SPC AC 261730
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF EASTERN
OK/MUCH OF AR/SOUTHERN MO/SOUTHERN IL/FAR SOUTHWEST INDIANA/WESTERN
KY/WESTERN TN/NORTHERN MS...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
LOWER/MIDDLE MS VALLEY AND LOWER OH VALLEY...
...SYNOPSIS...
CLOSED UPPER LOW CURRENTLY CENTERED OVER CA IS EXPECTED TO
OPEN/SHIFT EASTWARD OVER AZ/NM DURING THE DAY ON SUNDAY...AND TAKE
ON MORE OF A NEUTRAL/SLIGHT NEGATIVE TILT AS IT REACHES THE SOUTHERN
PLAINS/OZARKS LATE SUNDAY NIGHT. A REGIONAL OUTBREAK OF SEVERE
TSTMS...INCLUDING THE POSSIBILITY OF WIDESPREAD DAMAGING
WINDS/STRONG TORNADOES...SEEMS PROBABLE LATE SUNDAY AFTERNOON AND
ESPECIALLY SUNDAY NIGHT.
...SOUTHERN PLAINS/ARKLATEX/OZARKS/MID-SOUTH/LOWER OH VALLEY...
THE POSSIBILITY OF WIDESPREAD DAMAGING WINDS AND TORNADOES
/INCLUDING SOME STRONG/...IN ADDITION TO AN INITIAL BOUT OF LARGE
HAIL...WILL BEGIN LATE SUNDAY AFTERNOON...AND CONTINUE WELL THROUGH
THE NIGHT/EARLY MORNING HOURS OF MONDAY ACROSS PORTIONS OF THE
OZARKS/MID-SOUTH TO MIDDLE MS VALLEY/LOWER OH VALLEY.
INITIAL/DIURNAL DEEP CONVECTIVE COVERAGE IS A STILL A BIT UNCERTAIN
ALONG THE DRYLINE ACROSS OK/NORTH TX/FAR SOUTHERN KS DURING THE
DAYLIGHT HOURS...AS MUCH OF THE WARM SECTOR SHOULD REMAIN CAPPED
BENEATH AN ELEVATED MIXED LAYER. NONETHELESS...CURRENT THINKING IS
THAT AT LEAST AN ISOLATED INITIAL THREAT FOR SEVERE TSTMS WILL
DEVELOP BY SUNSET...WITH INITIALLY ISOLATED SUPERCELLS CAPABLE OF
LARGE HAIL AND A TORNADO THREAT ACROSS PORTIONS OF OK/FAR NORTH TX
AND PERHAPS FAR SOUTHERN KS.
OTHERWISE...A SEASONALLY MOIST LOW LEVEL AIRMASS...GENERALLY
CHARACTERIZED BY LOWER 60S F SURFACE DEWPOINTS...WILL BECOME
ESTABLISHED WITHIN A RELATIVELY BROAD WARM SECTOR ACROSS THE REGION
DURING THE AFTERNOON/NIGHT. A CONSIDERABLE INCREASE IN DEEP
CONVECTIVE COVERAGE/INTENSITY IS ANTICIPATED THROUGH THE
EVENING...AS LARGE SCALE FORCING FOR ASCENT/DEEP TROPOSPHERIC WIND
FIELD DRAMATICALLY INCREASE ATTENDANT TO THE ADVANCING UPPER
TROUGH/POLAR JET. WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70
KT...SUFFICIENT INSTABILITY ON THE ORDER OF 750-1250 J/KG MLCAPE
WILL SUPPORT A POTENTIALLY WIDESPREAD SEVERE THREAT. GIVEN STRONG
LOW LEVEL SRH AS AIDED BY A STRENGTHENING 60+ KT LOW LEVEL JET...A
MIXED CONVECTIVE MODE INCLUDING QUASI-LINEAR BOWING
SEGMENTS/LINE-LEADING SEMI-DISCRETE SUPERCELLS WILL BE CAPABLE OF
WIDESPREAD DAMAGING WINDS/STRONG TORNADOES...AS THE SEVERE THREAT
CONTINUES WELL INTO THE EARLY MORNING HOURS OF MONDAY TOWARD THE
MIDDLE/LOWER MS AND TN/LOWER OH RIVER VALLEYS.
..GUYER.. 02/26/2011
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z
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