Fire Weather Outlook Discussion
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FNUS22 KWNS 201649
FWDDY2

DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1149 AM CDT MON APR 20 2015

VALID 211200Z - 221200Z

...PORTIONS OF THE MID/UPPER MO VALLEY...
MODIFIED THE ELEVATED AREA OF THE REGION TO BETTER REFLECT THE MOST
RECENT GUIDANCE BUT THE OVERALL FORECAST REMAINS ON TRACK. COOL
TEMPERATURES /LOW TO MID 50S/ CONTINUE TO BE THE FACTOR MOST
PROHIBITIVE TO A GREATER FIRE WEATHER THREAT.

...PORTIONS OF SERN AZ AND SWRN NM...
ELEVATED TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS ARE STILL
EXPECTED ACROSS THE REGION AS TEMPERATURES CLIMB INTO THE 70S AND
80S...RH VALUES DROP BELOW 10 PERCENT...AND SWLY WINDS APPROACH
15-20 MPH.

..MOSIER.. 04/20/2015

.PREV DISCUSSION... /ISSUED 0347 AM CDT MON APR 20 2015/

...SYNOPSIS...
DEEP...EXPANSIVE MID/UPPER LOW WILL REMAIN CENTERED OVER SRN/ERN
ONTARIO...WITH SEVERAL PERTURBATIONS ROTATING AROUND ITS PERIPHERY
ALONG THE PLAINS...SOUTHEAST...AND EAST COAST. FARTHER WEST...A WEAK
CLOSED LOW WILL PROGRESS ONSHORE SRN CA...WITH A RESULTANT PATTERN
OF SOMEWHAT ENHANCED DIFLUENT FLOW OVER AZ/NM.

THE SFC RESPONSE TO THESE FEATURES WILL BE CHARACTERIZED BY RIDGING
EXTENDING FROM THE NRN PLAINS TO THE SERN STATES...WITH A LARGE
OCCLUDED LOW TO THE NORTHEAST OVER ONTARIO. MEANWHILE...A BROAD AREA
OF LOW PRESSURE WILL BE SITUATED OVER THE INTER-MOUNTAIN WEST.

...PORTIONS OF THE MID/UPPER MO VALLEY...
CONTINUING FROM THE PREVIOUS DAY...A DEEP CHANNEL OF ENHANCED NWLY
FLOW WILL BE SITUATED OVER THE NRN PLAINS AND PORTIONS OF THE
MIDWEST. IN COMBINATION WITH DIURNAL HEATING AND A WELL-MIXED
BL...THIS CORRIDOR OF STRONG FLOW WILL YIELD W/NWLY SUSTAINED SFC
WINDS AROUND 20-30 MPH. FURTHERMORE...THE PREVIOUSLY DISCUSSED
SYNOPTIC PATTERN WILL CONTINUE TO FUNNEL DRY AIR OVER THE
REGION...WITH FCST PWAT VALUES AROUND 0.2-0.4 IN. THEREFORE...RH
VALUES WILL LIKELY FALL BELOW 25 PERCENT /WITH SOME READINGS BELOW
20 PERCENT/ ACROSS MUCH OF THE MO VALLEY AND SURROUNDING AREA.
CONSIDERING THAT FINE FUELS WILL BE PRE-CONDITIONED VIA THE
DRY/WINDY DAY PRIOR TO THE PERIOD...AN ELEVATED DELINEATION HAS BEEN
INTRODUCED FOR PORTIONS OF CNTRL/SERN SD...FAR NERN NE...AND NWRN
IA.

...PORTIONS OF SERN AZ AND SWRN NM...
A DRY AIR MASS /CHARACTERIZED BY PWAT VALUES AOB 0.4 IN/ WILL BE
POSITIONED OVER THE SWRN CONUS ON D2/TUE. DIURNAL HEATING WILL
RESULT IN RH VALUES LIKELY FALLING BELOW 15 PERCENT ACROSS MUCH OF
THE DESERT SOUTHWEST. AS SOME MODEST ENHANCEMENT OF MID-LEVEL FLOW
OCCURS...RESULTING FROM THE APPROACHING LOW PRESSURE ALOFT...ROBUST
BL MIXING WILL FAVOR SWLY SFC WINDS INCREASING TO AROUND 15-20 MPH.
IN COMBINATION WITH DRY FUELS...THESE CONDITIONS ARE CONSISTENT WITH
AN ELEVATED FIRE-WX THREAT /WITH LOCALLY CRITICAL CONDITIONS/ AND A
DELINEATION HAS BEEN INTRODUCED. FURTHERMORE...A CRITICAL AREA
AROUND FAR SERN AZ/SWRN NM MAY BECOME NECESSARY IF CONFIDENCE IN
STRONGER FLOW INCREASES.

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




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