Area Forecast Discussion
Issued by NWS Pendleton, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KPDT 271748
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
948 AM PST FRI FEB 27 2015

.SHORT TERM...MORNING UPDATE...A PACIFIC SYSTEM WILL SLIDE
SOUTH-SOUTHEAST ALONG THE PACIFIC NORTHWEST COAST TODAY. THE MAIN
DEFORMATION PRECIP BAND WITH THIS SYSTEM CURRENTLY RUNS FROM HARNEY
COUNTY IN SOUTHEAST OREGON NORTH-NORTHWEST TO CENTRAL WASHINGTON.
THIS BAND WILL GRADUALLY PIVOT THROUGH THE DAY, ALIGNING ITSELF FROM
MALHEUR COUNTY IN SOUTHEAST OREGON TO SOUTH-CENTRAL WASHINGTON BY
LATE AFTERNOON. NORTH AND EAST OF THIS BAND PRECIP WILL BE LIMITED
AND LIGHT, MEANWHILE WILL SEE SHOWERS WEST OF THE BAND. THUS HAVE
CHANGED WEATHER WORDING TO SHOWERS FOR MOST OF NORTH-CENTRAL AND
CENTRAL OREGON FOR TODAY. ALSO MAY SEE ENOUGH INSTABILITY FOR A
STRAY THUNDERSTORM OVER THE SOUTHERN THREE-FOURTHS OF THE OREGON
CASCADE EAST SLOPES THIS AFTERNOON. AS SUCH, HAVE ADDED A MENTION OF
SLIGHT CHANCE THUNDER TO THIS ZONE. SNOW LEVELS WERE A BIT HIGHER
THIS MORNING AND HAVE ADJUSTED SNOW LEVELS THROUGH TODAY. LOCATIONS
ABOVE 4500 FEET AND UNDER THE MAIN PRECIP BAND WILL STILL SEE DECENT
SNOW AMOUNTS. WILL THEREFORE CONTINUE ALL CURRENT HIGHLIGHTS. 90

.LONG TERM...PREVIOUS DISCUSSION...THE 00Z GFS AND ECMWF RUNS
INDICATE A STRONG MID/UPPER LEVEL RIDGE OF HIGH PRESSURE NEAR 130W
WITH NORTHERLY FLOW ALOFT ON THE EASTERN FLANK OF THE RIDGE ACROSS
THE PACIFIC NORTHWEST. THE GFS RUN SHOWS A WEAK TROUGH MOVING SOUTH
IN THIS NORTHERLY FLOW INTO WASHINGTON OVERNIGHT AS DOES THE ECMWF,
BUT THE ECMWF SHOWS THE TROUGH WITH CONSIDERABLY MORE AMPLITUDE AND
THUS MORE PRECIP SPREADING SOUTH ALONG THE CASCADES OVERNIGHT. AS
SUCH I SPLIT THE DIFFERENCE AND WENT WITH A SLIGHT CHANCE OF PRECIP
ALONG THE EAST SLOPES OF THE WASHINGTON CASCADES FOR SUNDAY NIGHT.
ON MONDAY THE ECMWF SHOWS THE TROUGH REMAINING OVER THE REGION SO I
KEPT CHANCE POPS FOR THE MOUNTAINS FOR MONDAY THROUGH MONDAY NIGHT.
TUESDAY THE NORTHERLY FLOW ALOFT CONTINUES AND THUS KEEPS A LOW
CHANCE OF SHOWERS IN THE BLUE MOUNTAINS. TUESDAY NIGHT ONWARD A
DRIER NORTHERLY FLOW USHERS IN A DRYING TREND WHICH PERSIST THROUGH
THURSDAY.

&&

.AVIATION...18Z TAFS...RAIN HAS OVERSPREAD KYKM AND KDLS CAUSING
MVFR/IFR CEILINGS. THE RAIN MAY SPREAD FAR ENOUGH EAST LATER THIS
MORNING TO REACH KPDT...BUT KALW AND KPSC SHOULD REMAIN DRY. RAIN
WILL MOVE INTO KRDM AND KBDN AROUND 00Z...AND CHANGE OVER TO SNOW
LATER IN THE EVENING. WINDS WILL BECOME NORTHERLY AT MOST LOCATIONS
AND INCREASE TO 10-20 KTS. 82

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  48  27  39  21 /  40  30  10   0
ALW  52  30  42  24 /  20  30  10   0
PSC  55  31  47  23 /  30  20  10   0
YKM  50  29  44  23 /  70  30  10   0
HRI  51  29  45  22 /  50  30  10   0
ELN  51  28  44  22 /  70  30  10   0
RDM  44  22  33  12 /  70  60  30   0
LGD  45  26  38  18 /  50  50  20   0
GCD  44  26  34   9 /  90  80  40   0
DLS  50  32  47  27 /  70  40  20   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WARNING UNTIL 7 AM PST SATURDAY ORZ506.

     WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST
     SATURDAY ORZ511.

     WINTER WEATHER ADVISORY UNTIL 7 AM PST SATURDAY ORZ505.

     WINTER WEATHER ADVISORY UNTIL 4 AM PST SATURDAY ORZ503.

     WINTER WEATHER ADVISORY UNTIL 4 AM PST SATURDAY ORZ509.

WA...NONE.
&&

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

$$

90/99/82







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.