896
FXUS66 KPDT 070541
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
941 PM PST FRI FEB 6 2026
KEY MESSAGES
- HIGH PRESSURE CONTINUES WITH QUIET WEATHER AND FOG THROUGH
SATURDAY.
- FRONTAL SYSTEM WILL MOVE ACROSS THE REGION SUNDAY THROUGH MONDAY
WITH LIGHT MOUNTAIN SNOW, LOW ELEVATION RAIN AND BREEZY WINDS.
DISCUSSION
THE LOW STRATUS LAYER REMAINS LINGERING OVER THE
COLUMBIA BASIN OF WA/OR AND YAKIMA/KITTITAS VALLEYS WITH FEW TO
SCATTERED HIGH CLOUDS PASSING THROUGH, OBSERVED FROM CURRENT
SATELLITE IMAGERY. WHILE MAJORITY OF THE FOG HAS LIFTED SINCE THIS
MORNING, ROAD CAMS AND SURFACE OBSERVATIONS ARE STILL SHOWING
LOCALIZED PATCHY FOG ALONG I-84 NEAR CABBAGE HILL AND POVERTY FLATS.
SOME PARTS OF CABBAGE HILL MAY HAVE IMPROVED VISIBILITIES, BUT
EXPECT OSCILLATING VISIBILITIES AS THIS FOG REMAINS LINGERING ACROSS
MOST OF THAT AREA THROUGH THESE AFTERNOON HOURS OR EARLY EVENING IF
CONTINUES SLOSHING AROUND.
AS THIS HIGH PRESSURE SYSTEM CONTINUES THROUGH SATURDAY WITH QUIET
WEATHER, FOG WILL REMAIN AS THE MAIN CONCERN ALONG WITH THE LOW
STRATUS LAYER. BASED ON SURFACE OBSERVATIONS FOR THE PAST DAYS,
VISIBILITIES HAS BEEN TRENDING TOWARDS LESS THAN ONE HALF A MILE
ACROSS THE COLUMBIA BASIN OF WA, YAKIMA/KITTITAS VALLEYS, FOOTHILLS-
NORTHERN AND SOUTHERN BLUE MOUNTAINS OF OR EXTENDING TO CENTRAL
OREGON WITH PATCHY/AREAS OF DENSE FOG DURING OVERNIGHT AND EARLY
MORNING HOURS. THE HRW_ARW, HRW NSSL, HRRR AND NAM CONUS NEST MODELS
SHOW VISIBILITIES AT A QUARTER MILE OR LESS SLOWLY RETURNING LATER
THIS EVENING AND THEN OVERNIGHT HOURS FOR THE COLUMBIA BASIN OF
WA/OR INCLUDING YAKIMA/KITTITAS VALLEYS. CAN'T EXACTLY RULE OUT ON
HOW MUCH THE SPREAD AND STRENGTH OF THIS FOG DEVELOPMENT COULD BE,
ESPECIALLY WITH THE MODELS (NBM AND HREF) STRUGGLING TO KEEP UP.
HIGH TEMPERATURES MAY STAY MOSTLY IN THE 40S FOR THE COLUMBIA BASIN
OF WA/OR WHERE THEY WILL STRUGGLE TO INCREASE FURTHER DUE TO THE LOW
STRATUS. THE REMAINING FORECAST AREA WILL BE MAINLY IN THE 50S.
REDMOND AND BEND HAS REACHED TO THE UPPER 60S AND LOW 70S,
RESPECTIVELY YESTERDAY WHEN REDMOND HAD BROKEN THE OLD RECORD OF 67
DEGREES IN 2017 AFTER EXCEEDING TO 70 DEGREES. THE HRRR MODEL SHOW
THE TEMPS FOR REDMOND AND BEND TO BE IN THE LOW TO MID 60S TODAY,
WHICH WAS MORE REASONABLE SINCE THEY HAVE BEEN RECEIVING MORE
SURFACE DAYTIME HEATING AFTER THE LOW STRATUS LIFTED THIS MORNING.
AS RELATIVE HUMIDITIES REMAIN ELEVATED AROUND THE COLUMBIA BASIN,
THIS WILL KEEP THE LIGHT YET ONGOING MOIST AIR FOR THE LOW STRATUS
LAYER TO LAST LONGER.
SUNDAY THROUGH MONDAY, THE RIDGING PATTERN WILL THEN START TO SLOWLY
ERODE WITH THE APPROACHING SHORTWAVE AND FRONTAL SYSTEM. WIDESPREAD
PRECIP WILL DEVELOP WITH A 40-60% PROBABILITY OF 0.05 INCH AND 20-
40% PROB FOR 0.10 INCH, BASED ON THE NBM. LIGHT MOUNTAIN SNOW MIGHT
ACCUMULATE UP TO 1 INCH OF SNOWFALL SUNDAY OVER THE WA/OR CASCADES
AND SOUTHERN PARTS OF WALLOWA COUNTY (15-30% PROBAB). SNOW LEVELS
FOR SUNDAY WILL BE AROUND 4.5-7 KFT AT THE PASS LEVELS. SAME FOR
PORTIONS OF EASTERN MOUNTAINS (GRANDE RONDE VALLEY, SOUTHERN BLUE
MOUNTAINS-OR, AND JOHN DAY HIGHLANDS) AND NORTHWEST BLUES, BUT WITH
LESS THAN 0.5 INCH. AS THIS SYSTEM CONTINUES MONDAY, SNOW CHANCES
WILL SLIGHTLY INCREASE FOR THOSE AREAS WITH SNOW LEVELS DROPPING TO
2.9-3.4 KFT. SUSTAINED SOUTHWESTERLY WINDS WILL BECOME BREEZY SUNDAY
AFTERNOON INTO EARLY MONDAY MORNING AT 10-15 MPH WITH GUSTS UP TO 25
MPH FROM THE TIGHTEN SURFACE PRESSURE GRADIENTS (>50% CONFIDENCE).
FEASTER/97
AVIATION
STRATUS WILL IMPACT TERMINALS AT PSC/YKM/DLS WHILE BEING MORE
UNCERTAIN AT ALW AND PDT WHICH HAVE RECENTLY CLEARED BUT STRATUS
LINGERS NEARBY. CLEAR CONDITIONS AT RDM AND BDN SHOULD BE GOOD
FOR THE REST OF THE NIGHT AS THE HREF MEAN PROBABILITIES OF LOW
CLOUDS OR VSBY RESTRICTIONS ARE NOT REGISTERING ANY CHANCES.
MEANWHILE THE LAMP GUIDANCE DOES DROP DLS/YKM TO IFR LEVELS AS
THE BOUNDARY LAYER COOLS OVERNIGHT. EXPECT LIGHT AND VARIABLE
WINDS.
PRELIMINARY POINT TEMPS/POPS
PDT 34 53 43 53 / 0 20 60 80
ALW 37 53 45 52 / 0 20 70 90
PSC 35 50 41 52 / 0 30 50 80
YKM 34 47 37 47 / 0 40 50 60
HRI 34 49 42 52 / 0 20 60 80
ELN 33 43 34 42 / 0 60 50 60
RDM 31 56 39 52 / 0 10 40 90
LGD 35 57 42 50 / 0 10 60 90
GCD 34 58 42 52 / 0 10 40 90
DLS 38 48 44 49 / 0 60 80 90
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...AIR QUALITY ALERT UNTIL NOON PST SATURDAY FOR ORZ506-509.
DISCUSSION...97
AVIATION...71
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