Fire Weather Outlook Discussion
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000
FNUS28 KWNS 012050
FWDD38

DAY 3-8 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0350 PM CDT WED JUL 01 2015

VALID 031200Z - 091200Z

THE BEGINNING OF THE EXTENDED PERIOD /D3-FRI/ WILL BE CHARACTERIZED
BY A BROAD MID/UPPER-LEVEL TROUGH STRETCHING FROM THE HIGH PLAINS
EWD TO THE ATLANTIC SEABOARD. FARTHER WEST...ANTICYCLONIC FLOW
CENTERED OVER THE GREAT BASIN SHOULD SLOWLY DE-AMPLIFY AND SHIFT
EWD...AS A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN W/NWLY FLOW ALOFT
TRANSLATE ACROSS THE PAC NW. MOREOVER...A WEAK PERTURBATION ALONG
THE WRN PERIPHERY OF THE ANTICYCLONE IS LIKELY TO PROGRESS NWD OVER
NRN CA INTO SRN ORE BY D5/SUN. A REX-BLOCK PATTERN IS EXPECTED TO
EVOLVE OFF THE WEST COAST BY THE END OF THE WEEKEND...BUT GLOBAL
GUIDANCE THEN DIVERGES BY EARLY NEXT WEEK REGARDING THE EVOLUTION OF
THE INTERACTION BETWEEN THE ASSOCIATED OFFSHORE LOW AND A STOUT
IMPULSE OVER THE PAC NW.

...D3/FRI-D4/SAT -- PACIFIC NW...
WITH THE PERSISTENCE OF ABOVE-NORMAL TEMPERATURES OVER THE PAC
NW...RH VALUES WILL CONTINUE TO BE LOW /DAILY MINS AROUND 10-20
PERCENT/ EAST OF THE CASCADE RANGE...SUPPORTED BY DRY W/NWLY FLOW.
AS AN IMPULSE PROGRESSES SEWD THROUGH BRITISH
COLUMBIA/ALBERTA...SOME MODEST ENHANCEMENT IN LOW-LEVEL FLOW WILL
FAVOR BREEZY CONDITIONS AND A CONCOMITANT INCREASE IN THE
FIRE-WEATHER THREAT EAST OF THE CASCADES D3/FRI-D4/SAT. AS
SUCH...THE PREVIOUS 40-PERCENT DELINEATION WAS MAINTAINED FOR D3/FRI
WITH ONLY MINOR ADJUSTMENTS...AND A NEW 40-PERCENT DELINEATION IS
INTRODUCED /GENERALLY CENTERED AROUND THE COLUMBIA BASIN/ FOR
D4/SAT.

...D3/FRI-D5/SUN -- PORTIONS OF THE CNTRL/NRN SIERRA...WRN GREAT
BASIN...AND SRN CASCADES...
AS THE AFOREMENTIONED WEAK PERTURBATION SLOWLY LIFTS NORTH THROUGH
NRN CA AND INTO SRN ORE LATE THIS WEEK INTO THE
WEEKEND...MID/UPPER-LEVEL MOISTURE AND INSTABILITY SHOULD ALSO
INCREASE OVER THE REGION. FORECAST PWAT VALUES AROUND 0.8-1.2 INCHES
WILL PROBABLY FAVOR MORE OF A WET-TSTM MODE DURING THIS PERIOD...AND
AS SUCH NO DELINEATION WILL BE INTRODUCED. HOWEVER...THE PRESENCE OF
DRY FUELS AND MODEST STORM MOTIONS SHOULD SUPPORT AT LEAST A FEW
LIGHTNING-RELATED IGNITIONS...PRIMARILY AROUND THE CNTRL/NRN SIERRA
AND WRN GREAT BASIN D3/FRI-D4/SAT...AND THEN PROGRESSING NWD INTO
THE SRN CASCADES BY D4/SAT-D5/SUN. FURTHERMORE...WITH THIS NON-ZERO
DRY-TSTM POTENTIAL...DELINEATIONS MAY BE REQUIRED IN LATER UPDATES.

..PICCA.. 07/01/2015

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




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