Dec 31, 2010 1730 UTC Day 2 Convective Outlook
Updated: Fri Dec 31 17:29:58 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20101231 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20101231 1730 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 311728
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1128 AM CST FRI DEC 31 2010
   
   VALID 011200Z - 021200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   A DEEP CLOSED LOW CENTERED OVER THE UPPER MIDWEST AT THE START OF
   DAY 2 /NEW YEARS DAY/ IS EXPECTED TO UNDERGO FURTHER DEEPENING AS
   THIS SYSTEM BECOMES NEGATIVELY-TILTED AND EXTENDS FROM NRN ONTARIO
   TO SRN QUEBEC BY 12Z SUNDAY.  THE MEAN LONGWAVE TROUGH OVER THE
   CENTRAL CONUS WILL SHIFT SLOWLY EWD AS AN UPSTREAM SHORTWAVE TROUGH
   TRACKS SEWD FROM THE NRN ROCKIES TO THE CENTRAL PLAINS ON DAY
   2...AND ADDITIONAL IMPULSES DIG SSEWD THROUGH CENTRAL CANADA TOWARD
   THE N CENTRAL STATES.  A COLD FRONT ATTENDANT TO THE PRIMARY UPPER
   SYSTEM IS EXPECTED TO EXTEND FROM THE CENTRAL GREAT LAKES SSWWD
   THROUGH THE OH/TN VALLEYS TO THE LOWER MS VALLEY AT 12Z SATURDAY. 
   THIS BOUNDARY WILL MOVE EWD AND OFF THE NRN ATLANTIC COAST BY 12Z
   SUNDAY...WHILE THE SRN EXTENT STRETCHES SWWD THROUGH THE SERN STATES
   TO CENTRAL GULF.
   
   ...CENTRAL GULF STATES...
   AT 12Z SATURDAY...SHOWERS/EMBEDDED TSTMS ARE EXPECTED TO BE ONGOING
   ALONG THE COLD FRONT FROM THE UPPER OH/TN VALLEYS TO THE LOWER MS
   VALLEY AND INTO THE GULF OF MEXICO.  ADDITIONAL CONVECTION SHOULD
   ALSO BE ONGOING INVOF A PRE-FRONTAL LOW LEVEL CONFLUENCE ZONE
   EXTENDING FROM THE NORTH CENTRAL GULF INTO SWRN AL.
   
   STRONGEST FORCING FOR ASCENT IS EXPECTED TO REMAIN WELL NORTH OF
   THIS REGION AS A COUPLE OF SHORTWAVE TROUGHS TRACK NEWD FROM THE
   UPPER MS VALLEY AND CENTRAL PLAINS INTO ERN CANADA.  NEUTRAL-VERY
   WEAK HEIGHT FALLS ARE FORECAST ACROSS THE CENTRAL GULF COAST STATES
   ON NEW YEARS DAY WITH MID-UPPER LEVEL WINDS INCREASING OVER THIS
   REGION AS THE SRN EXTENT OF THE POLAR JET TRANSLATES NEWD FROM THE
   LOWER MS VALLEY TO THE MID ATLANTIC STATES.  MODELS INDICATED A SWLY
   LLJ WILL LIKELY STRENGTHEN /50-60 KT/ FRIDAY NIGHT/EARLY SATURDAY
   MORNING ALONG AND W OF THE SRN/CENTRAL APPALACHIANS FROM AL TO
   OH...WITH THE SRN EXTENT OF THIS LLJ HAVING SPEEDS UP TO 40 KT ALONG
   THE N CENTRAL GULF COAST.  HOWEVER...THE GULF COAST PORTION OF THE
   LLJ IS EXPECTED TO VEER AND WEAKEN GREATLY BY SATURDAY AFTERNOON AS
   THIS JET MOVES NEWD ACROSS THE CENTRAL APPALACHIANS.
   
   SLY LOW LEVEL WINDS WILL MAINTAIN A MOIST BOUNDARY LAYER DURING THE
   FIRST HALF OF THE PERIOD ACROSS THE WARM SECTOR.  HOWEVER...LIMITED
   SURFACE HEATING DUE TO EXISTING PRECIPITATION/CONVECTIVE CLOUDINESS
   ALONG AND AHEAD OF THE COLD FRONT AND WEAK LAPSE RATES SHOULD
   GREATLY MINIMIZE INLAND INSTABILITY VALUES.  THIS OUTLOOK WILL
   MAINTAIN LOW SEVERE WEATHER PROBABILITIES FOR STORMS DURING THE
   FIRST HALF OF THE PERIOD THAT MAY BE ABLE TO ATTAIN LOW LEVEL STORM
   ROTATION/ISOLATED TORNADO THREAT AND/OR DAMAGING WINDS.  HOWEVER...
   EVENTUAL WEAKENING OF LOW LEVEL WINDS BY SATURDAY AFTERNOON AND WEAK
   EFFECTIVE BULK SHEAR WILL FURTHER REDUCE THE SEVERE WEATHER THREAT.
   
   ..PETERS.. 12/31/2010
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z