Apr 14, 2011 0600 UTC Day 2 Convective Outlook
Updated: Thu Apr 14 06:03:05 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110414 0600 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20110414 0600 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 140559
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1259 AM CDT THU APR 14 2011
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL GULF
   COAST STATES AND TN VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER TO
   MID-MS VALLEY...CNTRL TO ERN GULF COAST STATES...SRN APPALACHIAN
   MTNS AND OH VALLEY...
   
   ...TORNADO OUTBREAK BECOMING INCREASINGLY POSSIBLE ACROSS THE CNTRL
   GULF COAST STATES ON FRIDAY INTO FRIDAY NIGHT...
   
   ...CNTRL GULF COAST STATES/SRN APPALACHIAN MTNS...
   AN IMPRESSIVE NEGATIVELY-TILTED UPPER-LEVEL LOW IS FORECAST TO MOVE
   FROM THE CNTRL PLAINS EWD INTO THE OZARKS. THE EXIT REGION OF A 75
   TO 90 KT MID-LEVEL JET ROUNDING THE BASE OF THE UPPER-LEVEL TROUGH
   WILL OVERSPREAD THE CNTRL GULF STATES FRIDAY AFTERNOON CREATING VERY
   FAVORABLE DEEP LAYER SHEAR PROFILES FOR SEVERE STORMS OVER A BROAD
   AREA. AT THE SFC...A LOW WILL DEEPEN AND MOVE NEWD ACROSS THE OH
   VALLEY AS A TRAILING COLD FRONT ADVANCES EWD ACROSS THE MS VALLEY.
   ELEVATED THUNDERSTORM ACTIVITY MAY BE ONGOING ACROSS THE WARM SECTOR
   FRIDAY MORNING IN AL AND MIDDLE TN WITH THIS CONVECTION BEING
   SHUNTED EWD AWAY FROM THE MODERATE RISK AREA AROUND MIDDAY. AS THIS
   OCCURS...MODEL FORECASTS ARE CONSISTENT WITH DEVELOPING NUMEROUS
   THUNDERSTORMS ALONG THE WRN EDGE OF AN AXIS OF MODERATE TO STRONG
   INSTABILITY FROM WRN TN SWD ACROSS NRN AND CNTRL MS. THIS ACTIVITY
   SHOULD SPREAD EWD ACROSS THE MODERATE RISK AREA LATE FRIDAY
   AFTERNOON INTO THE EVENING.
   
   FORECAST SOUNDINGS ALONG THE INSTABILITY AXIS SHOW MLCAPE VALUES
   FROM 2000 TO 3000 J/KG IN CNTRL MS TO 1500 TO 2000 J/KG ACROSS WRN
   KY AND WRN TN. THIS IS COMBINED WITH 55 TO 70 KT OF DEEP LAYER SHEAR
   AND STRONG LOW-LEVEL SHEAR SHOULD RESULT IN SUPERCELL DEVELOPMENT
   WITH TORNADOES ACROSS THE MODERATE RISK AREA. 0-3 KM STORM RELATIVE
   HELICITIES ARE FORECAST TO BE 400 TO 500 M2/S2 WITH LOOPING
   HODOGRAPHS ACROSS MUCH OF ERN MS AND WRN AL SUGGESTING A POTENTIAL
   FOR LONG-TRACK STRONG TORNADOES WILL EXIST. 500 MB TEMPS ARE
   FORECAST TO BE FROM -12C IN SRN MS AND SRN AL TO -16C IN WRN TO
   MIDDLE TN. THIS ALONG WITH THE STRONG DEEP LAYER SHEAR SHOULD ALSO
   BE FAVORABLE FOR LARGE HAIL. VERY LARGE HAIL WILL BE POSSIBLE
   ESPECIALLY IN ERN MS AS SUPERCELLS DEVELOP DURING THE MID TO LATE
   AFTERNOON WHERE THE STRONGEST INSTABILITY IS FORECAST. ALTHOUGH
   DISCRETE CONVECTION IS ANTICIPATED EARLY IN THE EVENT...LINEAR
   DEVELOPMENT SHOULD INCREASE ALONG THE COLD FRONT BY EARLY EVENING
   WITH A SQUALL-LINE MOVING EWD ACROSS THE REGION. DISCRETE STORMS
   AHEAD OF THE LINE SHOULD CONTINUE TO HAVE TORNADO THREAT THROUGH THE
   EVENING.
   
   ONE CONCERN IS THAT THE LOW-LEVEL JET IS FORECAST TO BE MAXIMIZED
   OVER KY AND TN DURING THE EARLY EVENING. LOW-LEVEL SHEAR PROFILES
   WILL STILL BE VERY FAVORABLE FURTHER SOUTH IN MS AND AL BUT THE
   LOW-LEVEL JET RESPONSE MAY BE FOCUSED FURTHER TO THE NORTH. ANOTHER
   CONCERN IS FOR THE SRN EDGE OF THE MODERATE RISK. MODEL FORECASTS
   DIFFER ON CONVECTIVE COVERAGE WITH THE NAM ISOLATED BUT THE ECMWF
   DEVELOPS NUMEROUS STORMS. IN SPITE OF THE UNCERTAINTIES...WILL ISSUE
   A MODERATE RISK ACROSS MUCH OF THE CNTRL GULF COAST STATES DUE TO
   THE POTENTIAL FOR A HIGHER-END EVENT.
   
   ...MID-MS VALLEY/OH VALLEY...
   AN UPPER-LEVEL LOW WILL MOVE ACROSS THE OZARKS FRIDAY WITH A MOIST
   AXIS IN PLACE ACROSS KY...IL AND IND. THE DEVELOPMENT OF NUMEROUS
   SEVERE THUNDERSTORMS APPEARS LIKELY TO THE EAST OF THE UPPER-LEVEL
   LOW AS STRONG LARGE-SCALE ASCENT MOVES ACROSS THE REGION FRIDAY
   AFTERNOON. FORECAST SOUNDINGS ALONG THE MOIST AXIS SHOW SFC
   DEWPOINTS IN THE UPPER 50S F WITH DEEP LAYER SHEAR OF 40 TO 50 KT.
   THIS ENVIRONMENT ALONG WITH COLD TEMPS ALOFT SHOULD SUPPORT THE
   DEVELOPMENT OF SUPERCELLS WITH LARGE HAIL. BACKED SFC WINDS AND
   STRONG LOW-LEVEL SHEAR ALSO SHOULD BE FAVORABLE FOR A TORNADO THREAT
   WITH ROTATING STORMS. HOWEVER...STRONG LOW-LEVEL CONVERGENCE ALONG A
   COLD FRONT MAY FORCE A LINEAR MCS. THIS WOULD RESULT IN A WIDESPREAD
   WIND DAMAGE THREAT WITH THE LINE MOVING INTO IND...CNTRL KY AND
   ECNTRL TN DURING THE EVENING.
   
   ..BROYLES.. 04/14/2011
   
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