Wildfire in Oregon, July 25 to 31, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
929 AM PDT SAT JUL 25 2009

.SHORT TERM...UPDATE...THE UPPER LOW OVER EASTERN WASHINGTON HAS
RETROGRADED SLIGHTLY DURING THE LAST 12 HOURS...BUT IS STILL
EXPECTED TO SHIFT EAST THEN SOUTHEAST DURING THE NEXT 24 HOURS. AN
AREA OF SHOWERS WITH STRAY LIGHTNING STRIKES HAS BEEN ROTATING INTO
KITTITAS COUNTY AND HAVE UPDATED TO SCATTERED COVERAGE OF SHOWERS
AND EXPANDED SLIGHTLY ISOLATED THUNDERSTORM COVERAGE ACROSS KITTITAS
COUNTY FOR THE REST OF THIS MORNING. FOR THIS AFTERNOON...HAVE
SHIFTED ISOLATED THUNDERSTORM THREAT A BIT FURTHER SOUTH TO INCLUDE
THE COLUMBIA RIVER GORGE. MEANWHILE...EXPECT BEST PUNCH OF MOISTURE
THIS AFTERNOON TO BE OVER YAKIMA AND KITTITAS COUNTY. THUS HAVE
DECREASED THUNDERSTORM COVERAGE TO ISOLATED OVER KLICKITAT COUNTY
FOR THIS AFTERNOON. ELSEWHERE HAVE DECREASED THUNDERSTORM COVERAGE
OVER PORTIONS OF NORTHEAST OREGON AS EXPECT SOME DRIER AIR TO MOVE
INTO THE NORTHERN BLUES. THE OTHER MAIN UPDATE THIS MORNING WAS TO
LOWER AFTERNOON HIGH TEMPS OVER KITTITAS AND YAKIMA COUNTIES DUE TO
THE INCREASED CLOUD COVER...SHOWERS AND STORMS. 90

.LONG TERM...PREVIOUS DISCUSSION...A HIGHLY AMPLITUDE RIDGE OVER THE
EASTERN PACIFIC AND THE WEST COAST WILL KEEP CONDITIONS DRY THROUGH
MOST OF NEXT WEEK. AN INVERTED SURFACE THERMAL TROUGH WILL LINGER
EAST OF THE CASCADES THAT WILL BRING HOT DAYTIME TEMPERATURES...
MAINLY IN THE 90S WITH A FEW AREAS IN THE COLUMBIA BASIN AND THE
JOHN DAY BASIN SOARING TO 100-105. 00Z GFS AND ECMWF ARE IN BETTER
AGREEMENT SHOWING AN UPPER LOW MOVING TOWARDS THE OREGON COAST ON
FRIDAY. HOWEVER...THEY DIFFER WITH THE TRACK OF THE SYSTEM BY
SATURDAY (ECMWF KEEPS THE LOW OFFSHORE WHILE GFS SWINGS IT
EASTWARD). IF 06Z AND 12Z RUN CONTINUE TO ADVERTISE THIS PATTERN...
THUNDERSTORMS WILL LIKELY BE INCLUDED IN THE FORECAST TO PORTIONS OF
EASTERN OREGON FOR FRIDAY.

&&

.AVIATION...18Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH 18Z
SUNDAY. UPPER LOW OVER WASHINGTON WILL WRAP MOISTURE INTO NORTHERN
PORTIONS OF THE FORECAST AREA TODAY INTO SUNDAY MORNING CREATING
SOME CLOUD COVER AND A CHANCE OF SHOWERS AND THUNDERSTORMS VCNTY
KYKM THIS AFTERNOON AND EVENING. LIGHT TERRAIN DRIVEN WINDS THIS
MORNING WILL BECOME NWLY 10-15KT THIS AFTERNOON AND EVENING BEFORE
BECOMING TERRAIN DRIVEN ONCE AGAIN OVERNIGHT. 78

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  94  64  96  67 /  10  10  20  20
ALW  94  67  94  67 /  10  10  20  20
PSC  96  66  98  70 /  10  10  20  10
YKM  88  67  96  70 /  30  30  20  10
HRI  95  64  97  68 /  10  10  20  10
ELN  86  65  97  66 /  30  20  20  10
RDM  93  51  94  52 /   0   0  10  10
LGD  90  55  90  57 /  10  20  20  20
GCD  93  57  93  58 /  10  10  10  10
DLS  95  63  97  65 /  20  10  20  10

&&

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

THREAT INDEX
TODAY : GREEN
SUNDAY : GREEN
MONDAY : GREEN

GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON

90/78/78

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
916 AM PDT SAT JUL 25 2009

ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-261415-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
CENTRAL OREGON-LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-
WALLOWA COUNTY-FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-
NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES-JOHN DAY BASIN-
OCHOCO-JOHN DAY HIGHLANDS-
EASTERN COLUMBIA RIVER GORGE OF WASHINGTON-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
916 AM PDT SAT JUL 25 2009

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS
     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, EAST SLOPES
     OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF WASHINGTON, KITTITAS VALLEY, YAKIMA VALLEY, LOWER
     COLUMBIA BASIN OF WASHINGTON, NORTHWEST BLUE MOUNTAINS, EASTERN
     COLUMBIA RIVER GORGE OF OREGON, GRANDE RONDE VALLEY, WALLOWA
     COUNTY, NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE
     MOUNTAINS OF OREGON, OCHOCO-JOHN DAY HIGHLANDS

AN UPPER LEVEL LOW OVER EASTERN WASHINGTON WILL REMAIN STATIONARY
THROUGH TONIGHT. MOISTURE WRAPPING AROUND THIS SYSTEM WILL COMBINE
WITH INSTABILITY TO TRIGGER ISOLATED TO SCATTERED THUNDERSTORMS OVER
PORTIONS OF THE REGION.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THUNDERSTORMS SUNDAY
     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, EAST SLOPES
     OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF WASHINGTON, 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, LOWER COLUMBIA
     BASIN OF OREGON, GRANDE RONDE VALLEY, WALLOWA COUNTY,
     FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON, NORTHERN BLUE
     MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF OREGON,
     NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES, JOHN DAY
     BASIN, OCHOCO-JOHN DAY HIGHLANDS

THUNDERSTORMS MONDAY
     NORTHWEST BLUE MOUNTAINS, WALLOWA COUNTY, NORTHERN BLUE
     MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF OREGON,
     OCHOCO-JOHN DAY HIGHLANDS

EXCESSIVE HEAT MONDAY
     LOWER COLUMBIA BASIN OF WASHINGTON, LOWER COLUMBIA BASIN OF
     OREGON

EXCESSIVE HEAT TUESDAY AND WEDNESDAY
     EASTERN COLUMBIA RIVER GORGE OF WASHINGTON, KITTITAS VALLEY,
     YAKIMA VALLEY, LOWER COLUMBIA BASIN OF WASHINGTON, FOOTHILLS
     OF THE BLUE MOUNTAINS OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF OREGON, NORTH CENTRAL OREGON, LOWER COLUMBIA BASIN OF
     OREGON, FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON

EXCESSIVE HEAT THURSDAY AND FRIDAY
     EASTERN COLUMBIA RIVER GORGE OF WASHINGTON, YAKIMA VALLEY,
     LOWER COLUMBIA BASIN OF WASHINGTON, FOOTHILLS OF THE BLUE
     MOUNTAINS OF WASHINGTON, EASTERN COLUMBIA RIVER GORGE OF
     OREGON, NORTH CENTRAL OREGON, LOWER COLUMBIA BASIN OF OREGON,
     FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON

THE UPPER LOW WILL CONTINUE TO AFFECT THE REGION SUNDAY...THEN EXIT
THE REGION SUNDAY NIGHT. THUS ISOLATED TO SCATTERED THUNDERSTORMS
WILL CONTINUE OVER PORTIONS OF THE AREA SUNDAY AND SUNDAY NIGHT.
LINGERING MOISTURE MONDAY MAY RESULT IN FEW SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS. OTHERWISE...THE UPPER LEVEL HIGH
PRESSURE RIDGE LOOKS TO REBUILD OVER THE PACIFIC NORTHWEST ON
MONDAY. THIS WOULD RESULT IN A RETURN TO HOT AND DRY CONDITIONS
LASTING THROUGH THE END OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

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

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

WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML

ALL LETTERS IN THE ABOVE URL ARE LOWER CASE...EXCEPT THE H IN
CURRENTHAZARDS.