Categorical Graphic
Probabilistic Tornado 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
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
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 201931
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0131 PM CST TUE NOV 20 2012
   
   VALID 202000Z - 211200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...PACIFIC NW...
   
   A MARGINAL THREAT OF ISOLATED STRONG WIND GUSTS WILL EXIST UNTIL
   AROUND 21Z ALONG A PORTION OF THE WASHINGTON COASTAL COUNTIES WITH
   FORCED CONVECTIVE BAND THAT HAS MOVED ONSHORE. INTENSITIES APPEAR TO
   HAVE PEAKED...AND ACTIVITY IS EXPECTED TO BEGIN A WEAKENING TREND AS
   IT CONTINUES FARTHER INLAND. REF SWOMCD 2121 FOR MORE DETAILS.
   OTHERWISE ONLY MINOR ADJUSTMENTS HAVE BEEN MADE TO CURRENT FORECAST.
   
   ..DIAL.. 11/20/2012
   
   .PREV DISCUSSION... /ISSUED 1023 AM CST TUE NOV 20 2012/
   
   ...WA/ORE/ID/WRN MT REST OF TODAY THROUGH TONIGHT...
   A FAST/MOIST WSWLY/WLY MID-LEVEL FLOW REGIME WILL EXTEND FROM THE
   PACIFIC NW TO THE NRN ROCKIES DOWNSTREAM FROM A CLOSED CYCLONIC
   CIRCULATION CENTERED OFF THE BRITISH COLUMBIA/NW CONUS COAST. WHILE
   THE CENTER OF THE CYCLONE WILL MOVE LITTLE DURING THE REMAINDER OF
   THE PERIOD...A SERIES OF IMPULSES PIVOTING AROUND THE CYCLONE WILL
   MAINTAIN WIDESPREAD PRECIPITATION WITH EMBEDDED ISOLATED DEEPER
   CONVECTION. ONE IMPULSE WITH ASSOCIATED LIGHTNING IS CURRENTLY
   APPROACHING THE WA COAST...WITH THE 12Z QUILLAYUTE RAOB INDICATING
   JUST OVER 200 J/KG OF CAPE FOR A PARCEL LIFTED FROM AROUND 1.5 KFT
   AGL. ADDITIONAL UPSTREAM IMPULSES WILL MOVE ASHORE THROUGH THE
   REMAINDER OF THE PERIOD AND SUPPORT ISOLATED THUNDERSTORMS AMIDST
   7-8-C/KM MID-LEVEL LAPSE RATES FROM AROUND PUGET SOUND WWD TO THE
   NWRN WA COAST AND THEN SWD TO THE WRN ORE COAST.
   
   FARTHER EAST ACROSS THE INTERMOUNTAIN WEST TO THE NRN ROCKIES --
   I.E. EAST OF THE GENERAL-THUNDERSTORM AREA -- FORECAST SOUNDINGS
   INDICATE THE PRESENCE OF ONLY MARGINAL AMOUNTS OF ELEVATED BUOYANCY
   THROUGH TONIGHT...AND AN ISOLATED THUNDERSTORM OR TWO CANNOT BE
   RULED OUT. HOWEVER...RELATIVELY WARMER 500-MB TEMPERATURES AND ONLY
   WEAK DEEP ASCENT SHOULD KEEP THUNDERSTORM COVERAGE SUFFICIENTLY
   LIMITED SUCH THAT A GENERAL-THUNDERSTORM AREA IS NOT WARRANTED.
   
   ...FAR SERN AZ/SRN NM/TRANS-PECOS REGION OF SWRN TX TONIGHT...
   A MID-LEVEL CYCLONE OFF THE CNTRL BAJA CA COAST WILL TRACK ENEWD AND
   REACH NEAR THE NRN SIERRA MADRE OCCIDENTALS BY LATE TONIGHT. THE
   INFLUX OF RELATIVELY RICHER 750-700-MB MOISTURE BENEATH STEEP
   MID-LEVEL LAPSE RATES WILL PROMOTE MARGINAL DESTABILIZATION FOR
   ELEVATED PARCELS. WEAK LOW/MID-LEVEL ISENTROPIC ASCENT LEADING THE
   CYCLONE MAY SUPPORT ISOLATED THUNDERSTORMS...ESPECIALLY LATE IN THE
   NIGHT AND IN CLOSEST PROXIMITY TO THE INTERNATIONAL BORDER...AS
   AFFIRMED BY OUTPUT FROM THE EXPERIMENTAL SPC SSEO
   CONVECTION-ALLOWING MODEL GUIDANCE.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z