SPC Day 2 Fire Weather Outlook

DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0324 AM CDT TUE OCT 16 2012

VALID 171200Z - 181200Z

...SYNOPSIS...
A DEEP TROUGH WILL AMPLIFY OVER THE PLAINS AND MS VALLEY...WHILE AN
EMBEDDED LOW CENTER TRACKS SEWD FROM THE SRN CANADIAN PRAIRIES TO
THE UPPER MS VALLEY. AN EXTENSIVE/INTENSE TROPOSPHERIC WIND SPEED
MAXIMUM WILL STRETCH FROM THE NRN ROCKIES SEWD INTO THE BASE OF THE
TROUGH ACROSS THE CNTRL/SRN PLAINS AND MIDDLE/LOWER MS VALLEY. AT
THE SFC...A COLD FRONT WILL MOVE EWD/SWD ACROSS PARTS OF THE
CNTRL/ERN CONUS AND EXTEND FROM THE GREAT LAKES REGION TO THE
LOWER/MIDDLE TX COAST BY LATE WEDNESDAY NIGHT. HIGH PRESSURE WILL
BUILD INTO THE NRN/CNTRL GREAT BASIN AND NRN/CNTRL ROCKIES DURING
THE PERIOD.

...NRN/CNTRL PLAINS...WRN PARTS OF THE MIDDLE/UPPER MS VALLEY...
IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...A BROAD AREA OF
STRONG TO VERY STRONG WLY/NWLY SFC WINDS IS EXPECTED TO IMPACT THE
AREA IN ASSOCIATION WITH THE TROPOSPHERIC WIND SPEED MAXIMUM AND A
TIGHT SFC PRESSURE GRADIENT. SUSTAINED WIND SPEEDS OF 20-35 MPH WITH
HIGHER GUSTS WILL BE LIKELY.

THE INFLUX OF A RELATIVELY DRIER...CONTINENTAL AIR MASS WILL AID IN
MODEST BOUNDARY-LAYER DRYING DURING THE AFTERNOON AS TEMPERATURES
INCREASE. THESE FACTORS MAY ACT TO ENHANCE THE FIRE WEATHER THREAT
WHERE FUELS ARE DRY.

THE AREA OF GREATEST CONCERN FOR ELEVATED FIRE WEATHER CONDITIONS
WILL BE ACROSS CNTRL/WRN NEB...NWRN KS...AND NERN/E-CNTRL CO. IN
THIS AREA...PRECIPITATION HAS BEEN BELOW NORMAL DURING THE PAST
COUPLE OF WEEKS ACROSS MANY LOCATIONS...AND DROUGHT CONDITIONS ARE
PRESENT. HOWEVER...AREAS OF FRONT-RELATED PRECIPITATION -- ALBEIT
LIGHT -- PRIOR TO BOUNDARY-LAYER DRYING COULD MITIGATE THE FIRE
WEATHER THREAT TO SOME EXTENT. ALSO...POST-FRONTAL COLD ADVECTION
WILL CURTAIL THE DEGREE OF SFC WARMING AND THUS THE FIRE WEATHER
THREAT SOMEWHAT. FURTHERMORE...IN THE ABSENCE OF A WARMER AIR
MASS...RH VALUES MAY BE MARGINAL...WITH CONFIDENCE IN CRITICALLY LOW
RH VALUES OCCURRING ON ANY MORE THAN A BRIEF/SPOTTY BASIS NOT
SUFFICIENTLY HIGH FOR CRITICAL DESIGNATION AT THIS TIME.

ELSEWHERE ACROSS THE NRN/CNTRL PLAINS...AND ACROSS WRN PARTS OF THE
MIDDLE/UPPER MS VALLEY...AREAS OF ENHANCED FIRE WEATHER THREAT MAY
EXIST. HOWEVER...EITHER /1/ EVEN COOLER TEMPERATURES/HIGHER SFC RH
AND/OR /2/ THE OCCURRENCE OF EVEN GREATER PRECIPITATION AMOUNTS
DURING THE PAST COUPLE OF WEEKS...SHOULD MITIGATE THE FIRE WEATHER
THREAT FURTHER COMPARED TO CNTRL/WRN NEB...NWRN KS...AND
NERN/E-CNTRL CO.

...NWRN/N-CNTRL/CNTRL NM...
OVER THE SWRN FLANK OF THE AFOREMENTIONED TROPOSPHERIC WIND SPEED
MAXIMUM...A ZONE OF MODESTLY ENHANCED 700-MB FLOW WILL SUPPORT NWLY
SFC WINDS OF 15 TO AROUND 20 MPH WITH HIGHER GUSTS. AND...WITH A DRY
AIR MASS CHARACTERIZED BY 0.1-0.2-INCH PW VALUES...A MODEST
DEEPENING OF THE MIXED LAYER WILL SUPPORT RH VALUES FROM 10 TO 15
PERCENT. AS SUCH...ELEVATED FIRE WEATHER CONDITIONS ARE
EXPECTED...GIVEN BELOW-NORMAL PRECIPITATION DURING THE PAST SEVERAL
WEEKS IN MANY LOCATIONS. HOWEVER...IN THE ABSENCE OF STRONGER
LOW/MID-LEVEL FLOW...CONFIDENCE IN CRITICALLY STRONG SUSTAINED WIND
SPEEDS OCCURRING ON ANY MORE THAN A BRIEF/SPOTTY BASIS IS TOO LOW
FOR CRITICAL DESIGNATION.

...COASTAL RANGES AND ADJACENT FOOTHILLS OF SRN CA...
AN ENHANCED PRESSURE GRADIENT TO THE SW OF HIGH PRESSURE BUILDING
INTO THE NRN/CNTRL GREAT BASIN AND THE NRN/CNTRL ROCKIES WILL
SUPPORT ELY/ENELY SFC WINDS GENERALLY FROM 10 TO 15 MPH WITH HIGHER
GUSTS...STRONGEST THROUGH FAVORED PASSES AND CANYONS. AREAS OF
DOWNSLOPE EFFECTS WILL ALLOW FOR WARMING/DRYING OF THE BOUNDARY
LAYER...WITH RH VALUES EXPECTED TO FALL TO 10-20 PERCENT. AS
SUCH...ELEVATED FIRE WEATHER CONDITIONS MAY OCCUR.

THERE IS VARIABILITY AMONGST MODEL SOLUTIONS REGARDING THE STRENGTH
OF THE SFC PRESSURE GRADIENT AND MAGNITUDE OF THE CORRESPONDING
WINDS. HOWEVER...THE SOLUTIONS DEPICTING THE TIGHTEST
GRADIENT/STRONGEST WINDS INDICATE NO MORE THAN A
BRIEF/SPOTTY/MARGINAL THREAT FOR CRITICALLY STRONG WINDS.
THUS...WITH THE LACK OF CONFIDENCE /OWING TO MODEL VARIABILITY/ IN
EVEN BRIEF/SPOTTY/MARGINAL CRITICALLY STRONG WINDS DEVELOPING...FIRE
WEATHER HIGHLIGHTS HAVE NOT BEEN INCLUDED AT THIS TIME.

..COHEN.. 10/16/2012

...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
via SPC Forecast Products http://www.spc.noaa.gov/products/fire_wx/fwdy2.html