Hail in Oregon, July 29, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
322 PM PDT THU JUL 29 2010

UPDATED AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...LOCAL LAPS SURFACE
ANALYSIS SHOWS CAPE INCREASING OVER HIGHER TERRAIN THIS AFTERNOON.
CUMULUS CLOUDS ARE DEVELOPING AND RUC MODEL SHOWS ISOLATED
CONVECTIVE PRECIPITATION DEVELOPING THIS EVENING.  AS
SUCH...ISOLATED THUNDERSTORMS ARE EXPECTED OVER HIGHER TERRAIN THIS
EVENING.  PRECIPITABLE WATER VALUES ARE ABOVE NORMAL...AROUND ONE
INCH...BUT THE BOUNDARY LAYER IS DRY.  AS SUCH...BOTH LOCALLY HEAVY
RAIN AND GUSTY WINDS ARE POSSIBLE WITH ANY THUNDERSTORMS.  THE
SURFACE AIR MASS WILL STABILIZE QUICKLY AFTER SUNSET BUT ELEVATED
INSTABILITY COULD BE RELEASED BY A WEAK IMPULSE ALOFT OVERNIGHT.  AS
SUCH...THERE IS A SLIGHT CHANCE FOR SHOWERS OR THUNDERSTORMS
OVERNIGHT FROM DESCHUTES AND JEFFERSON COUNTIES EASTWARD TO WALLOWA
COUNTY.

FRIDAY...SOUTHWEST FLOW ALOFT INCREASES AS A LOW-PRESSURE TROUGH
MOVES EASTWARD INTO THE PACIFIC NORTHWEST.  THE AIR MASS WILL
DESTABILIZE FOR ISOLATED TO POSSIBLY SCATTERED THUNDERSTORMS AND AS
SUCH A RED FLAG WATCH HAS BEEN ISSUED FOR POTENTIALLY DANGEROUS FIRE
GROWTH CONDITIONS...SEE PRODUCT PDXRFWPDT FOR DETAILS. A JET OF
MAXIMUM STRONG WIND ALOFT IS EXPECTED TO MOVE ACROSS CENTRAL OREGON
IN THE AFTERNOON AND THEN ACROSS NORTHEAST OREGON AND SOUTHEAST
WASHINGTON IN THE EVENING.  THE TIMING OF THIS JET MAX MAY PROVIDE
THE BEST THREAT FOR STRONG TO SEVERE STORMS FRIDAY AFTERNOON AND
EVENING.  INSTABILITY WILL BE SOMEWHAT MARGINAL BUT THERE COULD BE
POCKETS WITH ENOUGH INSTABILITY FOR ORGANIZED STORMS.
FURTHERMORE...IT APPEARS THE STRONGEST FORCING FOR LIFT WILL ARRIVE
EAST OF THE CASCADES LATE IN THE EVENING AFTER PEAK HEATING.  THE
SLOWER TIMING OF THIS STRONG FORCING SHOULD BE A LIMITING FACTOR IN
THE COVERAGE OF STRONG STORMS.  BOTTOM LINE...THESE FACTORS ARE NOT
EXPECTED TO ARRIVE TOGETHER TO SUPPORT MORE THAN ISOLATED SEVERE
STORMS...BUT A FEW SEVERE STORMS WITH LARGE HAIL...HEAVY RAIN...AND
STRONG WINDS ARE POSSIBLE FRIDAY AFTERNOON AND EVENING.

FRIDAY NIGHT THROUGH SUNDAY...FRIDAY NIGHT THERE IT APPEARS THERE
WILL AGAIN BE A SLIGHT RISK FOR SHOWERS AND THUNDERSTORMS OVERNIGHT
ACROSS THE NORTHEAST PORTION OF THE FORECAST AREA.  SATURDAY THE
LOW-PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE FORECAST
AREA...MOVING INTO NORTHERN WASHINGTON BY PEAK HEATING TIME SATURDAY
AFTERNOON.  THE TIMING IS UNCERTAIN...BUT AT THIS TIME IT APPEARS
THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MAINLY BE DURING
EARLY AFTERNOON SATURDAY IN THE PENDLETON FORECAST AREA.  SATURDAY
THERE MAY BE BREEZY TO WINDY WEST WINDS AND SATURDAY NIGHT AND
SUNDAY SHOULD BE DRY.  80

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...MODELS AGREE WITH THE
GENERAL PATTERN OF A TROUGH OF LOW PRESSURE OVER THE PACIFIC
NORTHWEST NEXT WEEK. HOWEVER...THEY CONTINUE TO DISAGREE ON THE
PLACEMENT AND STRENGTH OF THE LOW PRESSURE CENTER. THE TREND HAS
BEEN FOR THE LOW TO DROP SOUTH OUT OF CANADA AND SPIN OFF THE COAST
OF WASHINGTON. THE GFS MODEL NEWER RUNS ARE STRONGER WITH THE LOW AS
WELL AS FURTHER ONSHORE IN WESTERN WASHINGTON. THE NEWER EUROPEAN
RUNS ARE WEAKER AND KEEPING THE LOW IN SOUTHERN CANADA. THE LOCATION
OF THIS LOW WILL IMPACT TEMPERATURES ACROSS THE REGION THE MOST...IN
THAT FURTHER ONSHORE WILL MEAN COOLER TEMPERATURES THAN IF THE LOW
SETS UP OFF SHORE. PRECIPITATION SEEMS TO REMAIN NORTH OF THE
FORECAST AREA IN ALL OF THE MODELS...THOUGH DISTURBANCES IN THE FLOW
MAY TRIGGER THUNDERSTORM DEVELOPMENT IN THE MOUNTAINS. HAVE KEPT THE
FORECAST DRY UNTIL MID WEEK AS THE CURRENT GFS MODEL AS WELL AS PAST
RUNS OF THE EUROPEAN SHOW THE LOW MOVING EASTWARD ACROSS THE AREA.
FORECAST CONFIDENCE IS LOW DUE TO MODEL UNCERTAINTIES IN THE LATER
EXTENDED. DMH

&&

.AVIATION...00Z TAFS...VFR CONDITIONS WILL PREDOMINATE FOR THE NEXT
24 HOURS. CUMULUS WILL CONTINUE TO BUILD THIS EVENING...ESPECIALLY
OVER THE HIGHER TERRAIN. AN ISOLATED THUNDERSTORM IS POSSIBLE THOUGH
WILL ONLY KEEP CB MENTION IN KRDM...KPDT AND KALW AS THESE LOCATIONS
HAVE THE BETTER CHANCE OF A THUNDERSTORM DEVELOPING IN THE VICINITY.
THE BETTER CHANCES FOR THUNDERSTORM DEVELOPMENT WILL BE TOMORROW FOR
CENTRAL AND NORTHEAST OREGON AS WELL AS CENTRAL WASHINGTON CASCADES.
WILL INDICATE CB FOR NOW IN THE TAFS LIKELY TO BE IMPACTED. SURFACE
WINDS WILL BE 10 TO 15 KTS FOR KDLS THIS EVENING AND IS EXPECTED TO
DECREASE OVERNIGHT. DMH

&&

.FIRE WEATHER...ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS EXPECTED
ON FRIDAY ACROSS CENTRAL AND NE OREGON.  THE STRENGTH OF THE MID
LEVEL SHEAR WILL RESULT IN STRONG UPDRAFTS AND DEEP VERTICAL
DEVELOPMENT WITH MANY OF THE STORMS...THUS THERE IS A POTENTIAL FOR
NUMEROUS STRIKES.  WILL BE ISSUING A FIRE WEATHER WATCH FOR OUR
CENTRAL AND NE OREGON ZONES FOR FRI AFTN THRU FRI EVE.  HEAVY RAIN
MAY BE ASSOCIATED WITH SOME STORMS...BUT MANY WILL BE HIGH BASED
WITH THE POSSIBILITY OF STRONG OUTFLOWS. ANOTHER FIRE WEATHER
CONCERN IS THE WINDS AND RH'S IN THE COLUMBIA BASIN AND EASTERN
COLUMBIA RIVER GORGE.  SURFACE GRADIENTS TIGHTEN ON FRIDAY JUST EAST
OF THE CASCADE RANGE TO INDICATE INCREASING WINDS...BUT THE MARINE
LAYER WILL NOT BE DEEP ENOUGH TO FORCE COOLER AIR THROUGH THE
CASCADE GAPS.  THE EASTERN COLUMBIA GORGE...HOWEVER... WILL HAVE
INCREASING WINDS FRIDAY AFTERNOON. I EXPECT 10-20 MPH WINDS TO MAKE
IT AS FAR EAST AS BOARDMAN ALONG THE I-84 CORRIDOR...AND POSSIBLY AS
FAR EAST AS PENDLETON BY LATE AFTERNOON.  CONFIDENCE IS ABOUT 50/50
ON WHETHER WINDS AND RH'S COMBINED WILL MEET RED FLAG CRITERIA.  FOR
NOW...WILL HIGHLIGHT IN THE FORECAST AND NOT ISSUE A WATCH AT THIS
TIME.

ON SATURDAY...WINDS WILL INCREASE OVER THE REMAINDER OF THE COLUMBIA
BASIN WITH GENERAL WINDS RANGING FROM 10-25 MPH.  IT DOES NOT APPEAR
TO BE A WIND EVENT BUT IT IS BORDERLINE RED FLAG CONDITIONS AS RH'S
WILL BE AROUND THE 18-30 PERCENT RANGE SATURDAY AFTERNOON.  THERE IS
A SLIGHT CHANCE TO A CHANCE OF THUNDERSTORMS ON SATURDAY BUT WILL
ADDRESS THE NEED FOR FUTURE STATEMENTS TOMORROW...AS MOST OF THE
ACTIVITY WILL BE NORTH OF THE FORECAST AREA.  JOHNSON

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  59  92  59  86 /  10  20  20  20
ALW  60  94  62  88 /  10  20  20  20
PSC  61  95  62  91 /  10  10  20  20
YKM  56  92  56  87 /  10  10  20  20
HRI  59  95  60  88 /  10  10  20  20
ELN  55  93  55  85 /  10  10  20  20
RDM  46  87  46  83 /  20  20  20  10
LGD  56  89  55  83 /  20  30  30  20
GCD  56  90  55  84 /  20  20  20  20
DLS  55  87  55  80 /  10  10  10  10

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
     ORZ042-043-049-501>506.

WA...FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
     WAZ030.

&&

THREAT INDEX
FRIDAY : GREEN
SATURDAY : YELLOW
SUNDAY : 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

80/84/84/85

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
325 PM PDT THU JUL 29 2010

UPDATED FIRE WEATHER WATCH 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 OF WASHINGTON-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
325 PM PDT THU JUL 29 2010

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

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 OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF OREGON, NORTH CENTRAL OREGON, CENTRAL 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

ISOLATED THUNDERSTORMS WILL DEVELOP LATE THIS AFTERNOON AND
EVENING.  BRIEF HEAVY RAIN...GUSTY WINDS...AND SMALL HAIL CAN BE
EXPECTED WITH MOST THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

FIRE WEATHER WATCH FRIDAY
     FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON, NORTHWEST BLUE
     MOUNTAINS OF WASHINGTON, NORTH CENTRAL OREGON, CENTRAL 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

     CONTACT YOUR LOCAL FOREST OR LAND MANAGEMENT AGENCY FOR
     CURRENT FIRE DANGER CONDITIONS IN YOUR AREA.

THUNDERSTORMS FRIDAY
     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, EAST SLOPES
     OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF WASHINGTON, EASTERN COLUMBIA RIVER GORGE OF OREGON,
     NORTH CENTRAL OREGON, GRANDE RONDE VALLEY, WALLOWA COUNTY

ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS EXPECTED ON FRIDAY
ACROSS CENTRAL AND NE OREGON.  THE STRENGTH OF THE APPROACHING
SYSTEM WILL RESULT IN STRONG UPDRAFTS AND DEEP VERTICAL DEVELOPMENT
WITH MANY OF THE STORMS...THUS THERE IS A POTENTIAL FOR NUMEROUS
LIGHTNING STRIKES.  THE COMBINATION OF ABUNDANT LIGHTNING AND DRY
FUELS MAY POSSIBLY RESULT IN RED FLAG CONDITIONS...AND A FIRE
WEATHER WATCH HAS BEEN ISSUED FOR THE AREAS LISTED ABOVE.  FOR
DETAILS...REFER TO THE NWS PRODUCT PDXRFWPDT.

ON SATURDAY THUNDERSTORMS WILL PRIMARILY THREATEN ONLY THE BLUE
MOUNTAINS...GRANDE RONDE VALLEY AND WALLOWA COUNTY AS WELL AS THE
SOUTHEAST WASHINGTON BLUE MOUNTAINS. SOME THUNDERSTORMS MAY ALSO
OCCUR OVER THE SOUTHERN AND CENTRAL WASHINGTON CASCADE EAST SLOPES
ON SATURDAY. ELSEWHERE WILL CONTINUE TO BE VERY WARM TO HOT THROUGH
THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK WITH DRY CONDITIONS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THROUGH LATE FRIDAY.

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.