579
FXUS66 KPDT 272234
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
234 PM PST THU NOV 27 2025
DISCUSSION
SKIES HAVE PARTIALLY CLEARED ACROSS THE FORECAST AREA
THIS AFTERNOON IN THE WAKE OF A WARM FRONT PUSHING THROUGH THE
REGION AND BRINGING A ROUND OF SHOWERS TO PRIMARILY THE WA HALF OF
THE CWA. THIS FRONT STEMS FROM A DEFINED LOW PRESSURE SYSTEM,
CURRENTLY BEARING DOWN ON THE WA COAST PER VISIBLE SATELLITE
IMAGERY, WHICH WILL USHER IN A COLDER WEATHER PATTERN THROUGH THE
NEXT WEEK ONCE IT MOVES ONSHORE. AS IT DOES SO, THE AFOREMENTIONED
WARM FRONT WILL OCCLUDE, BRINGING ANOTHER ROUND OF SHOWERS TO (AGAIN)
THE WA HALF OF THE FORECAST AREA THIS EVENING AND OVERNIGHT.
THE LOW WILL GRADUALLY SHIFT SOUTHEASTWARD HEADING INTO TOMORROW
MORNING, BRINGING THIS NEXT EXPECTED BAND OF SHOWERS WITH IT,
HOWEVER GUIDANCE GENERALLY FAVORS QPF TO BE CONCENTRATED OVER THE WA
CASCADES, NORTHERN BLUES (UP TO AN INCH OF LIQUID PRECIP FOR BOTH),
AND BASIN (0.2-0.3 INCHES). COULD STILL SEE RESPECTABLE LIQUID
PRECIP AMOUNTS OVER THE OREGON BASIN AND FOOTHILLS OF THE BLUES, AS
WELL AS THE BLUES ITSELF, BUT NBM PROBABILISTIC GUIDANCE DOES SEEM
TO FAVOR A PRECIP DROPOFF ACROSS STATE LINES, WITH ABOUT A 40-50%
CHANCE FOR LIQUID PRECIP OVER A QUARTER OF AN INCH OVER THE OREGON
BASIN AND FOOTHILLS OF THE BLUES, INCREASING TO 70-80% OVER MOST OF
THE WA BASIN AND ADJACENT VALLEYS. SNOW LEVELS WILL BE ELEVATED AT
GENERALLY OVER 4000-5000 FT OVERNIGHT, SO MOUNTAIN PASS SNOW IS NOT
MUCH OF A CONCERN FOR OUR NECK OF THE WOODS.
BEHIND THIS LOW, THE SYNOPTIC FLOW ALOFT WILL SHIFT MORE
NORTHWESTERLY, INVITING COLD AIR ADVECTION TO DROP HIGH TEMPERATURES
OVER THE WEEKEND DOWN INTO THE LOWERS 40S FOR MUCH OF THE LOWER
ELEVATIONS AND VALLEYS, WITH LOWS IN THE 20S. GUIDANCE SUGGESTS A
WEAK TROUGH WILL SLIDE THROUGH THE REGION ON SATURDAY, BRINGING
LIGHT MOUNTAIN SNOW ACROSS THE AREA, HOWEVER THIS SYSTEM WILL BE
LACKING IN MOISTURE, SO ACCUMULATIONS ARE GENERALLY EXPECTED TO BE
LESS THAN AN INCH, EVEN FOR RIDGETOPS. AFTERWARDS, ENSEMBLES KEEP US
RELATIVELY LOCKED INTO A NW FLOW REGIME FOR THE NEXT WEEK, WITH
INTERMITTENT CHANCES FOR PRECIP THROUGHOUT THE WORK WEEK. GUIDANCE
SO FAR, HOWEVER DEPICTS A GENERALLY DRY FLOW PATTERN, BUT WILL KEEP
AN EYE ON HOW THE FORECAST EVOLVES, AS SUCH PATTERNS DO INVITE THE
POTENTIAL FOR LOWLAND SNOW. 74
AVIATION...00Z TAFS
A MIX OF MVFR OR LOWER CONDITIONS ARE
EXPECTED FOR MANY SITES THROUGH THE PERIOD. CIGS HAVE IMPROVED TO
VFR AT SITES PDT/RDM/BDN/ALW, WITH MVFR TO IFR CIGS AT SITES
DLS/YKM/PSC AT THIS TIME. SITES PDT/ALW WILL SEE VSBY/CIGS
DETERIORATE AGAIN AS THE NEXT ROUND OF PRECIPITATION IMPACTS THESE
SITES AFTER 03Z. WITH ONSET OF PRECIPITATION, SITES DLS/PSC/YKM
WILL SEE VSBY DROP TO MVFR OR LOWER, WITH CIGS LOWERING FURTHER,
WITH IFR CIGS DEVELOPING AT SITE PSC AFTER 07Z. RAIN IMPACTS ARE
EXPECTED TO END BETWEEN 14-18Z AT ALL NORTHERN SITES. CIGS WILL
REMAIN LOW AT SITES PDT/ALW THROUGH THE END OF THE PERIOD, WITH
CIGS RISING TO ABOVE 3KFT AT SITES DLS/PSC AND BECOMING FEW AROUND
1.5KFT TO 2.5KFT AT SITE YKM. CIGS AT SITES RDM/BDN WILL LOWER TO
AROUND 3KFT AFTER 18Z.
WINDS WILL BE LIGHT, 12KTS OR LESS, THROUGH THE PERIOD, EXCEPT AT
SITED BDN WHERE WINDS WILL INCREASE TO 12-15KTS WITH GUSTS UP TO
25KTS UNTIL 02Z. LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 36 45 29 39 / 90 90 0 20
ALW 38 44 31 39 / 100 90 10 20
PSC 36 49 28 41 / 90 70 0 10
YKM 35 50 28 41 / 90 50 0 10
HRI 38 49 29 41 / 90 90 0 20
ELN 32 46 25 37 / 90 40 0 20
RDM 32 50 25 45 / 20 10 0 10
LGD 36 44 28 43 / 80 90 0 20
GCD 35 46 28 48 / 30 60 0 10
DLS 43 50 36 44 / 90 80 0 20
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
DISCUSSION...74
AVIATION...82
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