160  
FNUS22 KWNS 071920  
FWDDY2  
 
DAY 2 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0119 PM CST THU DEC 07 2017  
 
VALID 081200Z - 091200Z  
   
..CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA
 
   
..CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN COLORADO
 
 
PORTIONS OF EASTERN COLORADO HAVE BEEN UPGRADED TO CRITICAL FOR THIS  
OUTLOOK UPDATE. GREATER CONFIDENCE IN CRITICAL RH (13-15%) WILL  
PERSIST DURING PEAK HEATING HOURS AS TEMPERATURES RISE INTO THE 50S  
F AND DEWPOINTS FALL TO BETWEEN 0-5F. NORTH OF THE CRITICAL AREA AN  
ELEVATED FIRE WEATHER DELINEATION REMAINS, ALTHOUGH COOLER  
TEMPERATURES MAY LIMIT THE SPATIAL EXTENT OF CRITICAL RH IN MOST  
AREAS. THIS REGION WILL BE REEVALUATED FOR A POTENTIAL UPGRADE TO  
CRITICAL IN LATER FORECAST UPDATES.  
 
ELSEWHERE, OFFSHORE FLOW - ENHANCED IN TERRAIN-FAVORED AREAS - WILL  
CONTINUE TO FOSTER WIDESPREAD ELEVATED TO CRITICAL FIRE WEATHER  
CONDITIONS THROUGHOUT THE FORECAST PERIOD IN SOUTHERN CALIFORNIA.  
20-30 MPH SURFACE WINDS (WITH HIGHER GUSTS), AREAS OF DRY FUELS, AND  
CRITICAL (6-15%) RH VALUES WILL ALL SUPPORT RAPID FIRE SPREAD AND  
POTENTIALLY DANGEROUS/UNPREDICTABLE FIRE BEHAVIOR.  
 
SEE THE PREVIOUS DISCUSSION BELOW FOR MORE INFORMATION.  
 
..COOK.. 12/07/2017  
   
PREV DISCUSSION
 
/ISSUED 0144 AM CST THU DEC 07 2017/  
   
..SYNOPSIS
 
 
POSITIVELY TILTED UPPER TROUGHING EXTENDING FROM THE OH VALLEY TO  
THE SOUTHERN PLAINS WILL DEVELOP EASTWARD ACROSS THE SOUTHEAST ON  
DAY 2/FRIDAY AS LARGE-SCALE UPPER TROUGHING REMAINS PROMINENT ACROSS  
MUCH OF THE CENTRAL/EASTERN CONUS. AN UPPER RIDGE WILL BE PRESENT  
OVER THE WESTERN CONUS. AT THE SURFACE, HIGH PRESSURE WILL REMAIN  
CENTERED OVER THE NORTHERN ROCKIES AND GREAT BASIN, ALTHOUGH IT IS  
FORECAST TO BE WEAKER THAN DAY 1/THURSDAY. A SURFACE TROUGH SHOULD  
MOVE SOUTHEASTWARD ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS.  
   
..PORTIONS OF SOUTHERN CA
 
 
DUE TO THE WEAKER SURFACE HIGH DESCRIBED ABOVE, THE FORECAST SURFACE  
PRESSURE GRADIENT ACROSS SOUTHERN CA SHOULD BE LESS STRONG THROUGH  
MUCH OF DAY 2/FRIDAY. STILL, STRONG/GUSTY OFFSHORE WINDS ARE  
EXPECTED TO SUPPORT A CONTINUED CRITICAL FIRE WEATHER RISK THROUGH  
MUCH OF THE DAY 2/FRIDAY PERIOD, ESPECIALLY IN HIGHER TERRAIN WHERE  
WINDS SHOULD BE GREATER. SUSTAINED NORTHEASTERLY TO EASTERLY SURFACE  
WINDS OF 20-30 MPH WILL LIKELY OCCUR IN CONJUNCTION WITH CRITICALLY  
LOWERED RH VALUES OF 5-15% THROUGH AT LEAST FRIDAY EVENING ACROSS  
MUCH OF SOUTHERN CA. HIGHER GUSTS OF 40-50 MPH WILL BE POSSIBLE IN  
THE MOUNTAINS/FOOTHILLS. WITH NO RECENT PRECIPITATION, FUELS WILL  
REMAIN VERY DRY AND RECEPTIVE TO LARGE FIRE STARTS AND SPREAD.  
   
..PORTIONS OF THE CENTRAL/SOUTHERN HIGH PLAINS
 
 
BEHIND THE SURFACE TROUGH MENTIONED PREVIOUSLY, SUSTAINED  
NORTH-NORTHWESTERLY WINDS OF 20-30 MPH WILL OCCUR ACROSS PARTS OF  
EASTERN CO/WESTERN KS SOUTHWARD INTO THE TX/OK PANHANDLES, EASTERN  
NM, AND FAR WESTERN OK. ALTHOUGH TEMPERATURES ARE FORECAST TO REMAIN  
SOMEWHAT COOL, GENERALLY IN THE LOW TO MID 50S, A VERY DRY  
ANTECEDENT AIRMASS COUPLED WITH LOW-LEVEL MIXING WILL ENCOURAGE RH  
VALUES TO FALL INTO THE 15-25% RANGE FOR A FEW HOURS FRIDAY  
AFTERNOON. COUPLED WITH DRY/DORMANT FUELS, THESE FORECAST  
METEOROLOGICAL CONDITIONS SUPPORT AN ELEVATED DELINEATION ACROSS  
PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS. THE LACK OF AN EVEN  
WARMER/DRIER LOW-LEVEL AIRMASS PRECLUDES A CRITICAL AREA AT THIS  
TIME.  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
 
 

 
 
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