FXUS66 KPDT 261020
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
220 AM PST SAT DEC 26 2009
.SHORT TERM...TODAY THROUGH MONDAY...HIGH PRESSURE WILL CONTINUE TO
INFLUENCE THE REGIONS WEATHER TODAY...WITH STRONG LOW LEVEL
INVERSIONS PERSISTING OVER MUCH OF THE AREA. AS A RESULT...PATCHY
FOG AND LOW STRATUS WILL REMAIN IN PLACE FOR YET ANOTHER DAY. ON
SUNDAY...A PACIFIC TROUGH WILL SEND A SHORTWAVE INTO SOUTHERN AND
CENTRAL OREGON...WHICH COULD INDUCE A FEW SNOW SHOWERS.
HOWEVER...THIS DISTURBANCE IS NOT LIKELY TO BE STRONG ENOUGH TO
BREAK THE INVERSION...THUS FOG AND STRATUS WILL STILL BE POSSIBLE.
SNOW SHOWERS MAY LINGER THROUGH MONDAY MORNING...BUT SHOULD TAPER
OFF BY AFTERNOON AS A WEAK RIDGE OF HIGH PRESSURE BUILDS IN FROM THE
EAST. WINDS WILL BE LIGHT THROUGHOUT THE PERIOD AND TEMPERATURES
WILL REMAIN RELATIVELY COOL. 82
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY. A NUMBER OF WEAK SYSTEMS
WILL MOVE THROUGH THE REGION DURING THE PERIOD WITH TIMING
DIFFERENCES IN THE MODELS AND THE MOVEMENT OF THE SYSTEMS HARD TO
PIN DOWN. THE LOW CLOUDS AND FOG SHOULD CONTINUE IN THE LOWER
COLUMBIA BASIN THROUGH TUESDAY AND THEN AS THE UPPER LEVEL FLOW
BECOMES NORTHWEST A SLIGHT CHANCE OF SHOWERS OVER THE REGION REMAINS
ALONG THE CASCADES AND BLUE MOUNTAINS. THE FLOW TURNS BACK TO THE
SOUTHWEST WITH THE SNOW LEVELS RISING FRIDAY AND SATURDAY. AT THIS
TIME IT LOOKS STRONG ENOUGH TO CLEAR OUT THE COLD AIR IN THE LOWER
ELEVATIONS. TEMPERATURES SHOULD MODERATE A LITTLE AS THE STRONGER
SOUTHWEST FLOW BUILDS IN WITH NEAR TO ABOVE NORMAL TEMPERATURES BY
SATURDAY. ML
&&
.AVIATION...12Z TAFS. A STRONG LOW LEVEL INVERSION WILL KEEP MVFR OR
LOWER CONDITIONS GOING AT KRDM...KPDT AND KALW THROUGH THE NEXT 24
HOURS. KDLS...KYKM AND KPSC SHOULD SEE EITHER LOW VFR OR MVFR
CONDITIONS. SURFACE WINDS WILL BE LESS THAN 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 27 20 29 19 / 0 0 0 0
ALW 26 23 29 21 / 0 0 0 0
PSC 29 21 30 19 / 0 0 0 0
YKM 29 18 30 17 / 0 0 0 0
HRI 28 19 30 17 / 0 0 0 0
ELN 30 16 31 17 / 0 0 0 0
RDM 29 19 36 18 / 0 10 20 20
LGD 28 15 29 19 / 0 0 0 0
GCD 35 15 34 20 / 0 10 20 20
DLS 29 24 33 23 / 0 10 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...AIR STAGNATION ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR
ORZ041>044-049-501-504-505.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-
026>029-501-502.
&&
THREAT INDEX
TODAY : GREEN
SUNDAY : GREEN
MONDAY : 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
$$
82/93/93
