SPC Day 1 Fire Weather Outlook

DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0357 AM CDT WED OCT 17 2012

VALID 171200Z - 181200Z

...CRITICAL FIRE WEATHER AREA FOR NERN AND PORTIONS OF E-CNTRL
CO...CNTRL AND PORTIONS OF WRN KS...CNTRL AND PORTIONS OF WRN
NEB...PARTS OF NWRN/N-CNTRL OK...

...SYNOPSIS...
A STRONG/DEEP TROUGH WILL AMPLIFY OVER THE PLAINS AND MS
VALLEY...WHILE AN EMBEDDED LOW CENTER TRACKS SEWD FROM THE SRN
CANADIAN PRAIRIES ACROSS PARTS OF THE NRN PLAINS TO THE UPPER MS
VALLEY. AN EXTENSIVE AND 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 TONIGHT. HIGH PRESSURE WILL BUILD INTO THE NRN/CNTRL
GREAT BASIN AND NRN/CNTRL ROCKIES DURING THE PERIOD.

...NERN AND PORTIONS OF E-CNTRL CO...CNTRL AND PORTIONS OF WRN
KS...CNTRL AND PORTIONS OF WRN NEB...PARTS OF NWRN/N-CNTRL OK...
IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...NWLY SFC WINDS OF
25-35 MPH WITH HIGHER GUSTS ARE EXPECTED IN ASSOCIATION WITH THE
TROPOSPHERIC WIND SPEED MAXIMUM AND A TIGHT SFC PRESSURE GRADIENT.
DEEP VERTICAL MIXING INTO THE STRONGER FLOW ALOFT WILL SUPPORT GUSTS
REACHING 45 MPH. THE INFLUX OF A RELATIVELY DRIER...CONTINENTAL AIR
MASS WILL AID IN BOUNDARY-LAYER DRYING DURING THE AFTERNOON AS
TEMPERATURES INCREASE INTO THE 50S AND 60S. MINIMUM RH VALUES ARE
EXPECTED TO RANGE FROM AROUND 14 TO 20 PERCENT...WITH THE LOWEST OF
THESE READINGS FROM NERN CO SEWD INTO NWRN OK. GIVEN THESE
FACTORS...AND ONGOING DROUGHT CONDITIONS WITH ADDITIONAL DRYING OF
FUELS OWING TO THE STRONG/VERY STRONG WINDS...CRITICAL DESIGNATION
IS WARRANTED.

...TO THE N/E OF THE CRITICAL AREA ACROSS ND...SD...ERN NEB...ERN
KS...WRN PORTIONS OF THE MID AND UPPER MS VALLEY...
AREAS OF ENHANCED FIRE WEATHER THREAT MAY EXIST AS WLY TO NWLY WINDS
OF 20-35 MPH AND HIGHER GUSTS AFFECT THE REGION. HOWEVER...COMPARED
TO CONDITIONS ACROSS THE CRITICAL AREA...TEMPERATURES ARE EXPECTED
TO BE RELATIVELY COOLER...WITH MINIMUM RH READINGS GENERALLY FROM 20
TO 40 PERCENT -- WITH EVEN HIGHER READINGS ACROSS PARTS OF NRN/ERN
ND AND NWRN/W-CNTRL MN. WITHOUT CRITICALLY LOW RH VALUES EXPECTED TO
OCCUR ON ANY MORE THAN A BRIEF/SPOTTY BASIS...THE CRITICAL AREA DOES
NOT EXTEND FARTHER N/E AT THIS TIME.

...TO THE S/SW OF THE CRITICAL AREA ACROSS PARTS OF
OK...NWRN/N-CNTRL TX...SERN CO...PARTS OF SWRN KS...
WINDS WILL ABRUPTLY BECOME NWLY TO NLY FOLLOWING FRONTAL PASSAGE AND
BECOME STRONG IN MANY LOCATIONS. RH VALUES WILL FALL THROUGH THE
AFTERNOON AS DRY POST-FRONTAL AIR INFILTRATES THE REGION. RH VALUES
COULD BRIEFLY REACH CRITICAL THRESHOLDS IN SOME LOCATIONS BEFORE
NOCTURNAL COOLING SUPPORTS INCREASING RH...THOUGH CONFIDENCE IN ANY
MORE THAN BRIEF INSTANCES OF CRITICALLY LOW RH VALUES OCCURRING IS
LOW. ALSO...WHILE STRONG SFC WINDS WILL BE MOST LIKELY ACROSS PARTS
OF CNTRL/S-CNTRL/WRN OK AND N-CNTRL TX...THE CONFIDENCE IN
SUBSTANTIAL COVERAGE/DURATION OF CRITICALLY STRONG SFC WINDS IS
LIMITED FARTHER W/NW FROM NWRN TX INTO THE OK PANHANDLE...AS WELL AS
ACROSS PARTS OF SWRN KS AND SERN CO -- I.E. OVER THE FRINGES OF THE
TROPOSPHERIC WIND SPEED MAXIMUM. AS SUCH...THE CRITICAL AREA DOES
NOT EXTEND FARTHER S/SW AT THIS TIME.

...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...
THE LATEST MULTI-DETERMINISTIC/ENSEMBLE MODEL CONSENSUS SUGGESTS
THAT THE 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
LOCALLY/BRIEFLY 20 MPH WITH HIGHER GUSTS. THE STRONGEST OF THESE
WINDS WILL BE FOUND 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 ARE ANTICIPATED. HOWEVER IN
THE ABSENCE OF A TIGHTER SFC PRESSURE GRADIENT...CRITICALLY STRONG
SUSTAINED WIND SPEEDS ARE NOT EXPECTED TO OCCUR ON ANY MORE THAN A
BRIEF/SPOTTY BASIS. THUS...CRITICAL DESIGNATION IS NOT WARRANTED.

...SACRAMENTO VALLEY...
THE MODESTLY ENHANCED SFC PRESSURE GRADIENT BETWEEN A CNTRL CA
COASTAL-AREA TROUGH AND HIGH PRESSURE BUILDING INTO THE NRN/CNTRL
GREAT BASIN AND THE NRN/CNTRL ROCKIES WILL SUPPORT NLY WINDS FROM 10
TO LOCALLY/BRIEFLY 20 MPH WITH HIGHER GUSTS. THE PRESENCE OF A DRY
AIR MASS...AIDED BY DOWNSLOPE EFFECTS IN SOME LOCATIONS...WILL
SUPPORT MINIMUM RH VALUES FROM 8 TO 14 PERCENT. THESE FACTORS WILL
YIELD AN ELEVATED FIRE WEATHER THREAT. HOWEVER...IN THE ABSENCE OF A
TIGHTER SFC PRESSURE GRADIENT...CRITICALLY STRONG SUSTAINED WIND
SPEEDS ARE NOT EXPECTED TO OCCUR ON ANY MORE THAN A BRIEF/SPOTTY
BASIS. AS SUCH...CRITICAL DESIGNATION IS NOT WARRANTED.

..COHEN.. 10/17/2012

...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
via SPC Forecast Products http://www.spc.noaa.gov/products/fire_wx/fwdy1.html