High Wind in Washington, June 21, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
409 PM PDT TUE JUN 21 2005

UPDATED AVIATION SECTION

.SHORT TERM...THIS AFTERNOON THROUGH THURSDAY NIGHT...MAIN CONCERN
IS STILL A POTENTIAL FOR ISOLATED TO SCATTERED THUNDERSTORMS
DEVELOPING LATE THIS AFTERNOON AND THIS EVENING...BEGINNING IN
CENTRAL AND NORTH CENTRAL OREGON AND THEN DEVELOPING AND MOVING
NORTHEAST ACROSS NORTHEAST OREGON INTO THE LOWER COLUMBIA BASIN. AN
UPPER LEVEL LOW PRESSURE SYSTEM OFF THE SOUTHERN OREGON COAST WILL
MOVE NORTHEAST THIS AFTERNOON AND TONIGHT AND SPIN OFF AN UPPER
LEVEL SHORT WAVE IN THE MID AND UPPER ATMOSPHERE THAT WILL PROVIDE
DYNAMIC LIFT. IN ADDITION...AN UPPER LEVEL JET STREAK WILL MOVE
NORTHEAST THROUGH THE FORECAST AREA THIS AFTERNOON PROVIDING STRONG
DEEP LAYER VERTICAL SHEAR THAT WILL CREATE AN ENVIRONMENT THAT IS
SOMEWHAT FAVORABLE FOR A FEW STRONG THUNDERSTORMS WITH BETTER
ORGANIZATION AND SUSTAINED UPDRAFTS TO DEVELOP. CANNOT RULE OUT THE
POSSIBILITY THAT ANY STRONG THUNDERSTORMS THAT OCCUR COULD BECOME
SEVERE WITH LARGE HAIL AND DAMAGING GUSTY WINDS. WE WILL CONTINUE TO
CLOSELY MONITOR THE SITUATION FOR THUNDERSTORMS FOR THE REMAINDER OF
THIS AFTERNOON AND THIS EVENING.

A MARINE PUSH WILL COMMENCE BY LATE THIS AFTERNOON IN THE LOWER
COLUMBIA BASIN...THE FOOTHILLS OF THE BLUE MOUNTAINS AND THE EASTERN
COLUMBIA RIVER GORGE DUE TO INCREASING PRESSURE GRADIENTS FOR BREEZY
TO WINDY CONDITIONS SPREADING EASTWARD ACROSS THE FORECAST AREA
STARTING LATE THIS AFTERNOON AND CONTINUING THROUGH MOST OF THIS
EVENING.

THE AFOREMENTIONED UPPER LEVEL LOW WILL OPEN UP TONIGHT ALONG THE
COAST AND THEN LIFT NORTHWARD ACROSS WESTERN WASHINGTON
WEDNESDAY. THIS TRACK WILL LIMIT CHANCES FOR SHOWERS TO THE
WASHINGTON CASCADES ON WEDNESDAY.  POLAN

.LONG TERM...FRIDAY THROUGH TUESDAY...AN UPPER TROUGH WILL DIG ALONG
THE WEST COAST FRIDAY THROUGH SUNDAY....WITH ENERGY MOVING AROUND
THE LOW TRIGGERING SHOWERS AND DAYTIME THUNDERSTORMS. THIS TROUGH
WILL KEEP TEMPERATURES AT OR SLIGHTLY BELOW SEASONAL VALUES.
PRECIPITATION WILL BE LIMITED TO A FEW MOUNTAIN AREAS FRIDAY WITH
LIMITED MOISTURE...BUT SPREAD OVER ALL THE CWA SATURDAY AND SUNDAY.
THUNDERSTORMS WILL EXTEND FROM CENTRAL OREGON AND THE OCHOCOS TO THE
NORTHEAST OREGON MOUNTAINS SATURDAY AND SUNDAY AFTERNOON WHEN
DAYTIME HEATING ENHANCES THE INSTABILITY ASSOCIATED WITH THE TROUGH.
MONDAY THE TROUGH WILL MOVE OVER EASTERN WASHINGTON AND OREGON. SOME
LINGERING INSTABILITY WILL TRIGGER SHOWERS ON TUESDAY.   COONFIELD

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS.
ISOLATED CONVECTION HAS STARTED OVER OREGON AND SOUTHEAST
WASHINGTON. IN VICINITY OF THUNDERSTORMS THERE WILL BE GUSTY
WINDS...HAIL AND CEILINGS 7000-10000 FT AGL. ALL TAF SITES MAY SEE A
THUNDERSTORM PASS NEAR THEIR VICINITY. WINDS AT KDLS ARE CURRENTLY
RUNNING 25-30 KTS. 15-30 KT WINDS WILL SPREAD OVER THE
COLUMBIA BASIN TO KPSC...KYKM...KPDT...AND KALW BETWEEN 22-01Z.
THUNDERSTORM ACTIVITY WILL HAVE TO BE MONITORED AT KPSC FOR THE
POTENTIAL OF AVIATION WEATHER WARNING CRITERIA BEING MET (LIGHTNING
AND/OR HAIL MOVING ACROSS THE FIELD). KRDM...KDLS...KYKM...KPDT AND
KALW WILL ALSO NEED TO BE CLOSELY MONITORED UNTIL 04Z FOR
STORMS POSSIBLY PRODUCING LARGE HAIL AND STRONG WINDS.  76

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  57  82  52  80 /  30  20  10   0
ALW  62  82  55  82 /  30  20  10   0
PSC  60  86  52  85 /  30  10  10   0
YKM  57  80  50  83 /  30  10  10   0
HRI  59  84  52  84 /  30  10  10   0
ELN  56  75  49  83 /  30  20  10  10
RDM  45  77  40  79 /  30  10  10   0
LGD  55  80  50  80 /  30  20  10  10
5J0  51  81  47  81 /  30  10  10  10
DLS  60  79  55  85 /  30  10  10   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY THROUGH 10 PM FOR ZONE 41 (EASTERN COLUMBIA
     GORGE).
WA...WIND ADVISORY THROUGH 10 PM FOR ZONE 24 (EASTERN COLUMBIA
GORGE).
&&

TI:RGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
99/76/76

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1130 AM PDT TUE JUN 21 2005

WAZ024>030-ORZ041>050-221215-
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 JUN 21 2005

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

.DAY ONE...TODAY AND TONIGHT

SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE AFTERNOON/EVENING
     KITTITAS VALLEY, YAKIMA VALLEY, LOWER COLUMBIA BASIN OF
     WASHINGTON, FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON,
     NORTHWEST BLUE MOUNTAINS, 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

STRONG THUNDERSTORMS IN THE AFTERNOON/EVENING
     EAST COLUMBIA RIVER GORGE OF WASHINGTON, EAST SLOPES OF THE
     SOUTHERN CASCADES, EASTERN COLUMBIA RIVER GORGE OF OREGON

AN UPPER LEVEL LOW OFF THE NORTHERN CALIFORNIA COAST WILL BEGIN TO
MOVE NORTH-NORTHEAST TODAY SENDING A SHORTWAVE ACROSS THE REGION
THIS AFTERNOON. MOISTURE...INSTABILITY...AND WIND SHEAR IN THE MID
LEVELS OF THE ATMOSPHERE WILL CREATE AN ENVIRONMENT FAVORABLE FOR
THE DEVELOPMENT OF STRONG TO SEVERE THUNDERSTORMS ACROSS THE AREA
THIS AFTERNOON AND EARLY EVENING. THE STORM PREDICTION CENTER HAS
PLACED MOST OF NORTHEAST OREGON AND SOUTHEAST WASHINGTON IN THE
SLIGHT RISK CATEGORY FOR SEVERE STORMS. THE MAIN THREAT WILL BE
GUSTY WINDS AND HAIL.

ADDITIONALLY...A STRONG PRESSURE GRADIENT WILL SET UP AND PUSH
MARINE AIR THROUGH THE COLUMBIA GORGE AND OVER THE CASCADES. THIS
WILL LEAD TO INCREASING PRESSURE GRADIENTS LATE THIS AFTERNOON AND
THIS EVENING FOR BREEZY TO WINDY CONDITIONS IN THE EASTERN COLUMBIA
RIVER GORGE...THE LOWER COLUMBIA BASIN AND THE FOOTHILLS OF THE BLUE
MOUNTAINS. SUSTAINED WESTERLY WINDS OF 20 TO 30 MPH WITH GUSTS TO 40
MPH ARE EXPECTED IN THE EASTERN COLUMBIA RIVER GORGE...THE LOWER
COLUMBIA BASIN AND THE FOOTHILLS OF THE BLUE MOUNTAINS BEGINNING
LATE THIS AFTERNOON AND CONTINUING THROUGH MOST OF THIS EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS WEDNESDAY
     NORTHWEST BLUE MOUNTAINS, BLUE MOUNTAINS, OCHOCO-JOHN DAY
     HIGHLANDS, GRANDE RONDE VALLEY, WALLOWA COUNTY

AVAILABLE MOISTURE AND MARGINAL INSTABILITY WILL ALLOW ISOLATED
THUNDERSTORMS TO DEVELOP WEDNESDAY AFTERNOON ACROSS THE MOUNTAINS OF
CENTRAL AND NORTHEAST OREGON.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE LIKELY THIS AFTERNOON AND THIS EVENING
FOR SCATTERED THUNDERSTORMS BECOMING STRONG WITH ISOLATED SEVERE
THUNDERSTORMS POSSIBLE.

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.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
334 PM PDT TUE JUN 21 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0328 PM     HAIL             4 WNW TOLLGATE          45.79N 118.15W
06/21/2005  0.88 INCH        UMATILLA           OR   TRAINED SPOTTER

            THUNDERSTORM MOVED OVER AREA...INITIALLY PRODUCING HEAVY
            RAIN. HAIL STARTED OUT THE SIZE OF DIMES...AND INCREASED
            TO NICKEL SIZE BY 328 PM.

&&

CP