Stormchasers.co.uk

SPC Day 1 Outlook Text Only

Click Here for Graphic

   SPC AC 110531
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1131 PM CST WED MAR 10 2010
   
   VALID 111200Z - 121200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF FL...
   
   ...SYNOPSIS...
   
   BROAD UPPER LOW WILL PERSIST OVER THE CNTRL U.S. THURSDAY. SEVERAL
   VORTICITY MAXIMA WILL CONTINUE TO ROTATE THROUGH THIS FEATURE. THE
   VORT MAX OVER ERN KS/WRN MO AS OF WEDNESDAY EVENING IS FORECAST TO
   LIFT NWD INTO ERN NEB/IA...WHILE VORT MAX CURRENTLY OVER THE SWRN
   U.S. WILL CONTINUE ESEWD...REACHING THE LOWER MS VALLEY BY THE END
   OF THE PERIOD. INITIAL SURFACE LOW WILL OCCLUDE OVER THE UPPER MS
   VALLEY WITH TRAILING FRONT EXTENDING SWD THROUGH WRN PARTS OF THE TN
   AND LOWER MS VALLEY. SECONDARY LOW SHOULD DEVELOP OVER THE LOWER MS
   VALLEY THURSDAY NIGHT IN ASSOCIATION WITH APPROACHING IMPULSE. A
   QUASI-STATIONARY BOUNDARY WILL LIKELY PERSIST FROM SRN GA NWWD
   THROUGH CNTRL AL.
   
   ...SRN PARTS OF THE GULF COASTAL STATES AND FL...
   
   SWLY LOW-LEVEL JET LOCATED WITHIN THE DIVERGENT EXIT REGION OF A
   STRONG SUBTROPICAL UPPER JET IS FORECAST TO SHIFT EWD THROUGH THE
   NERN GULF AND THE FL PENINSULA THURSDAY. THIS FEATURE WILL HELP
   TRANSPORT RICHER BOUNDARY LAYER MOISTURE WITH UPPER 60S DEWPOINTS
   NEWD THROUGH THE PENINSULA. WEAK LAPSE RATES AND WIDESPREAD CLOUDS
   WILL LIMIT MLCAPE IN MOST AREAS TO BELOW 1000 J/KG. STORMS WILL BE
   ONGOING THURSDAY WITHIN THE BROAD ZONE OF ISENTROPIC LIFT AND
   THETA-E ADVECTION OVER THE SRN PORTIONS OF THE GULF COASTAL STATES.
   THESE STORMS WILL BE EMBEDDED WITHIN STRONG VERTICAL SHEAR WITH
   LARGE LOW HODOGRAPHS SUPPORTIVE OF SUPERCELLS. HOWEVER...THE
   ACTIVITY MAY BE SLIGHTLY ELEVATED...WHICH ALONG WITH A THE MARGINAL
   THERMODYNAMIC ENVIRONMENT WOULD SERVE AS A LIMITING FACTOR FOR
   SEVERE STORMS. A GREATER THREAT FOR SEVERE STORMS WILL MATERIALIZE
   AS ACTIVITY DEVELOPS EWD THROUGH THE FL PENINSULA WHERE INFLUX OF
   RICHER MOISTURE AND GRADUAL DESTABILIZATION OF THE BOUNDARY LAYER
   WILL OCCUR. LARGE HODOGRAPHS AND BULK SHEAR WILL SUPPORT A THREAT
   FOR EMBEDDED SUPERCELLS AND BOWING SEGMENTS WITH ISOLATED DAMAGING
   WIND AND TORNADOES POSSIBLE.
   
   SEVERE THREAT MAY UNDERGO A TEMPORARY DECREASE THURSDAY
   EVENING...BUT MAY INCREASE AGAIN LATER THURSDAY NIGHT AS THE
   LOW-LEVEL JET REDEVELOPS OVER THE PENINSULA DOWNSTREAM FROM
   ADVANCING SRN STREAM IMPULSE.
   
   
   ...MID MS AND OH VALLEY AREAS...
   
   DIABATIC WARMING WITHIN DRY SLOT AND BENEATH UPPER THERMAL TROUGH
   ACCOMPANYING NWD EJECTING VORT MAX WILL CONTRIBUTE TO A ZONE OF
   STEEP MID LEVEL LAPSE RATES ACROSS IL THROUGH WRN PARTS OF THE TN
   VALLEY. AN AXIS OF MODEST INSTABILITY WITH MLCAPE BELOW 800 J/KG
   WILL BE POSSIBLE IN THIS REGION. ADDITIONAL STORMS MAY DEVELOP ALONG
   AND EAST OF OCCLUDED FRONT AS THE ATMOSPHERE DESTABILIZES DURING THE
   AFTERNOON. VERTICAL SHEAR WILL REMAIN SUFFICIENT FOR UPDRAFT
   ROTATION WITH ISOLATED LARGE HAIL AND PERHAPS A COUPLE OF TORNADOES.
   THIS AREA WILL CONTINUE TO BE MONITORED FOR A POSSIBLE SLIGHT RISK
   IN LATER UPDATES.
   
   
   ...LOWER MS VALLEY AND WRN TN VALLEY AREA...
   
   
   TRAILING PORTIONS OF FRONT WILL LIKELY STALL OVER THE LOWER MS
   VALLEY. VORT MAX NOW OVER THE SWRN STATES WILL REACH THIS REGION
   THURSDAY NIGHT. ASCENT AND STEEPER LAPSE RATES ACCOMPANYING THE
   IMPULSE WILL OVERTAKE THIS BOUNDARY AND CONTRIBUTE TO
   DESTABILIZATION AND THUNDERSTORM INITIATION. GIVEN TIME OF DAY AND
   MODEST LOW-LEVEL MOISTURE...STORMS WILL LIKELY REMAIN ELEVATED...BUT
   STEEP LAPSE RATES AND A RELATIVELY DRY BOUNDARY LAYER WILL
   CONTRIBUTE TO A THREAT FOR ISOLATED HAIL AND STRONG WIND GUSTS.
   
   ..DIAL/HURLBUT.. 03/11/2010
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z