SPC 0600Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT THU MAY 31 2012 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGE PART OF THE EASTERN STATES... ...MUCH OF THE EASTERN STATES... THE FIRST DAY OF JUNE WILL SEE THE EAST-NORTHEASTWARD ADVANCEMENT OF A POTENT UPPER TROUGH OVER THE EASTERN THIRD OF THE CONUS...WITH DEEP CONVECTIVE/SEVERE POTENTIAL FOCUSED ALONG/AHEAD OF AN EASTWARD MOVING COLD FRONT AS IT CROSSES THE APPALACHIANS FRIDAY MORNING/AFTERNOON. THE PARENT SYSTEM IS EXPECTED TO SLOWLY TREND TOWARD A SLIGHT NEGATIVE TILT ON FRIDAY...WITH A STEADILY STRENGTHENING BELT OF DEEP LAYER SOUTHWESTERLY FLOW OVERSPREADING MUCH OF THE CENTRAL APPALACHIANS AND MID-ATLANTIC/NORTHEAST STATES. ACCORDINGLY...AMPLE FORCING FOR ASCENT/VERTICAL SHEAR WILL CONTRIBUTE TO SUSTAINED STRONG/SEVERE TSTMS WITHIN A DIURNALLY DESTABILIZING BOUNDARY LAYER...WITH SUCH DEVELOPMENT FOCUSED IN VICINITY OF THE COLD FRONT OR PERHAPS A PRE-FRONTAL TROUGH. IT IS LIKELY THAT AMPLE PRE-FRONTAL INSOLATION WILL COINCIDE WITH AN INCREASINGLY MOIST BOUNDARY LAYER...SUCH THAT A BROAD AREA OF 1000-2000 J/KG MLCAPE SEEMS LIKELY FROM THE CAROLINAS TO THE DELMARVA/SOUTHERN PA...ALONG/SOUTH OF A NORTHWARD-SHIFTING WARM FRONT ACROSS THE MID-ATLANTIC STATES/DELMARVA. THAT SAID...LOCALLY STRONGER DESTABILIZATION WILL BE POSSIBLE ACROSS PARTS OF THE CAROLINAS/GA/NORTH FL ALBEIT WITHIN A WEAKER SHEAR REGIME. OVERALL...DAMAGING WINDS /POTENTIALLY WIDESPREAD AT THAT/ AND SEVERE HAIL WILL BE THE PRIMARY HAZARDS FROM WHAT SHOULD MAINLY BE A MULTICELLULAR/LINEAR CONVECTIVE MODE ACROSS THE MAJORITY OF THE SLIGHT RISK AREA. THAT SAID...SOME SUPERCELLS...INCLUDING A TORNADO THREAT...COULD OCCUR MAINLY ACROSS VA/DELMARVA REGION INTO SOUTHERN PA/NJ PROVIDED 1/ SUFFICIENT DESTABILIZATION OCCURS NEAR THE WARM FRONT AND 2/ SEMI-DISCRETE DEVELOPMENT OCCURS AHEAD OF THE COLD FRONT WHERE A LINEAR MODE SHOULD BE MORE DOMINANT. SOMEWHAT HIGHER PROBABILITIES/PERHAPS EVEN A CATEGORICAL MODERATE RISK MIGHT BE WARRANTED IN SUBSEQUENT CONVECTIVE OUTLOOKS. ...SOUTH-CENTRAL HIGH PLAINS... AMID RELATIVELY NEBULOUS NORTHWESTERLY FLOW ALOFT...ISOLATED TSTMS SHOULD DEVELOP AND PROPAGATE SOUTHEASTWARD NEAR/EAST OF A HIGH PLAINS SURFACE LOW/TROUGH FRIDAY AFTERNOON/EARLY EVENING. THIS INCLUDES A CORRIDOR ACROSS FAR SOUTHEAST CO/EASTERN NM AND THE OK/TX PANHANDLES AS FAR SOUTHWEST KS. MOISTURE CONTENT/BUOYANCY WILL BE MODEST...BUT ISOLATED STRONG/SEVERE TSTMS CAPABLE OF HAIL/PERHAPS GUSTY WINDS WILL BE POSSIBLE FRIDAY AFTERNOON/EARLY EVENING AT LEAST ON AN ISOLATED BASIS. A STRENGTHENING LOW LEVEL JET/WARM ADVECTION REGIME AFTER DARK MAY ALLOW FOR SUSTENANCE OF A FEW TSTM CLUSTERS...OR MORE SO A SEPARATE AREA OF LATE EVENING/OVERNIGHT TSTM DEVELOPMENT A BIT FARTHER EAST ACROSS SOUTHERN KS/NORTHERN OK. SOME HAIL MAY BE POSSIBLE. ...DAKOTAS/MIDDLE MO RIVER VALLEY... IN VICINITY OF A NORTH-SOUTH SURFACE TROUGH...ISOLATED/RELATIVELY LOW-TOPPED TSTMS SHOULD DEVELOP FRIDAY AFTERNOON IN ASSOCIATION WITH A FAST-MOVING/CLIPPER-TYPE SHORTWAVE TROUGH. LOW LEVEL MOISTURE WILL BE QUITE LIMITED /GENERALLY 40S F SURFACE DEWPOINTS/ GIVEN SHORT-TERM TRAJECTORIES. NONETHELESS...STEEP LAPSE RATES/WEAK CAPE IN THE PRESENCE OF AMPLE VERTICAL SHEAR COULD ALLOW FOR A FEW STRONGER STORMS CAPABLE OF MARGINAL HAIL AND/OR GUSTY WINDS. ...NORTHERN CA/NV TO ORE/NORTHERN INTERMOUNTAIN WEST... ISOLATED TSTMS SHOULD BECOME MORE PROBABLE ACROSS THE REGION BY FRIDAY AS AN UPPER TROUGH APPROACHES THE REGION/PW VALUES BEGIN TO INCREASE. A FEW STRONGER TSTMS WITH GUSTY WINDS/HAIL MIGHT BE POSSIBLE ON A VERY LOCALIZED BASIS...BUT SEVERE PROBABILITIES DO NOT APPEAR WARRANTED. ..GUYER.. 05/31/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day2otlk_0600.html
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