Flash Flood in Oregon, April 26, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
905 AM PDT TUE APR 26 2005

.UPDATE...HAVE DECIDED TO UPDATE FORECAST TO INCLUDE TSRA OVER THE
FAR EASTERN REGION OF THE FORECAST AREA THAT INCLUDES WALLOWA AND
BLUE MOUNTAINS. EVEN GOING WITH THE MORE CONSERVATIVE NAM THE 7/5H
LAPSE RATES ARE BETTER THAN 7C.KM AND WITH DAYTIME HEATING HIGH
K INDICES/TTOTALS ETC FEEL CONVECTION WILL DEVELOP THIS AFTERNOON.
DESPITE WEAK FLOW ALOFT STILL FEEL WITH STRONG VERTICAL VELOCITIES
WE COULD GET SOME HAIL NEARING PENNY SIZE. OTHERWISE...HAVE
INCREASED AFTN HIGH TEMPS ACROSS THE LOWER COLUMBIA BASIN A COUPLE
OF DEGREES.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  76  53  65  39 /   5   0  10   0
ALW  78  54  67  40 /   5   0  10   0
PSC  82  51  68  38 /   0   0  10   0
YKM  82  50  68  35 /   0   0  10   0
HRI  81  51  69  37 /   0   0  10   0
ELN  81  48  65  33 /   5   0  10   0
RDM  74  44  68  36 /  20  20  20  20
LGD  73  47  63  37 /  10  10  20  20
5J0  73  44  68  37 /  20  20  20  20
DLS  77  53  69  40 /   0   0  10   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
920 AM PDT TUE APR 26 2005

WAZ024>030-ORZ041>050-271215-
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-
920 AM PDT TUE APR 26 2005

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

.DAY ONE...

THUNDERSTORMS
     NORTHWEST BLUE MOUNTAINS, NORTH CENTRAL OREGON, CENTRAL
     OREGON, BLUE MOUNTAINS, JOHN DAY BASIN, OCHOCO-JOHN DAY
     HIGHLANDS, GRANDE RONDE VALLEY, WALLOWA COUNTY

AN UPPER LEVEL LOW OFF THE COAST OF CALIFORNIA WILL SPREAD SOME
MOISTURE AND INSTABILITY OVER CENTRAL OREGON TODAY. THIS WILL
RESULT IN A SLIGHT CHANCE OF SOME LATE DAY THUNDERSTORMS FROM THE
JOHN DAY REGION WEST TO THE CASCADES MOUNTAINS.

IN ADDITION...WITH DAYTIME HEATING...LOW LEVEL MOISTURE...AND BETTER
INSTABILITY SPECIFICALLY NEAR WALLOWA...THUNDERSTORMS ARE EXPECTED
TO DEVELOP THIS AFTERNOON AND SOME STORMS MAY BECOME STRONG WITH
HAIL NEARING PENNY SIZE.

WHILE STRONG STORMS ARE POSSIBLE ACROSS ANY LOCATION...THE
GREATEST CHANCES WILL BE EAST OF A LINE FROM DAYTON WASHINGTON TO
JOHN DAY OREGON.

.DAYS TWO THROUGH SEVEN...

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED MAINLY EAST OF A LINE FROM DAYTON
WASHINGTON TO JOHN DAY OREGON THIS AFTERNOON AND EVENING.

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:

WWW.WRH.NOAA.GOV/PENDLETON/CURRENTHAZARDS/HWO.HTML

ALL LETTERS IN THE ABOVE URL ARE LOWER CASE...EXCEPT THE H IN
CURRENT HAZARDS.