Heavy Snow in Oregon, March 23 to 24, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
800 PM PST WED MAR 23 2005

.SHORT TERM...FORECAST ON TRACK.  THE ONLY UPDATE THIS EVENING WAS
TO REMOVE THUNDERSTORMS IN A FEW ZONES.  TWO LOWS ARE DUMBBELLING
AROUND ONE ANOTHER...ONE OVER SW BRITISH COLUMBIA AND ANOTHER ALONG
THE OREGON COAST.  THE TROUGH HAS OBTAINED A N-S ORIENTATION AND THE
FLOW HAS BACKED TO THE SOUTH ACROSS THE FORECAST AREA.  THE FORECAST
AREA IS SEEING A BREAK IN PRECIPITATION...AS INDICATED ON DOPPLER
RADAR AT PENDLETON.  YET THE LOW OVER THE OREGON COAST WILL SWING
TOWARDS THE CASCADE CREST THIS EVENING THEN OVER EASTERN OREGON
TONIGHT...BRINGING SCATTERED SHOWERS IN ITS PATH.  THE AIR MASS IS
UNSTABLE AND THE APPROACHING LOW WILL PROVIDE SOME LIFT...SO THERE
MAY BE A STRAY LIGHTNING STRIKE TONIGHT.  HOWEVER...THE LIGHTNING
STRIKES DETECTED OVER WESTERN OREGON DIMINISHED AFTER SUNSET SO
BELIEVE THE THREAT OF T-STORMS IN OUR FORECAST AREA IS SLIM TO NONE
DUE TO LACK OF DIURNAL HEATING.  SMITH

&&

.PREV DISCUSSION... (ISSUED 210 PM PST WED MAR 23 2005)

THE LOW ENDS UP OVER EASTERN OREGON ON THURSDAY SO HAVE INCLUDE AN
ISOLATED THUNDERSTORM THREAT THEN TOO. INCLUDED THE SOUTHERN
WASHINGTON CASCADES IN THE THUNDERSTORM THREAT EXPECTING SOME GOOD
HEATING TO HELP FIRE UP SOME CONVECTION TOMORROW AFTERNOON.
OTHERWISE LOOK FOR ISOLATED TO SCATTERED SHOWER ACTIVITY FOR NEXT 24
TO 36 HOURS AS UPPER LEVEL LOW MOVES OVER FORECAST AREA. LOW BEGINS
TO EXIT ON FRIDAY WITH WEAK RIDGING BUILDING IN FROM THE WEST. THIS
WILL PROCEED THE NEXT WEATHER SYSTEM EXPECTED TO ARRIVE SATURDAY AS
A WARM FRONT. MORE ON THIS IN THE EXTENDED PERIOD.

SATURDAY NIGHT THROUGH WEDNESDAY...POTENTIALLY ACTIVE WEATHER
PATTERN THROUGH THE EXTENDED PERIOD WITH THE POSSIBILITY OF SEVERAL
SYSTEMS IMPACTING THE PACIFIC NORTHWEST. GREATEST CONFIDENCE IN THE
FORECAST IS FOR THE END OF THE WEEKEND WHEN MODEL SOLUTIONS ARE
CLUSTERED TOGETHER. THE SYSTEM THAT WILL IMPACT THE REGION BEGINNING
SATURDAY WILL CONTINUE ITS EFFECTS SATURDAY NIGHT INTO SUNDAY WITH
COPIOUS MOISTURE AND THE POTENTIAL FOR SUBSTANTIAL RAINFALL. HAVE
BUMPED UP POPS FOR SATURDAY NIGHT TO JUST BELOW LIKELY AND
EVENTUALLY THEY MAY INDEED GO INTO THE LIKELY CATEGORY. ANOTHER
SYSTEM WILL MOVE THROUGH ON MONDAY KEEPING RAIN CHANCES IN THE
FORECAST. AFTER THAT...LATEST ECMWF/GFS DIFFER ON THE PATTERN OVER
THE PACIFIC NORTHWEST WITH THE MORE RIDGING EVIDENT IN THE ECMWF.
WITH THE MODEL DISCREPANCIES HAVE LEFT CURRENT FORECAST OF LOW
CHANCE POPS THROUGH WEDNESDAY GOING FOR NOW. TEMPERATURES THROUGHOUT
THE PERIOD WILL BE SEASONABLE AS WILL SNOW LEVELS.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  33  44  32  49 /  20  30  30  20
ALW  33  47  32  50 /  20  30  30  20
PSC  31  53  29  55 /  10  20  20  20
YKM  30  51  30  53 /  10  20  20  20
HRI  31  51  29  53 /  10  20  20  20
ELN  27  51  26  51 /  10  20  20  20
RDM  29  40  25  45 /  50  30  30  20
LGD  32  42  29  46 /  40  40  40  20
5J0  31  37  29  40 /  50  40  40  20
DLS  34  51  32  54 /  30  20  20  20

&&

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

&&

TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
85/

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
842 AM PST WED MAR 23 2005

ORZ041>050-WAZ024>030-241300-
NORTH CENTRAL OREGON-CENTRAL OREGON-LOWER COLUMBIA BASIN (OR)-
FOOTHILLS OF THE BLUE MOUNTAINS (OR)-BLUE MOUNTAINS-
JOHN DAY BASIN-OCHOCO-JOHN DAY HIGHLANDS-GRANDE RONDE VALLEY-
WALLOWA COUNTY-EAST COLUMBIA RIVER GORGE (WA)-
EAST SLOPES OF THE SOUTHERN CASCADES-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN (WA)-
FOOTHILLS OF THE BLUE MOUNTAINS (WA)-NORTHWEST BLUE MOUNTAINS-
842 AM PST WED MAR 23 2005

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

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

SCATTERED RAIN AND SNOW SHOWERS WILL CONTINUE ACROSS THE FORECAST
AREA TODAY...WITH LITTLE OR NO ADDITIONAL ACCUMULATION EXPECTED.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

THE UPPER LEVEL LOW WILL MOVE EAST OVER OREGON THURSDAY AND THURSDAY
NIGHT. THIS WILL KEEP PRECIPITATION OVER EASTERN OREGON AND
SOUTHEAST WASHINGTON. PRECIPITATION WILL TAPER OFF FRIDAY AS A RIDGE
BUILDS OVER THE PACIFIC NORTHWEST. A SERIES OF DISTURBANCES WILL
MOVE INTO THE PACIFIC NORTHWEST SATURDAY THROUGH TUESDAY KEEPING A
CHANCE OF PRECIPITATION OVER THE AREA. SNOW LEVELS WILL BE HIGHER
WITH THESE SYSTEMS...WITH SNOWFALL CONFINED TO THE MOUNTAINS.

.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.

PROTOTYPE GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:

WWW.WRH.NOAA.GOV/PENDLETON/CURRENTHAZARDS/GRAPHICALHAZARDS.PHP?TAB=1

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
359 PM PST WED MAR 23 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     HEAVY SNOW       N LA PINE               43.67N 121.50W
03/23/2005  5.5 INCH         DESCHUTES          OR   TRAINED SPOTTER

            3 INCHES SNOW DURING PREVIOUS EVENING...THEN 2.5 INCHES
            OVERNIGHT FOR A TOTAL OF 5.5 INCHES.

&&

RCLOUT