Wildfire in Oregon, August 2 to 10, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
250 PM PDT TUE AUG 2 2011

.SHORT TERM...TONIGHT THROUGH FRIDAY...MODELS CONTINUE TO SHOW A
RIDGE OF HIGH PRESSURE OVER MUCH OF THE COUNTRY FOR THE NEXT FEW
DAYS WITH A TROUGH OFF OF THE PACIFIC NORTHWEST COAST. THIS WILL
CONTINUE THE RECENT PATTERN OF SEASONABLY WARM AND DRY WEATHER OVER
MUCH OF THE AREA WITH ISOLATED TO SCATTERED THUNDERSTORMS IN THE
AFTERNOON AND EVENING FROM CENTRAL OREGON THROUGH THE MOUNTAINS OF
EASTERN OREGON. TEMPERATURES WILL CONTINUE TO REACH THE MID 80S TO
LOWER 90S EACH DAY WITH MID 70S TO MID 80S IN THE MOUNTAINS. THE
MAIN FORECAST CHALLENGE HAS BEEN TO JUDGE THE EFFECTS OF PASSING
DISTURBANCES AND MOVEMENT OF THE TROUGH ON THUNDERSTORM CHANCES EACH
DAY. THIS EVENING WE HAVE A DISTURBANCE MOVING THROUGH THE AREA AND
EXPECT ISOLATED THUNDERSTORMS TO BEGIN DEVELOPING IN THE NEXT FEW
HOURS OVER CENTRAL OREGON FROM REDMOND SOUTHWARD AND THE OCHOCO-JOHN
DAY HIGHLANDS AND THEN MOVING NORTHEAST THROUGH THE MOUNTAINS TO
WALLOWA COUNTY AND THE BLUE MOUNTAINS UNTIL AN HOUR OR TWO AFTER
SUNDOWN. A CUMULUS FIELD IS DEVELOPING AND THAT SHOULD LEAD TO
ISOLATED THUNDERSTORMS. DO NOT EXPECT ANY STORMS TO REACH SEVERE
LEVELS BUT COULD SEE BRIEF HEAVY RAIN...GUSTY WINDS...SMALL HAIL AND
FREQUENT LIGHTNING. STORMS YESTERDAY PUT OUT AS MUCH AS A HALF INCH
OF RAIN IN A FEW PLACES. PRECIPITABLE WATER IS LOWER TODAY THAN
YESTERDAY SO WOULD EXPECT LESS RAIN THAN YESTERDAY. THE OTHER EFFECT
OF THE DISTURBANCE IS TIGHTENING PRESSURE GRADIENTS AND WINDS HAVE
BEEN PICKING UP IN THE NORTH WITH 15 TO 25 MPH WINDS IN THE KITTITAS
VALLEY AND COLUMBIA GORGE AND 10 TO 20 MPH OVER MUCH OF THE REST OF
THE AREA.

TOMORROW A WEAK LOW WILL DROP INTO THE TROUGH AND STRETCH IT FURTHER
SOUTH. THIS WILL TURN THE FLOW OVER THE AREA MORE SOUTHERLY AND
SOMEWHAT LESS FAVORABLE FOR THUNDERSTORM DEVELOPMENT. TOMORROW WILL
QUITE POSSIBLY END UP BEING A BREAK IN THE THUNDERSTORMS BUT COULD
NOT QUITE BRING MYSELF TO COMPLETELY REMOVE THUNDERSTORMS. HAVE LEFT
A FRINGE OF A SLIGHT CHANCE OF THUNDERSTORMS FROM BEND SOUTHWARD AND
IN THE OCHOCO-JOHN DAY HIGHLANDS THEN NORTHEAST ALONG THE
ELKHORN...STRAWBERRY AND WALLOWA MOUNTAINS. ON THURSDAY THE TROUGH
WILL MOVE ASHORE OVER WESTERN OREGON AND WASHINGTON WITH THE FLOW
MOVING MOVE SOUTHWESTERLY. THIS WILL BE A FAIRLY ACTIVE DAY FOR
THUNDERSTORMS AND HAVE AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
EVERYWHERE EXCEPT THE COLUMBIA GORGE...THE YAKIMA AND KITTITAS
VALLEYS AND THE COLUMBIA BASIN. SHOULD HAVE THE HIGHEST CHANCE OF
THUNDERSTORMS FROM THE OCHOCO-JOHN DAY HIGHLANDS AND THE BLUE
MOUNTAINS EASTWARD. THUNDERSTORM ACTIVITY SHOULD LINGER OVERNIGHT IN
THE BLUE MOUNTAINS AND NORTHEAST OREGON. ON FRIDAY THE TROUGH WILL
BE CENTERED ALONG THE CASCADES BUT WILL BE LOSING AMPLITUDE AND
BECOME MORE SHALLOW. THIS SHOULD BE LESS FAVORABLE FOR THUNDERSTORMS
THAN THURSDAY SO HAVE PULLED BACK COVERAGE TO A SLIGHT CHANCE OF
THUNDERSTORMS IN CENTRAL OREGON FROM REDMOND SOUTHWARD AND IN THE
MOUNTAINS OF EASTERN OREGON. PERRY

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...MODELS IN GOOD AGREEMENT
IN KEEPING A LONG-WAVE TROUGH JUST OFF THE COAST THROUGH THE
PERIOD.  MINOR DIFFERENCES IN THE TIMINGS OF WEAK DISTURBANCES
MOVING THROUGH THE FORECAST AREA WILL LEAD TO UNCERTAIN SPECIFICITY.
DESPITE THIS UNCERTAINTY...LIMITED LOW/MID LEVEL MOISTURE WILL
CONFINE THE ISOLATED DIURNAL CONVECTION TO THE HIGHER PLATEAUS AND
MOUNTAINS. BY EARLY NEXT WEAK...THE LOWER ATMOSPHERE BECOMES TOO DRY
TO SUPPORT LITTLE IF ANY CONVECTION.  TEMPERATURES WILL REMAIN NEAR
TO SLIGHTLY BELOW NORMAL. EARLE

&&

.AVIATION...00Z TAFS...VFR CONDITIONS WILL OCCUR AT ALL TAF SITES.
HOWEVER...AN ISOLATED THUNDERSTORM MAY APPROACH THE VICINITY OF KRDM
THIS EVENING. WINDS WILL GENERALLY BE IN THE 10 TO 15 KT RANGE THIS
EVENING...EXCEPT KRDM WHICH WILL EXPERIENCE WINDS IN THE 15-20 KT
RANGE. WINDS WILL DECREASE OVERNIGHT. EARLE

&&

.FIRE WEATHER...BEGINNING TO HAVE CONCERNS ABOUT THE AMOUNT OF
POSSIBLE LIGHTNING THURSDAY AS A SHALLOW UPPER TROUGH CROSSES THE
REGION AROUND THE TIME OF PEAK HEATING. THERE ARE ENOUGH SUBTLE
DIFFERENCES BETWEEN MODELS REGARDING THE STRENGTH AND POSITION OF
THE TROUGH THAT DO NOT HAVE CONFIDENCE AT THIS TIME TO ISSUE A FIRE
WEATHER WATCH AND WILL WAIT FOR ANOTHER 12 HOURS WORTH OF RUNS TO
HOPE FOR GREATER CONSENSUS. A ROUGH AREA OF CONCERN FOR ABUNDANT
LIGHTNING RUNS FROM EASTERN FIRE ZONE 630 NORTHEAST TO INCLUDE THE
REMAINING MOUNTAIN ZONES ALONG WITH BAKER VALLEY. SLOWER STORM
MOTIONS ALONG WITH SOME UPPER LEVEL SUPPORT MAY RESULT IN A NOTABLE
CONCENTRATION OF LIGHTING UNDER A WORST CASE SCENARIO. THE SLOWER
MOTIONS WILL AID IN RAINFALL REACHING THE GROUND, HOWEVER. REMAINING
AREAS MAY SEE ISOLATED ACTIVITY WITH THE MAIN QUESTIONS REVOLVING
AROUND WHETHER A SOUTH-SOUTHWESTERLY STORM MOTION WILL PREVAIL OR IF
A NORTHWESTERLY MOTION WILL PREVENT ACTIVITY COMING OFF THE OREGON
CASCADES. THE LOWER BASIN AREAS MAY SEE ISOLATED ACTIVITY BUT SOME
MODEL SOLUTIONS ALSO SHOW A MODERATE CAP AT MIDLEVELS.

IF DETERMINED NECESSARY, WILL LIKELY ISSUE FIRE WEATHER WATCHES
WEDNESDAY MORNING. /JBONK

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  56  89  57  90 /  10  10  10  20
ALW  61  90  61  92 /  10  10  10  20
PSC  58  91  59  93 /  10   0  10  10
YKM  56  87  58  90 /  10   0  10  10
HRI  58  91  59  92 /  10   0  10  10
ELN  56  87  57  90 /  10   0  10  10
RDM  48  87  51  86 /  10  10  10  20
LGD  54  87  54  87 /  20  10  20  30
GCD  53  88  53  86 /  20  10  20  30
DLS  59  89  61  88 /   0   0  10  10

&&

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

THREAT INDEX
WEDNESDAY : GREEN
THURSDAY : GREEN
FRIDAY : 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

83/81/81/87

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1201 PM PDT TUE AUG 2 2011

UPDATED THUNDERSTORM COVERAGE TODAY...WEDNESDAY AND THURSDAY

ORZ041-042-044-049-050-502-503-505>509-WAZ024-026>030-520-521-
031215-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-WALLOWA COUNTY-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-JOHN DAY BASIN-OCHOCO-
JOHN DAY HIGHLANDS-
FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS OF OREGON-
FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS OF OREGON-
EAST SLOPES OF THE OREGON CASCADES-
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 OF WASHINGTON-
EAST SLOPES OF THE WASHINGTON CASCADES-SIMCOE HIGHLANDS-
1201 PM PDT TUE AUG 2 2011

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS
     NORTHWEST BLUE MOUNTAINS OF WASHINGTON, NORTH CENTRAL OREGON,
     EAST SLOPES OF THE OREGON CASCADES, GRANDE RONDE VALLEY,
     WALLOWA COUNTY, NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN
     BLUE MOUNTAINS OF OREGON, JOHN DAY BASIN, OCHOCO-JOHN DAY
     HIGHLANDS

A WEAK DISTURBANCE WILL MOVE THROUGH THE AREA THIS AFTERNOON AND
EVENING...POSSIBLY TRIGGERING ISOLATED TO SCATTERED THUNDERSTORMS
FROM CENTRAL OREGON THROUGH THE NORTHEAST MOUNTAINS. ALTHOUGH SEVERE
STORMS ARE NOT EXPECTED...ANY STORMS THAT DO DEVELOP COULD
POTENTIALLY PRODUCE SMALL HAIL...GUSTY WINDS AND/OR LOCALLY HEAVY
RAIN.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS WEDNESDAY
     NORTHWEST BLUE MOUNTAINS OF WASHINGTON, EAST SLOPES OF THE
     OREGON CASCADES, GRANDE RONDE VALLEY, WALLOWA COUNTY, SOUTHERN
     BLUE MOUNTAINS OF OREGON, JOHN DAY BASIN, OCHOCO-JOHN DAY
     HIGHLANDS

THUNDERSTORMS THURSDAY
     EAST SLOPES OF THE WASHINGTON CASCADES, FOOTHILLS OF THE BLUE
     MOUNTAINS OF WASHINGTON, NORTHWEST BLUE MOUNTAINS OF
     WASHINGTON, NORTH CENTRAL OREGON, EAST SLOPES OF THE OREGON
     CASCADES, SIMCOE HIGHLANDS, GRANDE RONDE VALLEY, WALLOWA
     COUNTY, FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS OF OREGON,
     NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF
     OREGON, FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS OF OREGON,
     JOHN DAY BASIN, OCHOCO-JOHN DAY HIGHLANDS

THE SOUTHWEST FLOW WILL PERSIST WITH MOISTURE CONTINUING TO BE
PULLED NORTHWARD INTO SOUTHEAST PORTIONS OF THE FORECAST AREA. THIS
WILL RESULT IN MAINLY AFTERNOON AND EVENING THUNDERSTORMS EACH DAY
THROUGH THE WEEK. THURSDAY WILL HAVE THE GREATEST POTENTIAL FOR
THUNDERSTORMS AS AN UPPER TROUGH MOVES ACROSS THE REGION. A TROUGH
PATTERN IS EXPECTED TO LINGER OVER THE PACIFIC NORTHWEST INTO THE
WEEKEND...WITH THE POTENTIAL FOR THUNDERSTORMS LIKELY TO PERSIST AS
WELL.

.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.