Hail and Damaging Winds in Oregon, June 29 to 30, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
152 PM PDT SUN JUN 29 2008

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT...AN UPPER LEVEL RIDGE
IS LOCATED NEAR THE WASHINGTON-OREGON-IDAHO BORDER THIS AFTERNOON.
THE RIDGE AXIS WILL DRIFT SLOWLY EAST THROUGH MONDAY NIGHT.
SUBSIDENCE FROM THE RIDGE WILL KEEP TEMPERATURES HOT OVER EASTERN
WASHINGTON AND OREGON TONIGHT AND MONDAY. AS THE RIDGE DRIFTS EAST
MONDAY THERE WILL BE LESS SUBSIDENCE..BUT A WARM START. THE END
RESULT WILL BE TEMPERATURES A LITTLE COOLER THAN TODAY. A HEAT
ADVISORY REMAINS IN EFFECT THROUGH MONDAY FOR THE LOWER COLUMBIA
BASIN...COLUMBIA RIVER GORGE...JOHN DAY BASIN...THE FOOTHILLS OF THE
BLUES...EAST SLOPES OF SOUTHERN WASHINGTON CASCADES...AND THE YAKIMA
AND KITTITAS VALLEYS.

EASTERN WASHINGTON AND OREGON WILL REMAIN IN THE SOUTHERLY FLOW ON
THE BACKSIDE OF THE RIDGE THROUGH MONDAY NIGHT. THIS WILL BRING
INCREASING MOISTURE AND INSTABILITY INTO THE AREA. A FEW CUMULUS
BUILDUPS ARE SPREADING NORTH IN CENTRAL OREGON...THE OCHOCO-JOHN DAY
HIGHLANDS...AND ALONG THE OREGON CASCADES. THESE WILL DEVELOP INTO
THUNDERSTORMS LATER TODAY AS HEATING INCREASES ENOUGH TO BREAK THE
CAP. A DISTURBANCE WILL MOVE NORTH ALONG THE CASCADES THIS EVENING
AND SPREAD THE THUNDERSTORM THREAT NORTH AND EAST.  ELEVATED
INSTABILITY WILL PERSIST OVERNIGHT ALLOWING THE THUNDERSTORM THREAT
TO CONTINUE OVERNIGHT. MONDAY A DISTURBANCE WILL ROTATE AROUND A LOW
OFF THE CALIFORNIA COAST INTO EASTERN OREGON AND WASHINGTON. THIS
WILL SPREAD ENOUGH INSTABILITY AND MOISTURE FOR THUNDERSTORMS TO
OCCUR THROUGHOUT THE AREA. A WEAK MARINE PUSH WILL MOVE EAST OF THE
CASCADES MONDAY EVENING. THIS WILL STABILIZE THE LOWER ATMOSPHERE
NEAR THE CASCADES AND COLUMBIA RIVER GORGE TO DECREASE THE
THUNDERSTORM THREAT...BUT IT WILL ENHANCE THREAT IN THE LOWER
COLUMBIA BASIN EAST OF THE TRI-CITIES AND FOOTHILLS OF THE BLUES.
ANOTHER DISTURBANCE WILL MOVE FROM HARNEY COUNTY OREGON NORTHWARD TO
FRANKLIN COUNTY WASHINGTON MONDAY NIGHT AND THE ASSOCIATED ELEVATED
INSTABILITY WILL KEEP THUNDERSTORMS GOING ALL NIGHT IN THE EASTERN
AREAS.  COONFIELD

.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT...WEATHER PATTERN PRETTY
MUCH REMAINS UNCHANGED DURING THIS TIME WITH A HIGH AMPLITUDE RIDGE
OF HIGH PRESSURE OVER THE INLAND PACIFIC NORTHWEST AND A DEEP TROUGH
OFF THE WEST COAST. THIS PLACES THE FORECAST REGION IN A SOUTHERLY
FLOW WITH WEAK IMPULSES KICKING OUT OF THE TROUGH AIDING IN
THUNDERSTORM POTENTIALLY NEARLY EVERY DAY. DAILY LOCATION OF
THUNDERSTORMS WILL VARY SOMEWHAT BUT OVERALL A GOOD THUNDERSTORM
PATTERN. TEMPERATURES WILL ALSO TEND TO REMAIN ABOVE NORMAL IN THIS
PATTERN. MODELS ARE INDICATING THAT THE HIGH PRESSURE WILL SHIFT
EASTWARD LATE FRIDAY AND SATURDAY. IF THIS HAPPENS THERE WILL BE
SOME COOLING AND A DECREASE IN THUNDERSTORM ACTIVITY.

SATURDAY THROUGH SUNDAY EVENING...LOOKS TO BE A FAIRLY NICE WEEKEND
AS THE UPPER LEVEL RIDGE CONTINUES TO BREAK DOWN...THIS WILL START A
TRANSITION INTO WESTERLY FLOW ALOFT.  FORECASTED TEMPERATURES WILL
STILL BE VERY WARM IN THE LOWER ELEVATIONS...HOWEVER...A 7 TO 10
DEGREE DROP WILL PROVIDE MORE PLEASANT CONDITIONS THAN EARLIER IN
THE WEEK. NO PRECIPITATION IS EXPECTED DURING THIS TIME PERIOD AS
THE ATMOSPHERE BECOMES MORE STABLE.  WEBER 89

&&

.AVIATION...18Z TAFS...VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24
HOURS. THUNDERSTORMS ARE EXPECTED TO DEVELOP IN CENTRAL OREGON THIS
AFTERNOON...SO KRDM WILL HAVE A THREAT OF THUNDERSTORMS FROM 21Z
SUNDAY TO 06Z MONDAY. THESE THUNDERSTORMS WILL MOVE NORTHWARD INTO
NORTH CENTRAL OREGON AND SOUTH CENTRAL WASHINGTON BY LATE THIS
AFTERNOON AND CONTINUING THROUGH THIS EVENING. KDLS WILL HAVE A
THREAT OF THUNDERSTORMS FROM 00Z TO 06Z MONDAY.

&&

.FIRE WEATHER...RED FLAG WARNINGS AND FIRE WEATHER WATCHES HAVE BEEN
POSTED FOR THE LOWER ELEVATIONS OF THE FORECAST AREA THROUGH TUESDAY
MORNING...BASICALLY CONSIDERING AREAS WHERE THERE IS A LOT OF
GRASS, SHRUBS, AND SAGEBRUSH.  THE LARGER FUELS IN THE HIGHER
ELEVATIONS REMAIN MOIST ENOUGH THAT THE POTENTIAL FOR LARGE FIRE
GROWTH CAUSED BY LIGHTNING IS MINIMAL.  ALTHOUGH SOME STORMS WILL
PRODUCE MODERATE TO HEAVY RAIN TONIGHT AND MONDAY...THERE WILL BE
ABUNDANT LIGHTNING AS WELL.  ANOTHER FIRE WEATHER CONCERN IS THE
HIGH HAINES IN SE OREGON.  THE AIR MASS IS UNSTABLE AND DRY IN THIS
AREA.  THE HAINES WILL IMPROVE ON MONDAY AS MOISTURE INCREASES
ACROSS EASTERN OREGON.  JOHNSON

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  66 103  68  94 /  10  20  40  20
ALW  70 101  69  95 /  10  20  40  20
PSC  65 105  69  99 /  10  20  40  20
YKM  70 100  65  94 /  10  20  20  20
HRI  64 102  69  97 /  10  20  40  20
ELN  67 101  66  93 /  10  20  20  20
RDM  55  95  52  92 /  30  30  20  20
LGD  60  98  59  91 /  20  30  20  20
GCD  60  97  60  93 /  30  30  30  20
DLS  72  97  66  93 /  30  20  20  20

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 8 PM THIS EVENING TO 9 AM PDT TUESDAY FOR
     ORZ609-631.

     HEAT ADVISORY UNTIL 8 PM PDT MONDAY FOR ORZ041-044-501-505.

     FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY
     MORNING FOR ORZ638.

     RED FLAG WARNING UNTIL 9 AM PDT TUESDAY FOR ORZ610-630.

WA...RED FLAG WARNING FROM 8 PM THIS EVENING TO 9 AM PDT TUESDAY FOR
     WAZ609-631.

     HEAT ADVISORY UNTIL 8 PM PDT MONDAY FOR WAZ024-026>029-502.

     FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY
     MORNING FOR WAZ675.

&&

TI:YYG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
76/91/91

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
210 PM PDT SUN JUN 29 2008

UPDATED FIRE WEATHER WATCH AND RED FLAG WARNING INFORMATION

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-
210 PM PDT SUN JUN 29 2008

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

.DAY ONE...REST OF TODAY AND TONIGHT

EXCESSIVE HEAT
     EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON,
     EASTERN COLUMBIA RIVER GORGE, KITTITAS VALLEY, YAKIMA VALLEY,
     LOWER COLUMBIA BASIN, FOOTHILLS OF THE BLUE MOUNTAINS,
     NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES, JOHN DAY BASIN

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

RED FLAG WARNING
     EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN
     COLUMBIA RIVER GORGE OF WASHINGTON, LOWER COLUMBIA BASIN OF
     WASHINGTON, FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON,
     EASTERN COLUMBIA RIVER GORGE OF OREGON, NORTH CENTRAL OREGON,
     CENTRAL OREGON, LOWER COLUMBIA BASIN OF OREGON, FOOTHILLS OF
     THE BLUE MOUNTAINS OF OREGON, NORTHERN WHEELER AND SOUTHERN
     GILLIAM COUNTIES, OCHOCO-JOHN DAY HIGHLANDS

A RIDGE OF HIGH PRESSURE WILL CONTINUE TO BRING HOT AND DRY
CONDITIONS...AS THE REGION SEES THE THE HOTTEST TEMPERATURES SO FAR
THIS YEAR. MANY LOCATIONS WILL REACH OR EXCEED 100 DEGREES THIS
AFTERNOON.  PLEASE REFER TO PRODUCT PDXNPWPDT FOR DETAILS ON THE
HEAT ADVISORY.

A WEATHER DISTURBANCE ASSOCIATED WITH A LOW PRESSURE SYSTEM OFF THE
CALIFORNIA COAST WILL MOVE NORTHWARD INTO THE REGION THIS AFTERNOON.
THIS WILL PROVIDE ENOUGH INSTABILITY AND MOISTURE TO DEVELOP
THUNDERSTORMS IN CENTRAL OREGON AND SPREAD NORTHWARD ALONG THE
CASCADES AS WELL AS NORTHEAST OVER THE BLUE MOUNTAINS THIS EVENING.
WITH THE GRASSES AND SHRUBS IN THE LOWER ELEVATIONS BEING
DRY...SCATTERED THUNDERSTORMS FROM THIS AFTERNOON THROUGH TUESDAY
MORNING WILL THREATEN THESE AREAS WITH LIGHTNING-CAUSED FIRES. A RED
FLAG WARNING IS IN EFFECT THIS AFTERNOON THROUGH TUESDAY MORNING FOR
NORTH CENTRAL OREGON, CENTRAL OREGON, AND THE OCHOCO-JOHN DAY
HIGHLANDS. A RED FLAG WARNING IS IN EFFECT TONIGHT THROUGH TUESDAY
MORNING FOR THE SOUTH CENTRAL WASHINGTON.  PLEASE REFER TO FIRE
WEATHER PRODUCT PDXRFWPDT FOR MORE DETAILS. CONTACT YOUR LOCAL
FOREST OR LAND MANAGEMENT AGENCY FOR CURRENT FIRE DANGER CONDITIONS
IN YOUR AREA.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

STRONG THUNDERSTORMS MONDAY
     NORTHWEST BLUE MOUNTAINS, 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

EXCESSIVE HEAT MONDAY
     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, EASTERN COLUMBIA RIVER GORGE OF
     OREGON, LOWER COLUMBIA BASIN OF OREGON, FOOTHILLS OF THE BLUE
     MOUNTAINS OF OREGON

RED FLAG WARNING MONDAY
     EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN
     COLUMBIA RIVER GORGE OF WASHINGTON, LOWER COLUMBIA BASIN OF
     WASHINGTON, FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON,
     EASTERN COLUMBIA RIVER GORGE OF OREGON, NORTH CENTRAL OREGON,
     CENTRAL OREGON, LOWER COLUMBIA BASIN OF OREGON, FOOTHILLS OF
     THE BLUE MOUNTAINS OF OREGON, NORTHERN WHEELER AND SOUTHERN
     GILLIAM COUNTIES, OCHOCO-JOHN DAY HIGHLANDS

FIRE WEATHER WATCH MONDAY
     BAKER COUNTY, LOWER COLUMBIA BASIN OF WASHINGTON

THUNDERSTORMS TUESDAY THROUGH THURSDAY
     NORTHWEST BLUE MOUNTAINS, CENTRAL OREGON, LOWER COLUMBIA BASIN
     OF 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

THE RIDGE OF HIGH PRESSURE WILL KEEP CONDITIONS HOT AND DRY THROUGH
MONDAY. THE COLUMBIA BASIN AND SURROUNDING VALLEYS WILL CONTINUE TO
SEE HIGH TEMPERATURES EXCEEDING 100 DEGREES. PLEASE REFER TO
PDXNPWPDT FOR MORE DETAILS ON THE HEAT ADVISORY.

THE LOW PRESSURE SYSTEM OFF THE CALIFORNIA COAST WILL LIFT NORTHWARD
AND SEND ANOTHER...STRONGER DISTURBANCE ACROSS THE REGION MONDAY
AFTERNOON. WITH UNSTABLE CONDITIONS ACROSS THE AREA...THUNDERSTORMS
ARE POSSIBLE ACROSS THE REGION. A MARINE PUSH LATE ON MONDAY WILL
ADD FURTHER LIFT FOR STRONGER STORMS TO DEVELOP ACROSS THE MOUNTAINS
OF NORTHEAST OREGON AND SOUTHEAST WASHINGTON. THESE STORMS MAY BE
CAPABLE OF STRONG GUSTY WINDS AND LARGE HAIL. THERE IS ALSO A
POTENTIAL FOR LARGE FIRE GROWTH FOR THE AREAS COVERED UNDER FIRE
WEATHER WATCHES AND RED FLAG WARNINGS. SEE LATEST PDXRFWPDT FOR
DETAILS ON FIRE WEATHER WATCHES AND WARNINGS DUE TO LIGHTNING ON
MONDAY.

WEATHER DISTURBANCES WILL CONTINUE TO BRING UNSTABLE CONDITIONS TO
THE MOUNTAINS OF NORTHEAST OREGON AND SOUTHEAST WASHINGTON...WITH A
CHANCE OF THUNDERSTORMS EACH AFTERNOON THROUGH THE END OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE LIKELY OVER THE NEXT SEVERAL DAYS.

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.