Hail in Oregon, May 29, 2009

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
425 PM PDT FRI MAY 29 2009

UPDATED AVIATION DISCUSSION

.SHORT TERM...HIGH PRESSURE WAS OVER N NEVADA AND PROVIDING OUR WARM
TEMPERATURES FOR TODAY. LATEST RADAR WAS SHOWING CONVECTION FIRING
ALONG THE SOUTHERN PORTIONS OF THE AREA AND EXTENDS NE INTO THE BLUE
AND WALLOWA MTNS. THIS IS IN RESPONSE TO ABOVE NORMAL TEMPS AND MID
LEVEL MOISTURE THAT WAS RAPPING AROUND THE HIGH AND INTO OUR AREA.
SOME OF THE STORMS MAY BECOME STRONG TODAY WITH THE THREAT OF HAIL A
POSSIBILITY MAINLY SOUTH OF THE OREGON/WA STATE LINE. THE GFS AND
NAM WERE IN AGREEMENT WITH KEEPING THE INSTABILITY OVER MOST OF THE
AREA OVERNIGHT. HOWEVER SOME DRIER AIR WORKS ITS WAY INTO PORTIONS
OF THE REGION FROM THE WEST AND INDICATED THIS IN THE FORECAST
OVERNIGHT.

BY SATURDAY MID LEVEL MOISTURE REMAINS OVER CENTRAL OREGON AND INTO
THE BLUES/WALLOWAS AND WILL LEAVE POPS IN THE FORECAST ACROSS THIS
AREA. ONCE AGAIN COMBINING THE MID LEVEL MOISTURE PLUME WITH ABOVE
NORMAL TEMPERATURES WILL PRODUCE AFTERNOON AND EVENING
THUNDERSTORMS. A SUBTLE COOL FRONT PASSING THROUGH THE AREA SATURDAY
NIGHT MAY LOWER AFTN TEMPERATURES SOME ON SUNDAY BUT THEY WILL STILL
REMAIN ABOVE NORMAL. MID LEVEL MOISTURE REMAINS OVER THE SOUTHERN
PORTIONS OF THE AREA THAT INCLUDES CENTRAL OREGON EASTWARD TO SENECA
AND THE BLUE/WALLOWA MTNS SUNDAY. THUS SHOWERS AND THUNDERSTORMS ARE
POSSIBLE ACROSS THIS AREA AGAIN.

.LONG TERM...MONDAY THROUGH FRIDAY...MID RANGE DATA ARE NOW TRYING
TO CONVERGE ON A REX BLOCK TYPE SOLUTION AS THE PATTERN FOR THIS
PERIOD. AS SUCH WE WOULD SEE NORTHERLY FLOW ALOFT OVER THE NORTHERN
HALF OF THE PACNW WITH A CONVERGENT EASTERLY FLOW OVER CENTRAL AND
SOUTHERN OREGON. THUS CONDITIONS WOULD BE FAIR AND DRY ACROSS
WASHINGTON AND EXTREME NORTHERN OREGON WITH SHOWERS AND
THUNDERSTORMS POSSIBLE OVER CENTRAL OREGON. AT THIS TIME CONFIDENCE
REMAINS LOW AS TO WHETHER THIS PATTERN WILL INDEED FORM...ESPECIALLY
BEYOND MONDAY. AT THIS TIME WILL GO ALONG WITH THE REX BLOCK PATTERN
FOR MONDAY...AND HAVE INDICATED SLIGHT CHANCE SHOWERS AND/OR
THUNDERSTORMS OVER OUR CENTRAL OREGON ZONES AND DRIED OUT ALL OTHER
AREAS. FOR THE REMAINDER OF THE PERIOD ONLY SLIGHT CHANGES WERE
MADE TO THE CURRENT FORECASTS DUE TO THE CONTINUED UNCERTAINTY. 90

&&

.AVIATION...00Z TAFS...VFR CONDITIONS WILL PERSIST DURING THE NEXT
24 HOURS. THE MAIN CONCERN THROUGH THIS EVENING WILL BE THE LOCATION
AND TRACK OF THUNDERSTORMS. WILL INDICATE VCTS AT KDLS...KRDM...
KPSC...KALW AND KPDT THROUGH THIS EVENING...AS THESE SITES HAVE THE
BEST CHANCES TO SEE THUNDER. SPECIFIC OCCURRENCE TIMES OF A STORM
OVER ANY ONE OF THESE SITES IS STILL RELATIVELY UNCERTAIN...BUT THEY
COULD SEE AT LEAST LIGHT RAIN SHOWERS BETWEEN 00 AND 04 UTC AS
STORMS PASS NEAR BY. AT KYKM...WILL CONTINUE TO INDICATE LESSER
CHANCES WITH A CB REMARK ATTACHED TO LOWER CLOUD DECKS INTO THE
EVENING. THE THUNDERSTORM THREAT SHOULD WIND DOWN AROUND MIDNIGHT...
THEN MAY REDEVELOP OVER CENTRAL OREGON SATURDAY AFTERNOON. FOR NOW
WILL INDICATE A SLIGHT THREAT OF THUNDER AT KRDM WITH CB REMARKS
LATE IN THIS PERIOD. WINDS WILL MAINLY BE UNDER 15 KTS...THOUGH
GUSTS OF UP TO 30 KTS CAN BE EXPECTED NEAR ANY THUNDERSTORMS. 90

&&

.HYDROLOGY...A FLOOD ADVISORY FOR MINOR FLOODING CONTINUES TO BE IN
EFFECT THROUGH 415 PM PDT TODAY FOR THE YAKIMA RIVER NEAR THE ELK
MEADOWS SUBDIVISION IN CENTRAL KITTITAS COUNTY. DETAILS ON THIS CAN
BE FOUND IN THE PRODUCT PDXFLSPDT. A RIVER STATEMENT (PDXRVSPDT)
CONTINUES FOR THE NACHES RIVER NEAR CLIFFDELL AND NACHES...AND THE
YAKIMA RIVER AT UMTANUM. THESE RIVERS WILL CONTINUE TO RUN HIGH BUT
ARE EXPECTED TO REMAIN BELOW FLOOD STAGE AT THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  57  89  57  84 /  20  10  10  10
ALW  59  90  55  83 /  30  10  10  10
PSC  58  94  54  90 /  20   0   0   0
YKM  55  90  52  88 /  20   0   0   0
HRI  56  93  54  86 /  20  10  10  10
ELN  56  88  50  85 /  20   0   0   0
RDM  50  87  49  85 /  30  20  20  20
LGD  52  84  51  83 /  30  20  20  20
GCD  52  85  53  81 /  30  20  20  20
DLS  57  91  55  89 /  10   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...FLOOD ADVISORY IN EFFECT FOR CENTRAL KITTITAS COUNTY NEAR ELK
     MEADOWS SUBDIVISION UNTIL 415 PM PDT FRIDAY.
&&

TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
97/90/90

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
330 PM PDT FRI MAY 29 2009

UPDATED FOR EXTENSION OF FLOOD ADVISORY

ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-301415-
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-
330 PM PDT FRI MAY 29 2009

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

.DAY ONE...TONIGHT

FLOODING
     KITTITAS VALLEY

THUNDERSTORMS
     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, 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,
     NORTHWEST BLUE MOUNTAINS, 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

A FLOOD ADVISORY HAS BEEN EXTENDED UNTIL 415 PM SATURDAY FOR CENTRAL
KITTITAS COUNTY. ALONG THE YAKIMA RIVER IN THE VICINITY OF THE ELK
MEADOWS SUBDIVISION...6 MILES NORTHWEST OF CLE ELUM...THE WATER
LEVEL HAS DROPPED. HOWEVER...RESIDENTS IN THE ELK MEADOWS
AREA...REPORTED THAT THE YAKIMA RIVER CONTINUES TO BE ABOVE BANKFULL
IN LOCATIONS THROUGH THE HOUSING AREA WITH SEVERAL ROADS STILL
COVERED BY WATER. THE FLOOD ADVISORY CAN BE FOUND UNDER THE PRODUCT
PDXFLSPDT.

SOUTHERLY FLOW ALOFT WILL BRING MOIST UNSTABLE AIR INTO THE REGION.
AS A RESULT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS
OREGON AND WASHINGTON THIS AFTERNOON AND EVENING. SOME OF THE STORMS
MAY BECOME STRONG AND PRODUCE HAIL...GUSTY WINDS TO 45
MPH...FREQUENT LIGHTNING...BRIEF HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

FLOODING
     KITTITAS VALLEY

THUNDERSTORMS SATURDAY
     NORTHWEST BLUE MOUNTAINS, CENTRAL OREGON, GRANDE RONDE VALLEY,
     WALLOWA COUNTY, NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN
     BLUE MOUNTAINS OF OREGON, JOHN DAY BASIN, OCHOCO-JOHN DAY
     HIGHLANDS

THE YAKIMA RIVER WILL CONTINUE TO RUN HIGH DUE TO SNOW MELT.
RELEASES FROM THE UPSTREAM RESERVOIRS WILL REMAIN NEARLY STEADY
THROUGH THE WEEKEND. THE FLOOD ADVISORY HAS BEEN EXTENDED TO
SATURDAY AFTERNOON.

SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE IN CENTRAL
AND EASTERN OREGON ON SATURDAY. NORTHWESTERLY FLOW WILL BRING DRIER
CONDITIONS TO THE REGION ON SUNDAY AND MONDAY. UNSETTLED WEATHER
WILL RETURN ON TUESDAY AS A LOW PRESSURE SYSTEM IMPACTS THE WEST
COAST.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED MAINLY OVER CENTRAL OREGON AND
OVER THE BLUE AND WALLOWA MOUNTAINS THIS AFTERNOON AND EVENING FOR
HAIL NEARING AN INCH.

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.

VP