SPC AC 310555
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT FRI JUL 31 2009
VALID 011200Z - 021200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS EASTERN OK/ARKLATEX...
...SYNOPSIS...
CENTERED OVER ONTARIO...A LONGWAVE TROUGH WILL CONTINUE TO DOMINATE
THE CONUS EAST OF THE ROCKIES...WHILE THE PRIMARY SYNOPTIC COLD
FRONT STEADILY ADVANCES EAST-SOUTHEASTWARD ACROSS THE GREAT LAKES
REGION/MIDWEST...AND SOUTHWARD ACROSS THE CENTRAL/SOUTHERN PLAINS.
OTHERWISE...GULF OF MEXICO/ROCKIES UPPER RIDGE WILL PREVAIL AHEAD OF
A SLOW MOVING/CLOSED UPPER LOW OFF THE NORTHERN CA COAST.
...SOUTHERN PLAINS/ARKLATEX VICINITY...
SHOWERS/TSTMS WILL LIKELY BE ONGOING SATURDAY MORNING ALONG/AHEAD OF
SOUTH-SOUTHEAST ADVANCING COLD FRONT...FROM PORTIONS OF THE LOWER MO
VALLEY INTO OK. PENDING THE TIMING OF THE FRONT AND DETAILS OF
ONGOING MORNING STORMS...IT APPEARS POCKETS OF STRONGER PREFRONTAL
HEATING AND A RESIDUALLY RATHER MOIST AIRMASS WILL FAVOR AN UPSWING
IN STRONGER TSTMS BY AFTERNOON. COINCIDENT WITH THE EXPECTED TIMING
OF THE PARENT MID LEVEL TROUGH/EARLY DAY STORMS...THE MOST ORGANIZED
SEVERE POTENTIAL SHOULD EXIST ACROSS PORTIONS OF EASTERN OK TO THE
ADJACENT ARKLATEX/MID-SOUTH. MEANWHILE...THE MOIST/UNSTABLE WARM
SECTOR FARTHER WEST ACROSS WEST/NORTH TX INTO PORTIONS OF OK WILL BE
CHARACTERIZED BY A RELATIVELY EARLY ONSET OF POST-WAVE SUBSIDENCE
AND RISING HEIGHTS/WARMING ALOFT...WHICH IS SUGGESTIVE OF A MORE
ISOLATED/CONDITIONAL SEVERE RISK ALONG THE FRONT. OVERALL...ON THE
SOUTHERN FRINGE OF THE STRONGER WESTERLIES...MODEST EFFECTIVE SHEAR
/GENERALLY 25-30 KT/ AND DOMINANCE OF LINEAR FORCING SUGGESTS
DAMAGING WINDS AND SOME HAIL WOULD BE THE PRIMARY HAZARDS.
...MIDWEST...
OPPORTUNITY FOR APPRECIABLE PRE-COLD FRONTAL DESTABILIZATION WILL
LIKELY BE MORE LIMITED WITH NORTHEASTWARD EXTENT ACROSS THE MIDDLE
MS VALLEY/LOWER OH VALLEY AND MIDWEST. NEVERTHELESS...AMPLE LARGE
SCALE/FRONTAL FORCING AND A WEST-SOUTHWESTERLY INSTABILITY FEED MAY
SUPPORT SOME STRONGER STORMS CAPABLE OF ISOLATED DAMAGING WINDS/HAIL
THROUGH EARLY SATURDAY EVENING.
...CAROLINAS...
THE PERSISTENCE OF BROAD CYCLONIC FLOW...ALONG WITH A RESIDUAL
SURFACE FRONT...COASTAL SEA BREEZE...AND/OR HEATING ALONG THE HIGHER
TERRAIN SHOULD AGAIN FAVOR STRONG STORMS CAPABLE OF DAMAGING
WINDS/PERHAPS SOME HAIL MAINLY SATURDAY AFTERNOON/EARLY EVENING.
...WESTERN ORE/NORTHERN CA...
SLIGHT EASTWARD SHIFT OF CLOSED OFFSHORE LOW SHOULD YIELD MODEST
HEIGHT FALLS/COOLING ALOFT...ALONG WITH AN INCREASE IN DEEP
SOUTHERLY FLOW...INTO THE WESTERN PORTIONS OF ORE/NORTHERN CA. AS
THE BOUNDARY LAYER DIURNALLY DESTABILIZES...A FEW STRONGER STORMS
CAPABLE OF SEVERE HAIL/WINDS WILL MAINLY BE POSSIBLE SATURDAY
AFTERNOON/EARLY EVENING.
..GUYER.. 07/31/2009
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
|
