SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT MON MAY 28 2012 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR THE NORTHEAST TO THE UPPER OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF THE CNTRL/SRN PLAINS TO THE OZARK PLATEAU... ...SYNOPSIS... LARGE-SCALE UPPER-LEVEL TROUGH CENTERED ALONG THE NRN PLAINS/CANADIAN PRAIRIES WILL SHIFT EWD ACROSS THE UPPER GREAT LAKES AND ONTARIO INTO WRN QUEBEC BY EARLY WED. AN UPSTREAM SHORT WAVE IMPULSE OFF THE PACIFIC NW SHOULD AMPLIFY AS IT REACHES THE LEE OF THE NRN ROCKIES. AT THE SURFACE...A COLD FRONT WILL MOVE EWD ACROSS THE LOWER GREAT LAKES TO OH VALLEY BY TUE AFTERNOON. TRAILING PORTION OF THIS BOUNDARY WILL ADVANCE NWD AS A WARM FRONT W OF THE OZARK PLATEAU ACROSS SRN KS. DRYLINE IS EXPECTED TO INTERSECT THE FRONT IN SWRN KS WITH N/S-ORIENTATION EXTENDING SWD ALONG THE TX PANHANDLE/WRN OK BORDER INTO WRN TX. ...NORTHEAST TO UPPER OH VALLEY... MODERATE MID-LEVEL HEIGHT FALLS WILL OCCUR OVER THE NORTHEAST STATES DURING THE DAY IN ADVANCE OF THE UPPER-LEVEL TROUGH CROSSING THE UPPER GREAT LAKES. A BROAD SWATH OF MODERATE TO STRONG MID-LEVEL SWLYS SHOULD EXIST FROM THE OH VALLEY NEWD ALONG/AHEAD OF AN ADVANCING COLD FRONT. MLCAPE VALUES OF 1500-2500 J/KG APPEAR PROBABLE BY EARLY AFTERNOON...SUPPORTING SCATTERED TO NUMEROUS TSTMS DEVELOPING THROUGH THE AFTERNOON. MODERATE LOW-LEVEL SWLYS SHOULD GENERALLY RESIDE FROM NY NEWD...WHICH SHOULD SUPPORT ORGANIZED UPDRAFTS CAPABLE OF LARGE HAIL AND DAMAGING WIND. FARTHER SW...THE SETUP SHOULD YIELD SEVERAL SUSTAINED MULTICELL CLUSTERS CAPABLE OF ISOLATED SEVERE HAIL/WIND. ...CNTRL/SRN PLAINS TO THE OZARK PLATEAU... DESPITE A NEBULOUS/LOW-AMPLITUDE UPPER-LEVEL PATTERN WITH BROAD MODERATELY STRONG W/NWLYS...A VERY UNSTABLE WARM/MOIST SECTOR WILL LIKELY DEVELOP BY PEAK HEATING. ALTHOUGH CONFIDENCE IN THE SPECIFIC SPATIAL/TEMPORAL DETAILS ARE NOT PARTICULARLY HIGH...MODEL GUIDANCE IS HIGHLY SUGGESTIVE OF SUSTAINED DEEP CONVECTIVE DEVELOPMENT TUE AFTERNOON/EVENING AS INTENSE HEATING MINIMIZES MLCIN. THIS APPEARS MOST PROBABLE ALONG THE DRYLINE FROM SWRN KS INTO NWRN TX...AND EWD ALONG THE WARM FRONT/LOW-LEVEL CONFLUENCE AXIS IN SRN KS. WITH MLCAPE PROBABLY REACHING 2500-4000 J/KG AMIDST 60S F SURFACE DEWPOINTS...VERY STEEP LAPSE RATES COINCIDENT WITH MODERATELY STRONG MID/HIGH-LEVEL WESTERLIES WILL SUPPORT SUPERCELLS CAPABLE OF VERY LARGE HAIL. GIVEN THE DEGREE OF BUOYANCY...MCS DEVELOPMENT APPEARS PROBABLE AS STORMS CONGEAL/ORGANIZE DURING THE EARLY EVENING HOURS...WITH A THREAT FOR SCATTERED SEVERE WIND/HAIL. IN SPITE OF FAVORABLE THERMODYNAMIC/KINEMATIC PROFILES FOR SUPERCELLS...THE TORNADO THREAT WILL BE HINDERED BY RELATIVELY WEAK LOW-LEVEL FLOW. ...LEE OF THE NRN ROCKIES... IN ASSOCIATION WITH THE APPROACHING SHORT WAVE IMPULSE...STRENGTHENING LARGE-SCALE ASCENT SHOULD AID IN SHOWER/TSTM DEVELOPMENT DURING THE LATE AFTERNOON/EARLY EVENING. BUOYANCY WILL LIKELY REMAIN QUITE LIMITED...BUT STEEP LAPSE RATES AMIDST 35-45 KT MID-LEVEL WLYS MAY BECOME SUFFICIENT FOR A MARGINAL SEVERE HAIL/WIND RISK. ..GRAMS.. 05/28/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day2otlk_1730.html
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