Debris Flow in Washington, October 10 to 11, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
315 PM PDT SAT OCT 10 2009

UPDATED AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT. THE STATIONARY FRONT
OVER SOUTH CENTRAL WASHINGTON AND NE OREGON IS GRADUALLY SAGGING
SOUTHWARD.  THE UPPER FLOW IS STARTING TO BUCKLE WHICH IS CAUSING
THE FRONT TO STRETCH AND THE BAND OF CLOUDS TO THIN OUT SOME.
CONFIDENCE HAS INCREASED THAT WIDESPREAD FREEZING TEMPERATURES WILL
BE OBSERVED TONIGHT ACROSS THE COLUMBIA BASIN AND SURROUNDING
VALLEYS.  CURRENT DEWPOINTS ARE IN THE TEENS (SINGLE DIGITS IN THE
NORTHEAST MOUNTAINS)...SO CLEARING SKIES TONIGHT WILL CAUSE
TEMPERATURES TO PLUMMET.  BY SUNDAY...SKIES WILL BE MOSTLY SUNNY
WITH INCREASING HIGH CLOUDS IN THE LATE AFTERNOON. AFTERNOON
TEMPERATURES ON SUNDAY WILL BE IN THE 40S TO AROUND 50 OVER MOST OF
THE AREA.  FORECAST DEWPOINTS WILL BE IN THE TEENS IN THE BASIN AND
-5F TO 10F IN THE MOUNTAINS.  RECORD BREAKING LOWS SUNDAY NIGHT ARE
LIKELY.

A COMPLEX PATTERN BEGINS TO DEVELOP ON MONDAY AND MONDAY NIGHT.  A
LOW WILL DEEPEN OFF THE EASTERN PACIFIC ALONG 40N AND WILL TRACK
EAST TOWARDS THE CALIFORNIA COAST.  THIS WILL INCREASE THE SOUTHERLY
FLOW ACROSS OREGON MONDAY NIGHT...AND ACROSS WASHINGTON ON TUESDAY.
INCREASING CLOUDS AND WARM AIR ADVECTION ALOFT WILL TAKE PLACE OVER
THE FORECAST AREA MONDAY NIGHT WITH INCREASING TEMPERATURES AND SNOW
LEVELS THROUGH THE NIGHT. STRATIFORM PRECIPITATION WILL BEGIN TO
SPREAD OVER THE CASCADES (MAINLY OREGON) EARLY TUESDAY MORNING.
SNOW LEVELS WILL INCREASE TO AROUND 5000 FEET IN CENTRAL OREGON
TUESDAY MORNING.

.LONG TERM...TUESDAY THROUGH SATURDAY...A LOW PRESSURE SYSTEM OFF
THE PACIFIC COAST WILL SEND A WARM FRONT THROUGH THE REGION ON
TUESDAY. WITH RISING SNOW LEVELS DURING THE DAY...PRECIPITATION WILL
FALL MOSTLY AS RAIN ACROSS THE REGION. ANOTHER DISTURBANCE SWINGING
AROUND THE BOTTOM OF THE TROUGH WILL KEEP PRECIPITATION GOING
TUESDAY NIGHT INTO WEDNESDAY. A RIDGE TRIES TO DEVELOP OVER THE
PACIFIC NORTHWEST WEDNESDAY NIGHT AND THURSDAY...BUT DISTURBANCES
CONTINUE TO MOVE THROUGH THE FLOW AIDED BY A JET LIFTING NORTH OVER
THE AREA. WILL KEEP AT LEAST A SLIGHT CHANCE OF PRECIPITATION
THROUGH THE EXTENDED AS THE TIMING OF EACH DISTURBANCE VARIES
BETWEEN MODELS. ONE DISTURBANCE MAY MOVE THROUGH ON THURSDAY AND
ANOTHER ON FRIDAY FOR AN INCREASED THREAT OF SHOWERS. DMH

&&

.AVIATION...00Z TAFS...VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24
HOURS. A FRONTAL BAND IS CURRENTLY ACROSS CENTRAL WASHINGTON AND
EASTERN OREGON AND IS SLOWLY MOVING SOUTHWARD. MID LEVEL CLOUDS ARE
ASSOCIATED WITH THIS SYSTEM AND ARE GRADUALLY DECREASING AS A WAVE
STRETCHES THE FRONT. DMH

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  24  47  22  50 /   0   0   0   0
ALW  24  48  23  52 /   0   0   0   0
PSC  24  51  22  53 /   0   0   0   0
YKM  22  49  20  51 /   0   0   0   0
HRI  25  51  23  53 /   0   0   0   0
ELN  22  48  20  48 /   0   0   0   0
RDM  23  50  21  53 /   0   0   0  10
LGD  20  46  19  53 /   0   0   0   0
GCD  24  48  20  55 /   0   0   0   0
DLS  29  52  27  54 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HARD FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM PDT SUNDAY
     FOR ORZ044-501.

     FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM PDT SUNDAY FOR
     ORZ041.

WA...HARD FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM PDT SUNDAY
     FOR WAZ026-028-029.

     FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM PDT SUNDAY FOR
     WAZ024.

&&

THREAT INDEX
SUNDAY : GREEN
MONDAY : GREEN
TUESDAY : 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

85/84/84

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
225 PM PDT SAT OCT 10 2009

UPDATED TO REMOVE FREEZE WARNING INFORMATION THIS MORNING

ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-111145-
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-
225 PM PDT SAT OCT 10 2009

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

.DAY ONE...TODAY AND TONIGHT

FREEZE WARNING
     EASTERN COLUMBIA RIVER GORGE OF WASHINGTON, KITTITAS 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

A COLD FRONT IS SLOWLY MOVE SOUTHWARD ACROSS THE REGION AND WILL BE
LOCATED OVER CENTRAL OREGON THIS EVENING. SKIES WILL BECOME MOSTLY
CLEAR BEHIND THE FRONT TONIGHT AND SUNDAY MORNING ALLOWING FOR
RAPIDLY FALLING TEMPERATURES. THIS WILL RESULT IN A HARD FREEZE IN
MOST AREAS. A FREEZE OR HARD FREEZE WARNING IS IN EFFECT TONIGHT AND
SUNDAY MORNING FOR ALL AREAS LISTED ABOVE...WHICH HAVE YET TO
EXPERIENCE A WIDESPREAD FREEZE. PLEASE REFER TO NWS PRODUCT ID
PDXNPWPDT FOR MORE DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

A DRY NORTHERLY FLOW WILL CONTINUE SUNDAY THROUGH MONDAY MORNING
WITH MUCH COOLER THAN NORMAL TEMPERATURES. BY LATE MONDAY INTO
TUESDAY THE FLOW ALOFT WILL BECOME MORE WESTERLY AND THEN
SOUTHWESTERLY AS A WEATHER SYSTEM MOVES INTO THE REGION. THIS WILL
RESULT IN WARMER TEMPERATURES ALONG WITH MOIST SHOWERY CONDITIONS
WHICH ARE EXPECTED PERSIST THROUGH MOST OF NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

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.