Storm Prediction Center Day 1 Fire Weather Outlook

Created: Sat Jul 4 09:02:02 UTC 2015 (20150704 1200Z Day 1 FireWX shapefile | 20150704 1200Z Day 1 FireWX KML)

Day 1 Fire Weather Forecast graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast

Click for Day 1 FireWX Areal Outline Product

   ZCZC SPCFWDDY1 ALL
   FNUS21 KWNS 040857

   DAY 1 FIRE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0357 AM CDT SAT JUL 04 2015

   VALID 041200Z - 051200Z

   ...SYNOPSIS...
   DEVELOPMENT OF MID-/UPPER-LEVEL HIGH-OVER-LOW BLOCK ACROSS THE
   EASTERN PACIFIC OCEAN WILL CONTINUE THROUGH THE FORECAST
   PERIOD...WITH A TROUGH-OVER-RIDGE PATTERN EVOLVING DOWNSTREAM ACROSS
   WESTERN NORTH AMERICA. THIS MID-/UPPER-LEVEL CONFIGURATION WILL
   FAVOR HOT/DRY CONDITIONS ACROSS THE WESTERN UNITED STATES /WITH
   UNSEASONABLY WARM TEMPERATURES ACROSS THE PACIFIC NORTHWEST/ AND AN
   INCREASE IN MID-LEVEL MOISTURE /DRAWN NORTHWARD FROM THE TROPICAL
   EASTERN PACIFIC/. FARTHER EAST...MEAN TROUGHING WILL PERSIST ACROSS
   EASTERN NORTH AMERICA.

   AT THE SURFACE...A REMNANT FRONT ACROSS THE SOUTHERN/EASTERN UNITED
   STATES WILL ONCE AGAIN SUPPORT SHOWER/THUNDERSTORM DEVELOPMENT.

   ...CENTRAL OREGON NORTHWARD INTO CENTRAL AND EASTERN WASHINGTON...
   A SHORT-WAVE TROUGH MOVING THROUGH THE LARGER WESTERN CANADA TROUGH
   WILL ACT TO STRENGTHEN THE WESTERLY COMPONENT OF THE MID-LEVEL FLOW
   ACROSS THIS REGION. THE RESULTANT DOWNSLOPE FLOW WILL SUPPORT AN
   INCREASING SURFACE-PRESSURE GRADIENT AS A LEE TROUGH DEVELOPS EAST
   OF THE CASCADES. THIS WILL ALLOW FOR SURFACE WINDS TO INCREASE TO
   BETWEEN 10-20 MPH WITH STRONGER GUSTS POSSIBLE.
   ADDITIONALLY...HOT/DRY ANTECEDENT CONDITIONS...COUPLED WITH
   DOWNSLOPE FLOW...WILL ALLOW FOR SURFACE AND NEAR-SURFACE 
   RELATIVE-HUMIDITY VALUES TO FALL QUICKLY INTO THE TEENS AND LOWER
   20S PERCENT RANGE DURING THE AFTERNOON. THE COMBINATION OF STRONGER
   WINDS AND LOWER RELATIVE-HUMIDITY VALUES WILL YIELD
   ELEVATED-T0-LOCALLY CRITICAL FIRE-WEATHER CONDITIONS.

   ...GREAT BASIN...SIERRA MOUNTAINS...NORTHERN CALIFORNIA...AND FAR
   SOUTHERN OREGON...
   MID-/UPPER-LEVEL MOISTURE WILL CONTINUE TO INCREASE ACROSS THE AREA
   AS MOISTURE IS DRAWN NORTHWARD ON THE WESTERN PERIPHERY OF THE
   SUB-TROPICAL RIDGE CENTERED OVER THE ROCKY MOUNTAINS. COINCIDENT
   WITH THIS INCREASE IN MOISTURE...CONVECTIVELY-INDUCED VORTICITY
   MAXIMA FROM PREVIOUS DAYS CONVECTION ARE EMBEDDED WITHIN THE
   MID-LEVEL FLOW AROUND THE SUB-TROPICAL RIDGE. ASCENT ASSOCIATED WITH
   THESE SUBTLE VORTICITY MAXIMA...ALONG WITH OROGRAPHIC EFFECTS...WILL
   YIELD ISOLATED-TO-SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS.
   FORECAST SOUNDINGS SUGGEST PRECIPITABLE-WATER VALUES WILL BE HIGH
   ENOUGH TO SUPPORT WETTING RAINS WITHIN THUNDERSTORM CORES.
   HOWEVER...PERSISTENT DROUGHT ACROSS THE AREA HAS LEFT FUELS VERY DRY
   AND RECEPTIVE TO LIGHTNING INDUCED FIRES...ESPECIALLY FROM LIGHTNING
   STRIKES REMOVED FROM THUNDERSTORM CORES. ADDITIONALLY...VERY DRY
   SUB-CLOUD LAYERS WILL SUPPORT A DOWNBURST POTENTIAL WITH STRONGER
   THUNDERSTORMS. THIS WILL LEAD TO STRONG/GUSTY THUNDERSTORM OUTFLOW
   WINDS. PLEASE SEE THE LATEST SPC DAY-1 CONVECTIVE OUTLOOK FOR
   ADDITIONAL INFORMATION REGARDING THUNDERSTORM WIND POTENTIAL.

   ..MARSH.. 07/04/2015

   ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...

      

Fire Weather/Forecast Products/Home