGH PLAINS SURFACE TROUGH
AND/OR ALONG AN EASTWARD ADVANCING COLD FRONT /AS IT OVERTAKES THE
SURFACE TROUGH/. WHILE BUOYANCY WILL BE LIMITED /A COUPLE HUNDRED J
PER KG MLCAPE/...SOME OF THE STRONGER STORMS MAY PRODUCE WIND/HAIL
AS A LINEAR-TYPE ORGANIZATION WILL BE PROBABLE. A NOCTURNALLY
INCREASING LOW LEVEL JET/SOUTHEASTWARD ACCELERATING COLD FRONT
SHOULD FACILITATE A SOUTHEASTWARD-SPREAD OF TSTMS TOWARD THE
MIDDLE/LOWER MO VALLEY OVERNIGHT. WHILE INFLOW WILL BECOME
INCREASINGLY ELEVATED AFTER DARK WITHIN AN ALREADY LIMITED BUOYANCY
ENVIRONMENT...A MARGINAL HAIL/WIND RISK MAY PERSIST THROUGH LATE
FRIDAY/EARLY SATURDAY.

...FL PENINSULA...
WITHIN A MOIST/WEAKLY CAPPED AIRMASS AHEAD OF A COLD
FRONT...SCATTERED TSTMS /PERHAPS SOME STRONG OR SEVERE/ COULD LINGER
MAINLY ACROSS THE SOUTHERN HALF OF THE FL PENINSULA FRIDAY MORNING.
IN THE PRESENCE OF STRONG DEEP LAYER WEST-NORTHWESTERLY MID-HIGH
LEVEL FLOW...A SUPERCELL TORNADO THREAT MAY EXIST ASIDE FROM
ISOLATED WIND/HAIL. SUBSEQUENT REDEVELOPMENT/LONGEVITY OF THE SEVERE
THREAT IS MORE QUESTIONABLE INTO THE AFTERNOON AS BOUNDARY LAYER
WINDS CONTINUE TO VEER AND CONVERGENCE WEAKENS IN THE PRESENCE OF
INCREASING SUBSIDENCE ALOFT. HOWEVER...AT LEAST SOME SEVERE THREAT
COULD PERSIST INTO THE AFTERNOON FOR EASTERN COASTAL AREAS PRIOR TO
THE COLD FRONT CLEARING THE AREA.

..GUYER.. 04/05/2012

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