Wildfire in Oregon, September 14 to 24, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1030 PM PDT TUE SEP 13 2005

UPDATED AVIATION SECTION

.UPDATE...A FAST MOVING SYSTEM IN CANADA IS BRINGING A FEW CLOUDS
TO SOUTHEAST WASHINGTON WHILE SKIES ARE MOSTLY CLEAR IN EASTERN
OREGON. WINDS ARE DECREASING OVER THE AREA. RADIATIONAL COOLING
FROM THESE CONDITIONS WILL ALLOW TEMPERATURES TO DROP OVERNIGHT.
CURRENT FORECAST REFLECTS THESE TRENDS AND NO UPDATE IS EXPECTED.
COONFIELD

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. THE
CURRENT TAF AND TWEBS REFLECT THE FORECAST FOR TONIGHT AND TOMORROW.

&&

.PREV DISCUSSION... (ISSUED 220 PM PDT TUE SEP 13 2005)

SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT.  THE PACIFIC NORTHWEST
WILL REMAIN BETWEEN WEATHER SYSTEMS THROUGH EARLY THURSDAY.  DRY
NORTHWESTERLY FLOW BETWEEN LOW PRESSURE SYSTEMS...ONE IN THE GULF OF
ALASKA...AND ANOTHER MOVING EAST OF THE ROCKIES...WILL KEEP THE AREA
UNDER FAIR SKIES AND SEASONABLE TEMPERATURES.  A WEAK DISTURBANCE
AHEAD OF THE PACIFIC TROUGH WILL SWING NORTH OF THE AREA WEDNESDAY
AND WEDNESDAY NIGHT SPREADING SOME HIGH CLOUDS OVERHEAD...BUT NO
PRECIPITATION IS EXPECTED.  BY THURSDAY THE UPPER-LEVEL FLOW WILL
BEGIN TO SHIFT MORE OUT OF THE WEST AND SOUTHWEST.  THIS WILL
INITIATE INCREASING WINDS IN THE COLUMBIA RIVER GORGE AND KITTITAS
VALLEY...AS WELL AS ALLOW SOME PACIFIC MOISTURE TO TRICKLE OVERHEAD
INCREASING CLOUDS DURING THAT PERIOD. CANTIN

LONG TERM...FRIDAY THROUGH TUESDAY. A LOW PRESSURE SYSTEM IS
FORECAST TO MOVE INTO THE PACNW FRIDAY. CONFIDENCE IS INCREASING
THAT THIS SYSTEM WILL NOT BE AS COLD OR HAVE AS MUCH ENERGY AS THE
SYSTEM LAST WEEKEND.  HOWEVER...IT SHOULD BRING AMPLE MOISTURE WITH
IT ACROSS THE EASTERN PACIFIC OCEAN FOR A CLOUDY WEEKEND AND SOME
LOW CHANCES FOR PRECIPITATION.  BY FRIDAY THE ASSOCIATED COLD FRONT
WILL HAVE MOVED SOUTHEAST OF THE PENDLETON FORECAST AREA...BUT
ENOUGH INSTABILITY IS EXPECTED TO REMAIN FOR A SLIGHT CHANCE OF
THUNDERSTORMS FRIDAY FOR MOST LOCATIONS EXCEPT THE LOWER COLUMBIA
BASIN.  FRIDAY AND FRIDAY NIGHT IS THE BEST PERIOD FOR SHOWER
CHANCES AS WELL.  A DRYING WARMING PERIOD IS EXPECTED AFTER THE
SYSTEM EXITS TO THE EAST...FOLLOWED BY A WEAK QUICK-MOVING
DISTURBANCE MONDAY. THIS DISTURBANCE SHOULD ONLY BRING SOME MID AND
HIGH LEVEL CLOUDS ALONG WITH POSSIBLY BREEZY CONDITIONS.  BY TUESDAY
MORNING A WEAK RIDGE OF HIGH PRESSURE IS EXPECTED.  AS SUCH A MOSTLY
CLEAR NIGHT COULD LEAD TO BELOW FREEZING TEMPERATURES IN THE
DESCHUTES PLATEAU AND IN THE COLDER MOUNTAIN VALLEYS TUESDAY
MORNING.  80

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&

TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
76/76/76

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1130 AM PDT TUE SEP 13 2005

WAZ024>030-ORZ041>050-141200-
EAST SLOPES OF THE SOUTHERN CASCADES-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS-EASTERN COLUMBIA RIVER GORGE OF OREGON-
NORTH CENTRAL OREGON-CENTRAL OREGON-
LOWER COLUMBIA BASIN OF OREGON-
FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON-BLUE MOUNTAINS-
JOHN DAY BASIN-OCHOCO-JOHN DAY HIGHLANDS-GRANDE RONDE VALLEY-
WALLOWA COUNTY-
1130 AM PDT TUE SEP 13 2005

UPDATED DAY ONE PERIOD.

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

DRY NORTHWEST FLOW WILL REMAIN OVER THE REGION WITH GENERALLY FAIR
SKIES AND DRY CONDITIONS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

A BENIGN...DRY WESTERLY FLOW ALOFT ON WEDNESDAY WILL BACK TO THE
SOUTHWEST ON THURSDAY AHEAD OF AN UPPER LEVEL SHORT WAVE MOVING OUT
OF THE GULF OF ALASKA. THE SHORT WAVE WILL DEVELOP AND DEEPEN INTO
AN UPPER LEVEL TROUGH AS IT MOVES INTO THE PACIFIC NORTHWEST ON
FRIDAY. THE TROUGH WILL INCREASE CLOUD COVER AND INTRODUCE A CHANCE
OF SHOWERS...MAINLY OVER THE MOUNTAINS ON FRIDAY..FRIDAY NIGHT AND
SATURDAY. MARGINAL INSTABILITY ASSOCIATED WITH THE TROUGH WILL
INTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS ON FRIDAY. THE TROUGH
WILL EXIT THE REGION ON SATURDAY NIGHT WITH LINGERING ISOLATED
SHOWERS OVER THE MOUNTAINS OF NORTHEAST OREGON AND SOUTHEAST
WASHINGTON. THEN HIGH PRESSURE WILL BUILD OVER THE REGION FOR DRY
AND STABLE CONDITIONS ON SUNDAY AND MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

PROTOTYPE GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:

WEATHER.GOV/PENDLETON

AND SELECT GRAPHICAL HAZARDS.

POLAN