Fire Weather Outlook Discussion
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FNUS21 KWNS 031544
FWDDY1

DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1043 AM CDT FRI JUL 03 2015

VALID 031700Z - 041200Z

NO CHANGES NEEDED TO ONGOING FORECAST.  CURRENT OBSERVATIONS SUGGEST
THAT LOCALIZED AREAS IN THE LEE OF THE CASCADES WILL SEE BRIEF
PERIODS OF GUSTY WINDS EXCEEDING CRITICAL CRITERIA...BUT THESE
CONDITIONS ARE NOT EXPECTED TO OCCUR ON A WIDESPREAD BASIS.  FOR
ADDITIONAL INFORMATION...PLEASE SEE DISCUSSION BELOW.

..COOK.. 07/03/2015

.PREV DISCUSSION... /ISSUED 0355 AM CDT FRI JUL 03 2015/

...SYNOPSIS...
THE PERSISTENT WESTERN UNITED STATES MID-/UPPER-LEVEL RIDGE WILL
DAMPEN SLIGHTLY DURING THE FORECAST PERIOD AS A STRONG TROUGH MOVES
SOUTHEAST INTO ALBERTA. DOWNSTREAM...A BROAD TROUGH WILL PERSIST
ACROSS THE EASTERN UNITED STATES. AT THE SURFACE...A TROUGH WILL
DEVELOP EAST OF THE CASCADES COINCIDENT WITH PERSISTENT HOT/DRY
CONDITIONS. ACROSS THE EAST...A REMNANT SURFACE FRONT WILL BRING
SHOWERS AND THUNDERSTORMS TO LARGE PORTIONS OF THE SOUTH/EAST UNITED
STATES.

...CENTRAL OREGON NORTHWARD INTO CENTRAL WASHINGTON...
THE APPROACH OF THE AFOREMENTIONED CANADIAN TROUGH WILL ACT TO
ENHANCE MID-LEVEL FLOW ACROSS THE PACIFIC NORTHWEST. THE FOLLOWING
DOWNSLOPE WILL SUPPORT THE DEVELOPMENT OF A LEE TROUGH AND AN
INCREASE IN SURFACE-PRESSURE GRADIENT. THIS STRONGER SURFACE
GRADIENT WILL RESULT IN STRONGER WINDS THAN PREVIOUS DAYS.
ADDITIONALLY GUSTIER CONDITIONS WILL BE POSSIBLE OWING TO MID-LEVEL
WINDS MIXING DOWN TO THE SURFACE IN THE PRESENCE OF A DEEP BOUNDARY
LAYER. AFTERNOON RELATIVE-HUMIDITY VALUES MAY FALL AS LOW AS THE
TEENS ACROSS CENTRAL OREGON AND WASHINGTON...WHICH WHEN COUPLED WITH
THE STRONGER WIND POTENTIAL WILL LEAD TO ELEVATED-TO-LOCALLY
CRITICAL FIRE-WEATHER CONDITIONS.

...FAR SOUTHERN OREGON...NORTHERN CALIFORNIA...SIERRA
MOUNTAINS...AND MUCH OF NEVADA...
AN INCREASE IN MID-LEVEL MOISTURE AND ASCENT ASSOCIATED WITH COMPACT
VORTICITY MAXIMA LIFTING NORTHWARD ON THE WESTERN PERIPHERY OF THE
WESTERN UNITED STATES RIDGE WILL RESULT IN AFTERNOON THUNDERSTORMS.
GIVEN PRECIPITABLE-WATER VALUES NEAR OR ABOVE AN INCH AND WEAK
MID-LEVEL FLOW DUE TO CLOSER PROXIMITY TO THE MID-LEVEL RIDGE
/ESPECIALLY ACROSS NEVADA/....ANY THUNDERSTORM THAT DOES DEVELOP
SHOULD BE CAPABLE OF PRODUCING WETTING RAINS. HOWEVER...DESPITE THE
POTENTIAL FOR WETTING RAINS IN THUNDERSTORM CORES LIGHTNING STRIKES
OUTSIDE OF THUNDERSTORM CORES WILL STILL POSE A POTENTIAL TO IGNITE
NEW FIRE STARTS.

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




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