Mar 15, 2012 1300 UTC Day 1 Convective Outlook
Updated: Thu Mar 15 13:02:24 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120315 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120315 1300 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
20120315 1300 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
20120315 1300 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 151258
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0758 AM CDT THU MAR 15 2012
   
   VALID 151300Z - 161200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF AR/MO EAST TO
   THE TN/OH VALLEYS AND ERN GREAT LAKES...
   
   ...SYNOPSIS...
   RELATIVELY WEAK SWLY MID LEVEL FLOW EXISTS OVER MUCH OF THE U.S.
   THIS MORNING WITH STRONGER WINDS ALOFT CONFINED TO THE NORTHWEST/NRN
   PLAINS AND NRN NEW ENGLAND. ELSEWHERE...A BROAD BELT OF 10-30KT
   500MB FLOW EXTENDS FROM THE SOUTHWEST TO THE OH VALLEY ATOP SLIGHTLY
   STRONGER LOW LEVEL SWLY FLOW ON THE WRN FLANK OF ANTICYCLONE
   ANCHORED OVER THE SOUTHEAST AND ADJACENT ATLANTIC. MOST PRONOUNCED
   HEIGHT FALLS THIS PERIOD WILL OCCUR IN ASSOCIATION WITH A PACIFIC
   TROUGH SPREADING INLAND ACROSS WA/ORE. A LOW AMPLITUDE SHORT WAVE
   TROUGH EMBEDDED WITHIN THE WEAK FLOW ACROSS THE PLAINS...IN TANDEM
   WITH A SOMEWHAT STRONGER IMPULSE OVER CANADA...WILL RESULT IN WEAK
   HEIGHT FALLS SPREADING EAST FROM SRN PLAINS TO THE OH VALLEY/GREAT
   LAKES THROUGH TONIGHT.
   
   ...OZARKS TO OH/TN VALLEYS AND ERN GREAT LAKES...
   ANOMALOUSLY HIGH PW/MOISTURE AND MEAGER MID LEVEL FLOW/SHEAR WILL
   CONTINUE TO SUPPORT AN ATYPICAL SETUP FOR MID-MARCH TSTM DEVELOPMENT
   ACROSS AREAS FROM THE OZARKS ACROSS THE MID/LOWER MS VALLEY TO THE
   MIDWEST THROUGH TODAY. ONGOING STORMS FROM SRN IND TO OH/KY/WV AND
   ERN TN ARE IN RESPONSE TO MASS CONVERGENCE AND ISENTROPIC LIFT ON
   THE ERN EDGE OF EXTENSIVE CNTRL U.S. EML PLUME. RECENT TRENDS AND
   UPWIND PROPAGATION VECTORS SUGGEST THE MCS ROOTED ABOVE THE BOUNDARY
   LAYER IN OH/WV MAY PRODUCE LOCALLY HEAVY RAIN THIS MORNING. DESPITE
   THE LACK OF STRONGER VERTICAL SHEAR OVER THE AREA BASED ON MORNING
   SOUNDINGS AND OBJECTIVE ANALYSIS DATA SOME HAIL POTENTIAL WILL
   PERSIST DUE TO STEEP LAPSE RATES AND LOW FREEZING LEVELS.
   
   THE AFOREMENTIONED WEAK CIRCULATION/DISTURBANCE SPREADING EAST
   ACROSS THE SRN PLAINS THIS MORNING WILL BE ACCOMPANIED BY 10-30KT
   MID LEVEL FLOW PER LATEST PROFILER AND VWP OBSERVATIONS. LIFT
   ASSOCIATED WITH THIS IMPULSE WILL SPREAD EAST TOWARD THE MIDWEST AND
   MS VALLEY ATOP THE BROAD LOW LEVEL WARM/MOIST CONVEYOR BELT. POCKETS
   OF GREATER DIURNAL HEATING WILL CONTRIBUTE TO AREAS OF STRONG
   DESTABILIZATION OVER THE CNTRL AND SRN U.S. THIS AFTERNOON. MODEL
   GUIDANCE SUGGESTS THAT WEAKER INHIBITION EAST OF THE GREAT PLAINS
   SHOULD BE OVERCOME/ELIMINATED THROUGH A COMBINATION OF BACKGROUND
   ASCENT AND BOUNDARY LAYER DIABATIC HEATING/MIXING. MULTICELLULAR
   TSTM DEVELOPMENT IS EXPECTED IN THIS REGIME AND DESPITE LACK OF
   STRONGER DEEP-LAYER SHEAR THE THREAT FOR SCATTERED TO NUMEROUS HAIL
   AND GUSTY WIND EVENTS SEEMS POSSIBLE INTO THIS EVENING. IF GREATER
   STORM-SCALE ORGANIZATION CAN DEVELOP/EVOLVE THROUGH THE DAY IT MAY
   BE POSSIBLE TO PROVIDE A MORE DETAILED/FOCUSED TSTM WIND THREAT AREA
   BUT HAIL APPEARS TO BE THE PREDOMINANT SEVERE THREAT AT THIS TIME.
   
   WEAK FRONT WILL AID LIFT AMIDST INCREASINGLY UNSTABLE AIRMASS ACROSS
   LOWER MI AND OH LATER TODAY TO SUPPORT A FEW CLUSTERS/LINES OF
   STORMS ALSO CAPABLE OF PRODUCING HAIL AND GUSTY WINDS.
   
   ..CARBIN/SMITH/GUYER.. 03/15/2012
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z