530  
FNUS22 KWNS 180638  
FWDDY2  
 
DAY 2 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0138 AM CDT THU OCT 18 2018  
 
VALID 191200Z - 201200Z  
   
..SYNOPSIS
 
 
A UPPER-LEVEL ANTI-CYCLONE IS FORECAST TO BE CENTERED OVER THE  
PACIFIC NORTHWEST ON DAY 2/FRIDAY, WHILE A WEAK UPPER LOW REMAINS  
JUST OFF THE COAST OF SOUTHERN CA. SURFACE HIGH PRESSURE OVER GREAT  
BASIN AND NORTHERN/CENTRAL ROCKIES WILL FOSTER OFFSHORE FLOW ACROSS  
SOUTHERN CA THROUGH THE PERIOD.  
   
..PORTIONS OF SOUTHERN CA
 
 
THE SURFACE PRESSURE GRADIENT FROM LAX-TPH AND LAX-DAG IS FORECAST  
TO STRENGTHEN CLOSE TO CRITICAL THRESHOLDS FRIDAY MORNING, AND  
MODERATE TO PERHAPS STRONG/GUSTY NORTHEASTERLY WINDS ARE EXPECTED.  
THE BEST POTENTIAL FOR LOCALLY CRITICAL-LEVEL WINDS APPEARS TO BE  
FOR THE HIGHER TERRAIN OF VENTURA AND LOS ANGELES COUNTIES, WHERE  
ISOLATED SUSTAINED WINDS OF 20-25 MPH COULD OCCUR, WITH SOME HIGHER  
GUSTS TO 35-40 MPH POSSIBLE. WIDESPREAD 15-20 MPH OFFSHORE FLOW  
APPEARS LIKELY ELSEWHERE IN MUCH OF THE LOWER TERRAIN/VALLEYS OF  
SOUTHERN CA. POOR OVERNIGHT RH RECOVERY IS EXPECTED FROM LATE  
THURSDAY EVENING INTO FRIDAY MORNING GIVEN THE GRADUALLY  
STRENGTHENING LOW-LEVEL FLOW AND LOCAL DOWNSLOPE WARMING/DRYING  
EFFECTS. AS DIURNAL HEATING AND MIXING OF THE BOUNDARY LAYER OCCURS  
FRIDAY MORNING AND AFTERNOON, RH VALUES WILL EASILY FALL INTO THE  
10-15% RANGE ACROSS MOST OF COASTAL SOUTHERN CA.  
 
SOME CONSIDERATION WAS GIVEN TO INTRODUCING A CRITICAL AREA FOR  
PARTS OF VENTURA AND LOS ANGELES COUNTIES, BUT THE LACK OF STRONGER  
MID TO UPPER-LEVEL WINDS AND THE MARGINAL FORECAST SURFACE PRESSURE  
GRADIENT BOTH SUGGEST A BROAD ELEVATED DELINEATION IS APPROPRIATE  
FOR NOW. A CRITICAL UPGRADE MAY BE NEEDED IN A LATER UPDATE IF THE  
FORECAST SURFACE PRESSURE GRADIENT STRENGTHENS ANY FURTHER.  
 
..GLEASON.. 10/18/2018  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
 
 

 
 
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