Feb 24, 2014 1300 UTC Day 1 Convective Outlook | |||||||||
Updated: Mon Feb 24 12:36:32 UTC 2014 ( | ) | |||||||||
Probabilistic to Categorical Outlook Conversion Table |
Categorical Graphic | |||||||||
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Probabilistic Tornado Graphic | |||||||||
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. |
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Probabilistic Damaging Wind Graphic | |||||||||
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point. |
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Probabilistic Large Hail Graphic | |||||||||
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point. |
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SPC AC 241233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 AM CST MON FEB 24 2014 VALID 241300Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER-AIR PATTERN WILL BE CHARACTERIZED BY PERSISTENT/BROAD CYCLONIC FLOW OVER MUCH OF CENTRAL/ERN CONUS. STG UPPER-LEVEL CYCLONE -- NOW EVIDENT IN MOISTURE-CHANNEL IMAGERY OVER NERN PAC AND CENTERED INVOF 38N148W -- IS FCST TO EJECT NEWD...AS DOWNSTREAM RIDGE AMPLIFIES FROM NWRN MEX UP W COAST STATES AND BC/YUKON. PRIMARY SHORTWAVE TROUGH -- CURRENTLY EVIDENT OVER SRN PORTIONS SK/MB BORDER WWD ACROSS SRN AB -- IS FCST TO MOVE SEWD ACROSS DAKOTAS BY 00Z THEN PIVOT/ACCELERATE EWD ACROSS WI TO LOWER MI BY END OF PERIOD. IN SRN STREAM...MOISTURE-CHANNEL LOOPS INDICATE WEAK PERTURBATION OVER SERN NM...W TX PERMIAN BASIN AND COAHUILA. THIS FEATURE IS RESOLVED TO SOME EXTENT BY 6Z OPERATIONAL NAM/SPECTRAL MODELS...WHICH PROG SRN PORTION TO MOVE ACROSS NRN GULF BETWEEN UPPER TX COAST AND FL COASTAL BEND DURING 00Z-12Z TIME FRAME. AT SFC...RESIDUAL/DIFFUSE AND QUASISTATIONARY FRONTAL ZONE WAS EVIDENT FROM S FL NWWD ACROSS NERN GULF THEN WWD ACROSS MOSTLY SHELF WATERS TO LOWER TX COAST. THAT FRONT WILL BE OVERTAKEN FROM W-E BY COLD FRONT NOW MOVING SEWD ACROSS GA...SRN AL...SRN LA AND S-CENTRAL TX. COMBINED FRONTAL ZONE SHOULD STALL ACROSS NWRN GULF AND S TX...RETURNING NWD AS WARM FRONT OVERNIGHT OVER TX. ...CENTRAL/ERN FL PENINSULA... WIDELY SCATTERED TSTMS MAY DEVELOP THIS AFTN ALONG SEA-BREEZE/CONVERGENCE ZONE OVER ERN PENINSULA...BENEATH DEEP-LAYER WLYS...AND AFTER PASSAGE OF CLOUD DEBRIS FROM MORNING ACTIVITY OVER GULF. ALTHOUGH E-COAST CONVERGENCE ZONE SHOULD CONCENTRATE BULK OF CONVECTIVE POTENTIAL...FRONT AND/OR OUTFLOW/DIFFERENTIAL-HEATING BOUNDARIES FROM EARLY CONVECTION ALSO MIGHT FOSTER SECONDARY TSTM INITIATION. FCST SOUNDINGS SUGGEST DIABATIC SFC HEATING AND MID-60S TO LOW-70S F SFC DEW POINTS WILL BE SUFFICIENT TO YIELD AROUND 1000-1500 J/KG MLCAPE ALONG I-95 CORRIDOR IN CENTRAL FL...BUT WITH MORE PRONOUNCED AND POTENTIALLY BUOYANCY-LIMITING MIDLEVEL STABLE LAYER FARTHER S. WEAK NEAR-SFC WIND SPEEDS WILL KEEP BOUNDARY-LAYER HODOGRAPHS SMALL...HOWEVER CONCENTRATIONS OF VORTICITY ALONG CONVERGENCE LINE MAY BRIEFLY SUPPORT STORM ROTATION. MULTICELLS SHOULD BE PREDOMINANT MODE...SOME OF WHICH MAY BECOME ORGANIZED AMIDST 70-KT ANVIL-LEVEL FLOW AND 30-40 KT EFFECTIVE SHEAR MAGNITUDES. FCST SOUNDINGS REASONABLY SUGGEST SHALLOW INVERTED-V THERMODYNAMIC PROFILES IN BOUNDARY LAYER AND SEASONALLY COLD AIR ALOFT -- E.G. -10 TO -12 C AT 500 MB. GIVEN THESE CONDITIONS...ISOLATED/MRGLLY SVR HAIL AND/OR ISOLATED DAMAGING GUSTS MAY OCCUR. ...N TX...RED RIVER REGION TO ARKLATEX... ISOLATED TO WIDELY SCATTERED ELEVATED TSTMS MAY DEVELOP LATE OVERNIGHT -- E.G. INITIALLY AFTER 06Z AND MOSTLY AFTER 09Z -- IN ZONE OF ELEVATED LOW-LEVEL WAA AND MRGL MOISTURE. UPPER-LEVEL SUPPORT WILL BE MINIMAL BY THAT TIME...WITH SRN-STREAM PERTURBATION WELL E OF AREA AND NO SUBSTANTIAL FEATURES EVIDENT UPSTREAM. HOWEVER...PLANAR PROGS AND TIME SERIES OF FCST SOUNDINGS SUGGEST GRADUAL INCREASE IN BOTH THETAE AND RH OF AIR MASS AROUND 850 MB OVERNIGHT. MINIMALLY INHIBITED MUCAPE OF 300-700 J/KG SHOULD DEVELOP BY 09-12Z TIME FRAME...ROOTED AROUND 850 MB...WITH CONVECTION SUPPORTED BY ISENTROPIC LIFT TO LFC. DEEP SHEAR AND BUOYANCY EACH APPEAR TOO MODEST FOR SVR THREAT. ...S TX... ISOLATED TO WIDELY SCATTERED TSTMS MAY SPREAD ENEWD FROM NUEVO LEON AND/OR REDEVELOP TODAY AHEAD OF MEXICAN LOBE OF AFOREMENTIONED SHORTWAVE TROUGH...AFFECTING PORTIONS S TX. WEAKENING OF INITIALLY ROBUST EML-RELATED CINH IS EVIDENT WITH SWD EXTENT AND WITH TIME TODAY ACROSS S TX...ALONG WITH UPPER 60S TO LOW 70S F SFC DEW POINTS AND POCKETS OF STG SFC HEATING MAINLY AHEAD OF FRONT. ALTHOUGH NLY COMPONENT OF PREFRONTAL FLOW WILL LIMIT CONVERGENCE...SOME FRONTAL LIFT MAY COMBINE WITH SFC HEATING IN SUPPORTING UPDRAFT DEVELOPMENT. ISOLATED TSTMS ALSO MAY DEVELOP BEHIND FRONT. OVERALL COVERAGE SHOULD BE LIMITED BY LACK OF MORE ROBUST LIFT AGAINST ANTECEDENT EML CINH. ..EDWARDS/BOTHWELL.. 02/24/2014 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z |