Mar 19, 2012 0600 UTC Day 1 Convective Outlook
Updated: Mon Mar 19 06:01:30 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120319 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120319 1200 UTC Day 1 Tornado Probabilities 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.
Probabilistic Damaging Wind Graphic
20120319 1200 UTC Day 1 Damaging Wind Probabilities 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.
Probabilistic Large Hail Graphic
20120319 1200 UTC Day 1 Large Hail Probabilities 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.
   SPC AC 190557
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1257 AM CDT MON MAR 19 2012
   
   VALID 191200Z - 201200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF CNTRL AND NERN TX
   INTO FAR SERN OK...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FOR MUCH OF THE SRN PLAINS NWD
   INTO THE MID MO RIVER VALLEY...
   
   ...SYNOPSIS...
   AN EXPANSIVE FULL LATITUDE UPPER TROUGH WILL OVERSPREAD THE SRN AND
   CNTRL PLAINS ON MONDAY WITH MERIDIONAL STYLE FLOW REGIME. SLY LOW
   LEVEL FLOW WILL PERSIST THROUGHOUT THE PERIOD AHEAD OF A COLD
   FRONT...RESULTING IN AMPLE MOISTURE AND INSTABILITY FOR WIDESPREAD
   THUNDERSTORMS FROM TX INTO MN AND WI. THIS FRONT IS FORECAST TO
   EXTEND FROM WRN/CNTRL OK INTO WRN N TX EARLY MON...BUT SHOULD STALL
   ACROSS CNTRL TX. 
   
   MULTIPLE EPISODES OF SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE
   SRN PLAINS...AND THERE IS A WIDE VARIETY OF MODEL SOLUTIONS.
   HOWEVER...IT APPEARS CONSENSUS IS FOR WIDESPREAD SEVERE STORMS
   CENTERED OVER THE MDT RISK AREA...FROM CNTRL/NERN TX INTO SERN OK.
   
   ELSEWHERE...A WEAK DISTURBANCE IS FORECAST TO REMAIN OVER
   OH/PA/WV...WITH ISOLATED HAIL OR WIND POSSIBLE FROM DIURNALLY DRIVEN
   STORMS.
   
   ...TX INTO OK AND THE ARKLATEX REGION...
   A COMPLICATED CONVECTIVE DAY WILL UNFOLD ON MONDAY. UNCERTAINTIES
   BEGIN EARLY IN THE MORNING IN RELATION TO WHERE A SQUALL LINE...NOW
   OVER WRN TX...WILL BE LOCATED...AND HOW MUCH COLD POOL AND
   STABILIZATION WILL OCCUR WITH THIS SYSTEM. MODELS GENERALLY SUGGEST
   THIS LINE WILL BE OVER W CNTRL OK INTO WRN N TX AT 12Z...WITH SRN
   END NEAR I-20. THIS ACTIVITY WILL BE IN A STRONGLY SHEARED
   ENVIRONMENT...AND STRONG TO SEVERE WINDS WILL BE POSSIBLE IN
   ADDITION TO SOME HAIL. THIS ACTIVITY MAY REJUVENATE OVER ERN OK/NERN
   TX WITH A STRONG 50 KT LOW LEVEL JET FEEDING INTO THAT AREA. LATER
   IN THE AFTERNOON IN THIS SAME GENERAL VICINITY...ADDITIONAL
   DEVELOPMENT FUELED BY WARM ADVECTION MAY OCCUR WITH CONVECTION
   ALLOWING MODELS DEPICTING ISOLATED SUPERCELLS. SHEAR WOULD FAVOR
   DAMAGING WINDS AND A FEW TORNADOES.
   
   THE GREATEST SEVERE THREAT SHOULD BE DURING THE AFTERNOON AND INTO
   THE EVENING OVER MUCH OF CNTRL TX. AS OF THIS WRITING...THIS AREA
   SHOULD BE S OF THE MORNING ACTIVITY...AND ON THE INTERFACE OF STRONG
   HEATING PROGGED OVER WRN/W CNTRL TX. FORECAST SOUNDINGS SHOW STEEP
   LAPSE RATES ALOFT...STRONG INSTABILITY...AND AMPLE DEEP LAYER SHEAR
   FOR SIGNIFICANT SEVERE WEATHER INCLUDING VERY LARGE HAIL...DAMAGING
   WINDS AND TORNADOES. ISOLATED STRONG TORNADOES MAY OCCUR...BUT WILL
   DEFER POSSIBLE SIGNIFICANT TORNADO PROBABILITIES TO LATER OUTLOOKS
   GIVEN UNCERTAINTIES WITH LOW LEVEL FLOW AND BOUNDARY LOCATIONS.
   
   CONVECTIVE COVERAGE WILL ONLY INCREASE OVERNIGHT WITH COUPLED JET
   STRUCTURE ALOFT LIKELY RESULTING IN A LARGE MCS WITH SEVERE WEATHER
   AND FLOODING RAIN.
   
   ...ERN KS...MO...NEB/IA...
   UPPER 50S TO LOWER 60S F DEWPOINTS WILL STREAM NWD INTO THE MID MO
   VALLEY WITH A 40+ KT SLY LOW LEVEL JET. LITTLE CIN WILL EXIST SO
   WARM ADVECTION WILL BE SUFFICIENT TO DRIVE THUNDERSTORM DEVELOPMENT.
   THIS WILL OCCUR IN A STRONGLY SHEARED ENVIRONMENT...AND SOME STORMS
   MAY ACQUIRE ROTATION. A BRIEF TORNADO CANNOT BE RULED OUT...ALONG
   WITH GUSTY WINDS.
   
   ...OH/WV INTO THE MID ATLANTIC REGION...
   STRONG HEATING WILL OCCUR OVER THE REGION UNDER THE UPPER
   RIDGE...BUT A POCKET OF MOISTURE ASSOCIATED WITH THE WEAK UPPER
   WAVE/OLD MCV SHOULD HELP TO FOCUS SCATTERED THUNDERSTORMS DURING THE
   DAY. ALTHOUGH SHEAR WILL BE WEAK...NWLY FLOW ALOFT AND STEEP LAPSE
   RATES WILL FAVOR A FEW STORM CORES CAPABLE OF HAIL AND GUSTY WINDS.
   
   ..JEWELL/HURLBUT.. 03/19/2012
   
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