Damaging Wind in Oregon, May 19, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PDT WED MAY 19 2010

.SHORT TERM...THE LATEST RADAR WAS SHOWING A LARGE AREA OF PCPN OVER
WESTERN OREGON THAT WAS MOVG ACROSS THE WA/OR CASCADES. THE PCPN
WILL CONTINUE MOVG EAST INTO THE REMAINDER OF THE AREA AND INCREASE
IN COVERAGE TONIGHT. SNOW LEVELS WILL FALL OVERNIGHT BUT SHOULD
LOWER TO AROUND 4500FT BY TOMORROW MORNING. THE BULK OF THE MOISTURE
AND COLD FRONT SHOULD MOVE EAST OF THE REGION BY THURSDAY. HOWEVER
SHOWERS SHOULD PERSIST ESPECIALLY IN AN UPSLOPE WESTERLY FLOW IN THE
AREA MOUNTAINS. AFTERNOON HIGH TEMPS WILL BE COOLER BY AS MUCH AS
15 DEGREES. ANOTHER STORM SYSTEM TAKES AIM ON THE PACNW FRIDAY. MID
LEVEL LOW PRESSURE IS EXPECTED TO MOVE INTO WA/OR WITH SHOWERS
DEVELOPING ONCE AGAIN ACROSS THE AREA THAT SHOULD CONTINUE INTO
FRIDAY NIGHT. SNOW LEVELS LOWER EVEN MORE AND SOME FROZEN PCPN IS
POSSIBLE ACROSS MEH AND TOLLGATE FRIDAY NIGHT.

WIND ADVISORIES HAVE BEEN POSTED FOR THE YAKIMA VALLEY...EAST SLOPES
OF THE SOUTHERN WA CASCADES...THE EASTERN COLUMBIA RIVER
GORGE...LOWER COLUMBIA BASIN AND BLUE MTN FOOTHILLS IN EFFECT FOR 5
PM THROUGH 10 PM THIS EVENING.  WINDS ALOFT ARE INCREASING AHEAD OF
THE FRONT...AS EVIDENT BY SOME OF THE RIDGETOP WINDS IN CENTRAL
OREGON.  THE FAST MOVING COLD FRONT WILL HAVE THE COMBINATION OF A
TIGHT PRESSURE GRADIENT AND STRONG WINDS ALOFT TO BRING A 3-5 HOUR
PERIOD OF VERY WINDY CONDITIONS AND GUSTS TO 50-55 MPH. SURFACE
WINDS WILL DECOUPLE FROM WINDS ALOFT OVERNIGHT...DIMINISHING OVER
MOST OF THE AREA BY EARLY THURSDAY MORNING.  85

.LONG TERM...SATURDAY THROUGH WEDNESDAY...MODELS CONTINUE TO BE IN
BROAD AGREEMENT AS TO THE PATTERN OVER THE PACIFIC NORTHWEST OVER
THE WEEKEND AND EARLY NEXT WEEK BUT DIFFER AS TO THE DETAILS.
INITIALLY MODELS HAVE AN UNSEASONABLY STRONG UPPER LOW OVER THE AREA
WHICH WILL GIVE US A SLIGHT CHANCE OF SHOWERS IN THE COLUMBIA BASIN
AND A CHANCE EVERYWHERE ELSE. WHILE THE COLUMBIA BASIN SHOULD MAKE
IT INTO THE LOW 60S...THE REST OF THE AREA WILL STRUGGLE TO MAKE IT
INTO THE LOW 50S AND SNOW LEVELS WILL BE AT 3500 TO 4000 FEET WHICH
WILL GIVE THE MOUNTAINS SOME SNOW SHOWERS BUT ALSO AREAS SOUTH OF
WEST OF BEND MAY GET A RAIN/SNOW MIX. CURRENTLY PRECIPITATION
AMOUNTS ARE NOT EXPECTED TO BE TOO SUBSTANTIAL SO SNOW SHOULD NOT
REACH ADVISORY LEVELS...BUT THIS COULD CHANGE DURING THE NEXT DAY OR
TWO. SHOWERS SHOULD TAPER OFF SATURDAY NIGHT AND SUNDAY AS THE LOW
SINKS TO THE SOUTHWEST. SNOW LEVELS WILL RISE SUNDAY TO 4500 TO 5000
FEET AS TEMPERATURES GO UP 3 TO 5 DEGREES. BY MONDAY THE GFS HAS A
LOW MOVING ASHORE OVER THE AREA AND KEEPS A DEEP TROUGH THROUGH
TUESDAY MORNING BEFORE REFORMING IT OFFSHORE TUESDAY AFTERNOON
THROUGH WEDNESDAY. THE ECMWF HAS THE LOW STILL OFF OF THE CENTRAL
BRITISH COLUMBIA COAST ON MONDAY WITH A SHALLOW TROUGH THROUGH
TUESDAY NIGHT BEFORE BUILDING A STRONGER TROUGH OFFSHORE TUESDAY
THROUGH WEDNESDAY. FAVOR THE ECMWF BUT GIVEN THE
DISAGREEMENT....KEPT A SLIGHT CHANCE OF SHOWERS IN THE LOWER
ELEVATIONS WITH A CHANCE IN THE MOUNTAINS SUNDAY NIGHT THROUGH
WEDNESDAY. PERRY

&&

.AVIATION...PREVIOUS DISCUSSION...18Z TAFS...STRONG COLD FRONT TO
MOVE THROUGH TAF SITES WITH INCREASING SW-W-NW WINDS AND GUSTS 30-40
KTS. FROPA EXPECTED 22Z KDLS...23Z KRDM...00Z KPSC KYKM...01Z KPDT
KALW. -SHRA AND ISOLATED -TSRA EXPECTED WITH FROPA...BUT CONDITIONS
REMAIN VFR. LOW LEVEL WIND SHEAR OF +/- 15 KTS WILL BE POSSIBLE AT
TAF SITES THROUGH 06Z THIS EVENING...ESPECIALLY AT KRDM. HULL/PERRY

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  42  57  40  55 /  60  20  30  60
ALW  43  59  41  57 /  60  20  30  60
PSC  46  62  41  60 /  50  20  20  40
YKM  41  57  36  54 /  50  20  20  40
HRI  44  60  41  60 /  50  20  20  40
ELN  42  56  37  55 /  50  30  20  40
RDM  34  54  33  52 /  60  30  30  30
LGD  41  52  35  50 /  70  40  40  50
GCD  39  54  36  50 /  60  30  30  50
DLS  46  60  40  57 /  50  30  20  60

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 10 PM PDT THIS
EVENING      ORZ041-044-501.

WA...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 10 PM PDT THIS
EVENING      WAZ024-027>029-502.

&&

THREAT INDEX
THURSDAY : YELLOW
FRIDAY : GREEN
SATURDAY : 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

97/83/83

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
915 AM PDT WED MAY 19 2010

UPDATED FOR WIND ADVISORY AND THUNDERSTORM INFORMATION

ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-201415-
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 OF WASHINGTON-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
915 AM PDT WED MAY 19 2010

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

STRONG WIND

     EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON, 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, LOWER
     COLUMBIA BASIN OF OREGON, FOOTHILLS OF THE BLUE MOUNTAINS OF
     OREGON

ISOLATED THUNDERSTORMS...ALL OF FORECAST AREA WHICH INCLUDES....

     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, KITTITAS
     VALLEY, NORTHWEST BLUE MOUNTAINS OF WASHINGTON, NORTH CENTRAL
     OREGON, CENTRAL OREGON, GRANDE RONDE VALLEY, WALLOWA COUNTY,
     NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF
     OREGON, NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES,
     JOHN DAY BASIN, OCHOCO-JOHN DAY HIGHLANDS, EAST SLOPES OF THE
     SOUTHERN CASCADES OF WASHINGTON, 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, LOWER COLUMBIA BASIN OF
     OREGON, FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON

A STRONG AND FAST MOVING COLD FRONT WILL BRING INCREASING WINDS,
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO THE FORECAST AREA.
VERY WINDY CONDITIONS ARE EXPECTED BETWEEN 5 PM AND 10 PM IN THE
AREAS LISTED ABOVE...AND A WIND ADVISORY HAS BEEN ISSUED.  FOR
DETAILS...REFER TO THE NWS PRODUCT PDXNPWPDT.

ALTHOUGH ONLY ISOLATED THUNDERSTORMS ARE EXPECTED TODAY, SOME STORMS
MAY BRING GUSTY WINDS AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

UNSETTLED WEATHER WILL CONTINUE INTO NEXT WEEK AS A SERIES OF LOW
PRESSURE SYSTEMS MOVE THROUGH THE REGION...BRINGING MORE SHOWERS AND
POSSIBLY THUNDERSTORMS ALONG WITH BREEZY TO WINDY CONDITIONS AT
TIMES. IN ADDITION...TEMPERATURES WILL COOL TO BELOW NORMAL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY FOR STRONG WINDS AND
THUNDERSTORMS TODAY.

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.