Heavy Snow in Oregon, February 16 to 17, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
255 PM PST THU FEB 16 2006

.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...COLD AIR HAS BEGUN
FILTERING IN TO THE REGION AS AN ARCTIC COLD FRONT IS MOVING THROUGH
THE REGION AND IS ROUGHLY ALONG THE BASE OF THE BLUE MOUNTAINS AT
THIS TIME. THE REAL PUSH OF COLD AIR SHOULD START TAKING PLACE THIS
EVENING AS PRESSURE GRADIENTS TIGHTEN UP BETWEEN HIGH PRESSURE
ASSOCIATED WITH THE COLDER AIR AND LOWER PRESSURE OFF OUR COAST.
THIS WILL KICK UP BREEZY NORTH TO NORTHEAST WINDS TO CARRY THE
COLDER AIR INTO THE AREA. THE ARCTIC AIR IS QUITE DRY BUT AS THE AIR
BEGINS TO ENCOUNTER UPLIFT ALONG THE BLUE MOUNTAIN FOOTHILLS..THE
BLUE MOUNTAINS THEMSELVES...THE MOUNTAINS OF CENTRAL AND NORTHEAST
OREGON AND THE DESCHUTES PLATEAU...INTERACTION WITH MOISTURE ALREADY
IN PLACE SHOULD ALLOW SNOW SHOWERS TO OCCUR TONIGHT AND TOMORROW
MORNING...ALTHOUGH AMOUNTS SHOULD BE FAIRLY LIGHT. THE MOST FAVORED
AREAS WILL BE IN WALLOWA COUNTY WHERE THE NORTHEAST WINDS ARE BEST
FOR DECENT SNOWFALL AND IN CENTRAL OREGON...BUT AMOUNTS WILL BE 2 TO
3 INCHES OR LESS. MUCH OF THE REST OF THE AREA MAY SEE SNOW
FLURRIES. LOW TEMPERATURES WILL DROP TO 10 TO 15 IN THE COLUMBIA
BASIN AND AS LOW AS 5 BELOW ZERO IN THE COLDEST MOUNTAIN LOCATIONS.
RECORD LOW TEMPERATURES ARE POSSIBLE IN A NUMBER OF LOCATIONS. IN
ADDITION...BREEZY WINDS BEHIND THE FRONT WILL CREATE VERY LOW WIND
CHILLS...ESPECIALLY IN THE MOUNTAINS...BUT WILL NOT QUITE REACH
WIND CHILL ADVISORY CRITERIA. FRIDAY WILL SEE AN END TO THE
PRECIPITATION EXCEPT IN THE VERY SOUTHERN PORTIONS OF THE AREA.
TEMPERATURES WILL FALL INTO THE 20S IN LOWER LYING AREAS AND IN THE
TEENS IN THE MOUNTAINS. FRIDAY NIGHT WILL BE ANOTHER COLD ONE AS
TEMPERATURES DROP ANOTHER 2 TO 3 DEGREES FROM THURSDAY NIGHT. ONCE
AGAIN RECORD LOW TEMPERATURES WILL BE WIDESPREAD...MORE SO THAN
TONIGHT. WINDS WILL BE FAIRLY LIGHT SO WIND CHILLS WILL BE LESS OF A
PROBLEM. SATURDAY WILL BE DRY AND SHOULD SEE A WARM UP BEGIN AS THE
AIR MASS MODERATES AND TEMPERATURES REBOUND 5 OR SO DEGREES. THE DRY
AND WARMING TREND WILL CONTINUE INTO SATURDAY NIGHT. 83

.LONG TERM...SUNDAY THROUGH THURSDAY...THE REMNANTS OF THE COLD
UPPER LOW OVER THE GREAT BASIN LOOKS TO FILL AND SHIFT EAST SUNDAY.
AS A RESULT MOISTURE DECREASES AND CHANCES OF PRECIPITATION WILL BE
LIMITED TO A FEW HIGH MOUNTAIN PEAKS IN CENTRAL OREGON SUNDAY AND
SUNDAY NIGHT. UPPER FLOW BECOMES WEST-NORTHWEST TO NORTHWEST
STARTING MONDAY...AND THIS PATTERN LOOKS TO HOLD THROUGH THURSDAY.
THIS WOULD RESULT IN MODERATING TEMPERATURES...THOUGH THEY PROBABLY
WILL STILL BE A BIT BELOW SEASONAL. ALSO COULD SEE SOME FAST MOVING
SYSTEMS CROSS THE REGION. THESE SYSTEMS WOULD MOST LIKELY AFFECT THE
MOUNTAINS AND OTHER FAVORED UPSLOPE AREAS...WHILE FAVORED DOWN SLOPE
AREAS WOULD STAY MOSTLY DRY. THUS HAVE FORECAST THAT INDICATES
SLIGHT CHANCE TO LOW CHANCE POPS OVER MOST OF THE MOUNTAINS...WITH
DRY CONDITIONS ELSEWHERE...MONDAY THROUGH THURSDAY. 90

&&

.AVIATION...AT KYKM...KPSC...KALW...KPDT AND KDLS...A COLD FRONT
CONTINUES TO MOVE THROUGH NORTHERN OREGON THIS AFTERNOON. STILL
EXPECT CEILINGS TO GENERALLY RUN BETWEEN 4500 AND 9000 FEET AGL
THROUGH THIS EVENING WITH SKIES SCATTERING AT MOST OF THESE SITES
AFTER MIDNIGHT. UPSLOPE MAY KEEP LOW VFR CONDITIONS GOING AT KPDT
THROUGH FRIDAY MORNING. PRECIP WILL BE LIMITED TO A FEW FLURRIES OR
ISOLATED SNOW SHOWERS DUE TO POST FRONTAL UPSLOPE AFFECTS THIS
EVENING. VISIBILITIES COULD BRIEFLY (FOR 1 HOUR OR LESS) GO TO MVFR
IF A HEAVIER SNOW SHOWER MOVES OVER ONE OF THESES SITES.

AT KRDM...EXPECT VFR CONDITIONS INTO EARLY EVENING...THEN THE COLD
FRONT WILL MOVE THROUGH THIS LOCATION. LOW END VFR WITH SOME
FLURRIES OR ISOLATED SNOW SHOWERS WILL ACCOMPANY THE FRONT. THERE
COULD BE A PERIOD OF MVFR CEILINGS AND AN INCREASED CHANCE OF A SNOW
SHOWER FROM AROUND MIDNIGHT THROUGH THE EARLY MORNING HOURS DUE TO
UPSLOPE AFFECTS. 90

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  12  23  10  28 /  30  10   0   0
ALW  12  25  12  29 /  30  10  10  10
PSC  11  27   8  32 /  10  10   0   0
YKM  13  27   7  33 /  20  10   0   0
HRI  11  26   8  31 /  10  10  10  10
ELN   8  26   5  32 /  20  10   0   0
RDM   5  19   0  26 /  30  30  20  20
LGD  11  20   7  25 /  50  20  10  10
5J0   9  22   5  28 /  20  20  10  10
DLS  14  30  11  35 /  20  10  10  10

&&

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

TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
83/90/90

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
500 AM PST THU FEB 16 2006

WAZ024-501-502-026>030-ORZ041>044-049-050-501>506-171500-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
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-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-
500 AM PST THU FEB 16 2006

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

.DAY ONE...TODAY AND TONIGHT

EXTREME COLD
     EASTERN COLUMBIA RIVER GORGE OF WASHINGTON, EAST SLOPES OF THE
     CENTRAL CASCADES OF WASHINGTON, EAST SLOPES OF THE SOUTHERN
     CASCADES OF WASHINGTON, 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, 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

AN ARCTIC FRONT WILL CROSS THE AREA TODAY AND TONIGHT...BRINGING
VERY COLD AIR TO THE REGION. OVERNIGHT LOWS TONIGHT WILL BE BELOW
ZERO IN THE MOUNTAINS AND IN THE SINGLE DIGITS TO LOW TEENS AT THE
LOWER ELEVATIONS. ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED
WITH THE FRONT THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

EXTREME COLD FRIDAY AND SATURDAY
 	EASTERN COLUMBIA RIVER GORGE OF WASHINGTON, EAST SLOPES OF THE
	CENTRAL CASCADES OF WASHINGTON, EAST SLOPES OF THE SOUTHERN
	CASCADES OF WASHINGTON, 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, 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

COLD AIR WILL PREVAIL THROUGH THE WEEKEND...WITH LOWS BELOW ZERO
IN THE MOUNTAINS AND IN THE SINGLE DIGITS TO LOW TEENS AT THE
LOWER ELEVATIONS. HIGH TEMPERATURES WILL REMAIN BELOW FREEZING ACROSS
MOST LOCATIONS. THE COLD AIR WILL LINGER INTO EARLY NEXT WEEK BEFORE
A SLOW WARMUP BEGINS.

.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/PENDLETON/CURRENTHAZARDS/HWO.HTML

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