SPC AC 240734
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0234 AM CDT MON SEP 24 2007
VALID 261200Z - 271200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE
NORTHEAST...
...SYNOPSIS...
WHILE A SHORT-WAVE TROUGH CROSSES QUEBEC AND ONTARIO AND BRUSHES THE
NORTHEAST U.S. ON ITS WAY TO THE CANADIAN MARITIMES...LARGER-SCALE
TROUGH IS FORECAST TO SHIFT EWD ACROSS THE CENTRAL AND INTO THE ERN
CONUS WHILE SLOWLY AMPLIFYING. AT THE SURFACE...COLD FRONT SHOULD
CONTINUE STEADILY EWD ACROSS THE OH VALLEY AND INTO THE NORTHEAST
THROUGH THE AFTERNOON/EVENING.
...THE NORTHEAST...
THUNDERSTORMS SHOULD BE ONGOING ALONG/AHEAD OF THE ADVANCING COLD
FRONT ACROSS PARTS OF SRN QUEBEC/ONTARIO/THE GREAT LAKES/OH VALLEY
REGION AT THE START OF THE PERIOD...WITH STORMS AND THE ASSOCIATED
FRONT FORECAST TO SHIFT ACROSS THE NORTHEAST WITH TIME. WHILE
CLOUDS/PRECIPITATION SHOULD LIMIT HEATING...MARGINAL INSTABILITY
/AROUND 500 J/KG MIXED-LAYER CAPE/ IS FORECAST DURING THE AFTERNOON.
WITH 35 TO 45 KT FLOW THROUGH THE LOWER AND MID TROPOSPHERE FROM NY
NEWD...IT APPEARS THAT THE STORMS CROSSING THIS REGION WILL BE
ACCOMPANIED BY THE POTENTIAL FOR LOCALLY-DAMAGING WINDS -- PRIMARILY
DURING THE AFTERNOON AND EARLY EVENING HOURS.
...PARTS OF NM AND FAR W TX NEWD ACROSS THE TX AND OK PNHDLS...
LOW-LEVEL FLOW IS FORECAST TO TURN SLY ACROSS THIS REGION DURING THE
DAY...S OF A WEAK LOW FORECAST TO DEVELOP INVOF THE TX/OH
PANHANDLES. THIS IS EXPECTED TO OCCUR AS SRN FRINGE OF CENTRAL U.S.
TROUGHING/HEIGHT FALLS BRUSHES THIS REGION. DESPITE MODEST BOUNDARY
LAYER MOISTURE...DAYTIME HEATING AND RELATIVELY STEEP LAPSE RATES
SHOULD RESULT IN MARGINAL AIRMASS DESTABILIZATION. THIS SHOULD
SUPPORT ISOLATED STORM DEVELOPMENT DURING THE AFTERNOON INVOF THE
HIGHER TERRAIN OF NM -- AND PERHAPS ACROSS PARTS OF THE TX/OK
PANHANDLES NEAR THE WEAK SURFACE LOW. AN INCREASE IN CONVECTIVE
COVERAGE MAY OCCUR THROUGH THE EVENING ACROSS THIS PART OF THE AREA
IN CONJUNCTION WITH NOCTURNAL LOW-LEVEL JET DEVELOPMENT.
LOW-LEVEL SLY FLOW BENEATH 25 TO 35 KT WNWLY FLOW AT MID-LEVELS
SHOULD RESULT IN SUFFICIENT SHEAR FOR UPDRAFT ORGANIZATION. THUS --
GIVEN ISOLATED TO SCATTERED STORMS FORECAST ATTM...LOW-PROBABILITY
THREAT FOR HAIL AND LOCALLY-DAMAGING WINDS WILL BE INTRODUCED THIS
FORECAST.
..GOSS.. 09/24/2007
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z
|
