Storm Prediction Center Day 1 Fire Weather Outlook

Created: Sat Sep 24 16:31:03 UTC 2016 (20160924 1700Z Day 1 FireWX shapefile | 20160924 1700Z Day 1 FireWX KML)

Day 1 Fire Weather Forecast graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
Critical 13,741 10,108,625 Los Angeles, CA...Riverside, CA...Glendale, CA...San Bernardino, CA...Ontario, CA...

Click for Day 1 FireWX Areal Outline Product

   ZCZC SPCFWDDY1 ALL
   FNUS21 KWNS 241626

   DAY 1 FIRE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1126 AM CDT SAT SEP 24 2016

   VALID 241700Z - 251200Z

   ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA...

   ...MOUNTAINS AND ADJACENT FOOTHILLS OF SOUTHERN CA...
   RECENT SURFACE ANALYSIS REVEALED OFFSHORE GRADIENTS OF 7.5 MB FROM
   LAX-TPH AND 3 MB LAX-DAG. GUSTS OVER 20 MPH ARE STILL OCCURRING AT
   SOME OF THE HIGHER ELEVATIONS SITES WITH LOCALIZED GUSTY CONDITIONS
   EXPECTED TO PERSIST THROUGH THE LATE AFTERNOON. WINDS WILL PICK UP
   AGAIN TONIGHT WITH SUSTAINED SPEEDS ABOVE 25 MPH AND GUSTS OVER 45
   MPH POSSIBLE. GIVEN THE ANTICIPATED POOR RH RECOVERY AND PERSISTENT
   WARM TEMPERATURES TONIGHT...WIDESPREAD CRITICAL FIRE WEATHER
   CONDITIONS ARE STILL LIKELY ACROSS MUCH OF THE REGION. NO CHANGES
   ARE NEEDED TO THE ONGOING FORECAST.

   ...NORTHERN CA -- INCLUDING WRN SLOPES OF THE SIERRA...SACRAMENTO
   VALLEY AND NRN COASTAL RANGES...
   LOCALLY CRITICAL CONDITIONS ARE POSSIBLE ACROSS PORTIONS OF THE
   SACRAMENTO VALLEY THIS AFTERNOON WHERE TEMPERATURES WILL BE IN THE
   90S AND MIN RH VALUES IN THE TEENS. NLY WINDS WILL LIKELY STAY BELOW
   20 MPH ACROSS MUCH OF THE REGION BUT LOCALIZED AREAS MAY EXPERIENCE
   WINDS GREATER THAN 20 MPH FOR AN HOUR OR TWO. GIVEN THESE EXPECTED
   CONDITIONS...ADDED THE SACRAMENTO VALLEY TO THE ELEVATED DELINEATION
   ACROSS THE REGION. HIGHER ELEVATION AREAS ARE MORE LIKELY TO
   EXPERIENCE STRONGER WINDS AND LOWER RH VALUES TONIGHT AS POOR RH
   RECOVERY OCCURS AMIDST A MODEST OFFSHORE GRADIENT AND NO CHANGE TO
   THE PREVIOUS FORECAST WAS NEEDED IN THESE AREAS.

   ..MOSIER.. 09/24/2016

   .PREV DISCUSSION... /ISSUED 0236 AM CDT SAT SEP 24 2016/

   ...SYNOPSIS...
   A FAIRLY AMPLIFIED MID/UPPER-LEVEL TROUGH WILL EXTEND FROM NORTHERN
   MEXICO NORTH/NORTHEASTWARD TO THE CANADIAN PRAIRIES...AS ONE
   EMBEDDED LOW LIFTS NORTHEAST ACROSS THE DAKOTAS...AND ANOTHER
   DEVELOPS OVER THE DESERT SOUTHWEST LATE IN THE PERIOD.
   MEANWHILE...UPSTREAM RIDGING WILL BUILD OVER CALIFORNIA AND PARTS OF
   THE PACIFIC NORTHWEST...RESULTING IN A TIGHTENING HEIGHT GRADIENT
   AND INCREASING NORTHERLY FLOW ALOFT FROM THE NORTHERN ROCKIES TO THE
   DESERT SOUTHWEST. 

   ...PORTIONS OF SOUTHERN CALIFORNIA...
   WITH AN INVERTED SFC TROUGH SITUATED ALONG/NEAR THE CA COAST...A
   BUILDING RIDGE ACROSS THE GREAT BASIN WILL TIGHTEN THE PRESSURE
   GRADIENT...FAVORING INCREASING OFFSHORE FLOW. ELEVATED/LOCALLY
   CRITICAL CONCERNS SHOULD BE ONGOING ACROSS HIGHER
   ELEVATIONS/TERRAIN-FAVORED LOCATIONS THIS MORNING...WITH NORTHEAST
   WINDS AROUND 15-25 MPH SUSTAINED AND POOR RH RECOVERIES /GENERALLY
   AROUND 20-30 PERCENT/. WIND SPEEDS MAY EXPERIENCE SOME DIURNAL
   WEAKENING...BUT TERRAIN-FAVORED LOCATIONS MAY MAINTAIN SUSTAINED
   WINDS OVER 20 MPH...AS MID-LEVEL FLOW VEERS FROM THE NORTH TO
   NORTHEAST -- INCREASING THE OFFSHORE COMPONENT. MEANWHILE...RH
   VALUES WILL FALL TO AROUND 8-20 PERCENT. AS SUCH...POCKETS OF
   CRITICAL CONCERNS MAY CONTINUE THROUGH THE DAY.

   THE GREATEST POTENTIAL FOR RAPID FIRE SPREAD ARRIVES LATE TONIGHT AS
   THE OFFSHORE PRESSURE GRADIENT NOCTURNALLY STRENGTHENS...SUPPORTING
   SUSTAINED NORTHEAST WINDS AROUND 20-30 MPH /WITH GUSTS UP TO 45-55
   MPH/. RH RECOVERIES WILL BE POOR ONCE AGAIN...SUCH THAT MORE
   WIDESPREAD CRITICAL CONCERNS ARE ANTICIPATED TONIGHT.

   ...PORTIONS OF NORTHERN CALIFORNIA...
   ELEVATED/LOCALLY CRITICAL CONDITIONS ARE ANTICIPATED LATE TONIGHT
   ACROSS THE WESTERN SLOPES OF THE SIERRA NEVADA...AS WELL AS NEAR
   COASTAL RANGES OF NORTHERN CALIFORNIA. INCREASING OFFSHORE FLOW
   /WITH SUSTAINED WINDS AROUND 15-25 MPH/...POOR RH RECOVERIES...AND
   DRY FUELS WILL ENHANCE THE THREAT FOR RAPID FIRE SPREAD...WITH THE
   GREATEST POTENTIAL VERY LATE IN THE PERIOD WHEN EASTERLY DOWNSLOPE
   FLOW MAXIMIZES.

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

      

Fire Weather/Forecast Products/Home