Nov 21, 2009 1730 UTC Day 2 Convective Outlook
Updated: Sat Nov 21 17:17:42 UTC 2009
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20091121 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20091121 1730 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 211716
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1116 AM CST SAT NOV 21 2009
   
   VALID 221200Z - 231200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   MODELS ARE IN AGREEMENT THROUGH THE DAY 2 PERIOD SHOWING A SHORT
   WAVE TROUGH...CURRENTLY MOVING EWD THROUGH SRN TX/NWRN GULF OF
   MEXICO PER WATER VAPOR IMAGERY...WILL DEAMPLIFY SUNDAY AS THIS
   FEATURE TRACKS THROUGH THE TN/OH VALLEYS.  AN OCCLUDED SURFACE LOW
   AND TRIPLE POINT LOCATED ALONG THE MS DELTA AND CENTRAL GULF
   COAST... RESPECTIVELY...AT 12Z SUNDAY WILL WEAKEN THIS PERIOD.  AS
   THIS PROCESS OCCURS...A NEW SURFACE LOW IS EXPECTED TO DEVELOP OFF
   THE SRN ATLANTIC COAST /E OF GA/.  MEANWHILE...GRADUAL HEIGHT RISES
   OVER THE SERN STATES WITH THE NEWD TRACK OF THE UPPER TROUGH SUGGEST
   A SURFACE FRONT RESIDING FROM NWRN FL TO SERN GA SHOULD REMAIN
   QUASI-STATIONARY THROUGH 12Z MONDAY.
   
   ...NRN FL PENINSULA/SERN GA...
   CURRENT THINKING REMAINS SIMILAR TO THE INITIAL DAY 2 OUTLOOK FOR AN
   ISOLATED THREAT FOR SEVERE STORMS...WITH THE PRIMARY THREAT BEING
   FOR A NON-ZERO POTENTIAL FOR AN ISOLATED/BRIEF TORNADO.  DEEP LAYER
   AND LOW LEVEL SHEAR VALUES WILL BE FAVORABLE FOR ORGANIZED STORMS/
   ROTATING UPDRAFTS THROUGH EARLY-MID SUNDAY AFTERNOON BEFORE THESE
   FAVORABLE KINEMATICS SHIFT NWD AWAY FROM THE WARM SECTOR. 
   HOWEVER...BOUNDARY LAYER DESTABILIZATION REMAINS THE PRIMARY
   LIMITING FACTOR GIVEN WEAK LAPSE RATES AND CLOUDINESS/PRECIPITATION
   ACROSS THE AREA OF CONCERN PRECLUDING GREATER INSTABILITY
   DEVELOPING.  WIDESPREAD SEVERE STORMS ARE NOT EXPECTED...BUT ANY
   AREAS THAT HAVE SOME SURFACE HEATING/DESTABILIZATION MAY PROVE
   SUFFICIENT FOR DEEP MOIST CONVECTION WITH A LOW SEVERE PROBABILITY
   GIVEN THE FAVORABLE KINEMATICS.  THE 5 PERCENT SEVERE PROBABILITY
   HAS BEEN SHIFTED A LITTLE WWD OVER THE FL PANHANDLE.  THIS IS
   PRIMARILY ALONG THE COASTAL AREAS TO ACCOUNT FOR THE TRIPLE POINT
   LOW REACHING THIS REGION SUNDAY AFTERNOON...AND SUBSEQUENTLY
   ENHANCING LOW LEVEL SHEAR VALUES FOR AN ISOLATED/BRIEF TORNADO
   AND/OR WATERSPOUT MOVING ONSHORE.
   
   ..PETERS.. 11/21/2009
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z