907
FXUS66 KPDT 201822
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1022 AM PST TUE JAN 20 2026
AVIATION...18Z TAFS
AFTER A BRIEF REPRIEVE FROM THE FOG AND
STRATUS AT BDN/RDM OVERNIGHT INTO THE EARLY MORNING HOURS, A SURGE
OF NORTH TO NORTHWEST WINDS HAS BROUGHT FZFG AND LIFR STRATUS BACK
TO BOTH SITES. WHILE THERE IS POTENTIAL FOR ENTRAINMENT OF DRIER
AIR TO ERODE THE STRATUS DECK IN PLACES, ESPECIALLY FOR CENTRAL
OREGON SITES, CONFIDENCE IN THIS SCENARIO WAS TOO LOW (5-30%
DEPENDING ON TAF SITE) TO SHOW AN IMPROVEMENT IN CIGS/VSBYS THIS
AFTERNOON THROUGH WEDNESDAY MORNING. IN FACT, 06Z AND 12Z CAMS
SUGGEST A BETTER CHANCE FOR A RETURN OF SOME FZFG OVERNIGHT INTO
WEDNESDAY MORNING, WITH THE HIGHEST CONFIDENCE 40-60% AT
PDT/ALW/RDM.
WINDS OF 10 KTS OR LESS ARE FORECAST FOR ALL SITES THE REMAINDER
OF THE PERIOD.
PREV DISCUSSION
/ISSUED 242 AM PST TUE JAN 20 2026/
DISCUSSION...OVERNIGHT SATELLITE IMAGERY SHOWS A LOW STRATUS DECK
PERSISTING OVER MUCH OF THE LOWER ELEVATION AND VALLEY ZONES OF
OUR FORECAST AREA. THE REGION REMAINS LOCKED INTO A STAGNANT HIGH
PRESSURE PATTERN THAT WILL GRADUALLY EVOLVE DURING THE LATER HALF
OF THE WORK WEEK, BUT FOR NOW, EXPECT MOST OF OUR POPULATION
CENTERS TO CONTINUE TO STRUGGLE SEEING THE SUNLIGHT. WE ARE SEEING
SOME GRADUAL RETREAT OF THE LOW CLOUD DECK AWAY FROM CENTRAL
OREGON EARLY THIS MORNING, BUT THIS COULD VERY WELL RETURN GIVEN
HOW THE SYNOPTIC PATTERN IS EXPECTED TO EVOLVE THROUGH THE MIDWEEK
(30-40% CONFIDENCE).
LOOKING AT THE BIG PICTURE, A WEAK NW FLOW REGIME WILL REMAIN IN
PLACE THROUGH THE MIDWEEK. THIS WILL ALLOW THE CURRENT STRATUS
DECK TO PERSIST WHERE IT IS CURRENTLY LOCATED, WITH ANY FLUX IN
ITS EXTENT MOST LIKELY TO OCCUR IN CENTRAL OREGON, WHICH WE'VE
OBSERVED OVER THE LAST FEW DAYS. OTHERWISE, THE STRATUS DECK HAS
MORE OR LESS EXPANDED TO ITS MAXIMUM EXTENT, SO DON'T EXPECT THE
COLUMBIA BASIN TO SEE SUN AGAIN UNTIL AT LEAST THE END OF THE WORK
WEEK. WHAT MAY FINALLY BREAK US FREE FROM THE GRASP OF THIS
GLOOM? GLOBAL MODELS DEPICT A LARGE LOW PRESSURE SYSTEM OVER
EASTERN CANADA - SO LARGE THAT IT INTRODUCES A WEAK OPEN WAVE OVER
THE PACNW. SHOULD NOTE THAT CONFIDENCE IS STILL RELATIVELY LOW
(30-40%) THAT THIS SYSTEM WILL PRODUCE ENOUGH MECHANICAL MIXING TO
FINALLY LIFT US OUT OF THIS PATTERN, BUT IT'S STILL THE MOST
NOTABLE SYNOPTIC FEATURE SEEN IN THE REGION OVER THE LAST WEEK AND
A HALF. AT THIS POINT, WE'LL TAKE ANYTHING JUST TO SEE BLUE SKY
AGAIN.
KEEPING AN EYE ON WEBCAMS OVERNIGHT, THUS FAR FOG COVERAGE IS
PATCHY ENOUGH TO PRECLUDE ANY ADVISORIES, BUT WILL KEEP AN EYE
ON NORTH CENTRAL OREGON IN PARTICULAR, WHERE A FEW SPOTS ON US97
LOOK PRETTY SOCKED IN. PRECIP WISE, HOWEVER, THREATS ARE PRETTY
MINIMAL UNTIL AT LEAST EARLY NEXT WEEK, WHERE ENSEMBLES HINT AT
PERHAPS A MORE PROGRESSIVE PATTERN FINALLY TAKING OVER. 74
PRELIMINARY POINT TEMPS/POPS
PDT 31 23 32 21 / 0 0 0 0
ALW 32 26 32 23 / 0 0 0 0
PSC 36 25 35 24 / 0 0 0 0
YKM 37 24 35 21 / 0 0 0 0
HRI 34 25 33 22 / 0 0 0 0
ELN 32 22 33 20 / 0 0 0 0
RDM 38 19 39 18 / 0 0 0 0
LGD 39 19 40 22 / 0 0 0 0
GCD 47 22 47 25 / 0 0 0 0
DLS 36 29 37 26 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...AIR STAGNATION ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ041-
044-507-508-510-511.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR ORZ510.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-
026>029-521.
DISCUSSION...74
AVIATION...86
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