Fire Weather Outlook Discussion
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FNUS21 KWNS 011654
FWDDY1

DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1153 AM CDT FRI AUG 01 2014

VALID 011700Z - 021200Z

...CRITICAL FIRE WEATHER AREA FOR NERN ORE...ERN SLOPES OF WA
CASCADES...

THE ONGOING FORECAST FOR DRY THUNDERSTORMS ACROSS PORTIONS OF THE
NORTHWEST GENERALLY REMAINS ON TRACK /SEE PREVIOUS DISCUSSION BELOW/
WITH A COUPLE OF CHANGES IN THIS UPDATE. FIRST...THE MOUNTAINS OF
NERN WA HAVE BEEN REMOVED FROM THE SCATTERED DRY THUNDERSTORM
AREA...AS THE LATEST MODEL GUIDANCE /12Z CONVECTION-ALLOWING RUNS
AND 09Z SREF/ SUGGESTS LESS THAN SCATTERED COVERAGE OF
THUNDERSTORMS.  NEVERTHELESS...ISOLATED TO WIDELY SCATTERED DRY
THUNDERSTORMS WILL BE POSSIBLE ACROSS THE REGION...ESPECIALLY AFTER
00Z.  SECOND...THE ISOLATED DRY THUNDERSTORM AREA WAS EXPANDED
ACROSS CENTRAL ID WHERE SCATTERED THUNDERSTORM COVERAGE APPEARS
PROBABLE DURING THE AFTERNOON.  ALTHOUGH SURFACE RH VALUES WILL BE
MARGINAL AND STORM MOTIONS WILL BE RELATIVELY SLOW...LOW PW VALUES
/AOB 0.75 INCH/ WILL SUPPORT A MIX OF WET AND DRY STORMS AND
ISOLATED DRY THUNDERSTORM POTENTIAL.

..JIRAK.. 08/01/2014

.PREV DISCUSSION... /ISSUED 0400 AM CDT FRI AUG 01 2014/

...SYNOPSIS...
THE UPPER-AIR PATTERN TODAY WILL FEATURE A RIDGE OVER MUCH OF THE
WRN U.S. AND A LONGWAVE TROUGH OVER THE ERN HALF OF THE CONUS.
EARLY MORNING SATELLITE IMAGERY SHOWS A DISTURBANCE NEAR THE OREGON
COAST AND THIS FEATURE WILL MOVE NNEWD AND FAVOR THE BREAKING DOWN
OF THE UPPER RIDGE OVER THE PACIFIC NW STATES TODAY AND TONIGHT.
ISOLATED TO SCATTERED THUNDERSTORMS ARE FORECAST IN ASSOCIATION WITH
THE UPPER DISTURBANCE AND WILL RESULT IN AN ELEVATED TO CRITICAL
FIRE WEATHER THREAT FOR DRY THUNDERSTORMS OVER PORTIONS OF
WASHINGTON AND OREGON.

...ERN HALF OF ORE AND WA / NRN ID / NWRN NV / EXTREME NERN CA...
AN APPRECIABLE THUNDERSTORM AND ASSOCIATED LIGHTNING EPISODE WILL
BEGIN EARLY TODAY AND GRADUALLY INCREASE DURING THE DAY WHILE MOVING
NEWD INTO NERN ORE AND THE ERN HALF OF WA AND LINGERING TONIGHT.
THE UPPER DISTURBANCE IS FORECAST TO INVOKE MID-LEVEL HEIGHT FALLS
OVER ORE AND WA TODAY AS LARGE-SCALE ASCENT SPREADS DOWNSTREAM IN
CONCERT WITH THE DISTURBANCE FAVORING THE DEVELOPMENT OF
THUNDERSTORMS.  THE 00Z/01 OTX RAOB SHOWED A PRE-CONDITIONED STEEP
LAPSE RATE AND VERY DRY BOUNDARY-LAYER PROFILE IN ADVANCE OF THE
APPROACHING UPPER FEATURE.  FORECAST SOUNDINGS SHOW DEEP/WELL-MIXED
BOUNDARY LAYERS WITH RH IN THE TEENS FROM NWRN NV NWD TO THE WA/BC
BORDER.  ALTHOUGH PW VALUES WILL RANGE FROM 0.7-1.0 INCH AND
GENERALLY 15 MPH STORM MOTIONS WILL SUPPORT A MIX MODE OF WET AND
DRY STORMS...WIDELY SCATTERED TO SCATTERED THUNDERSTORM COVERAGE IS
FORECAST AND SUPPORTED BY THE LATEST DETERMINISTIC AND
CONVECTION-ALLOWING MODEL OUTPUT.  FOR THESE REASONS...SATISFACTORY
CONFIDENCE IS ATTAINED FOR A CRITICAL SCATTERED DRY THUNDERSTORM
THREAT.

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



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