FXUS66 KPDT 201752

AFDPDT



Area Forecast Discussion

National Weather Service Pendleton OR

1052 AM PDT Fri Mar 20 2026



.KEY MESSAGES...



1. Cascade rain will persist through today



2. Above-average temperatures today



3. A system will bring temperatures back to seasonal averages 

   Saturday with mountain precipitation continuing



&&



.DISCUSSION...issued 313 AM PDT Fri Mar 20 2026...

Current radar shows a few returns over the WA Cascades as the 

remnants of the atmospheric river remain over the area. Current

ground observations show that the last hour these returns have 

only put down between 0.10-0.12 inches of rain. Rain is expected

to continue over the mountains through today (Friday) with rain

accumulations nearing 0.4-0.8 inches through 5 AM (70-90% 

confidence). Snow levels will begin to drop steadily through 

Friday and Saturday bottoming out at around 2500 feet. This 

front will also be bringing cooler temperatures back to the 

mountains with light high elevation mountain snow with 

accumulations of 0.10-0.30 inches above 4000 feet (70-90% 

confidence).



Models show an upper level ridge still over the region. This is

what is bringing the above average temperatures. In house 

comparisons for temperatures shows that temperatures Friday 

remain anywhere between 20-25 degrees above normal with even the

higher elevations seeing above average temperatures. Models 

show the ridge to remain in place through at least Friday night 

ahead of a pattern change. Temperatures will remain above 

seasonal average through Friday with temperatures remaining in 

the low to mid 70s across the region with 90-100% of the NBM raw

ensembles in agreement. Friday temperatures will remain in the 

mid 70s for much of the region with again 90-100% of the raw 

ensembles in agreement. 



Friday night into Saturday models are in firm agreement with a

weak upper level trough sweeping into the region followed by 

zonal flow. NBM shows snow levels to begin to decrease as the 

system moves across and temperatures will decrease to near 

seasonal average. Mountain precipitation is expected with this 

system with very light (0.01-0.03 inches) snow accumulations 

expected (80-90% confidence) along the crests of the Cascades 

while lower elevations along the east slopes will see a 

rain/snow mix. Models show much of the precipitation to 

primarily along the OR Cascades and the foothills of the Blues 

and the Blue Mountains Saturday with rain amounts of 0.05-0.10 

inches (60-80% confidence). Temperatures will decrease by nearly 

20 degrees Saturday with localized highs in the low 60s in the 

Basin and mid to upper 50s elsewhere (70-80% confidence).



&&



.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...

VFR conditions are forecast today as a ridge of high pressure 

remains over the region. CIGs will be mostly 15-25 kft through 

afternoon, though mountain waves may induce periodic BKN060 to 

BKN080 decks at DLS/YKM. 



This evening through Saturday morning, a cold front will sag 

southeastward across the region, bringing low (10-30 percent) 

chances of light rain for DLS/YKM/RDM/BDN/PSC and medium-high 

(30-70 percent) chances at PDT/ALW. Forecast soundings from the 

12Z HREF suggest at least some potential for MVFR CIGs, highest 

chances at PDT/ALW, but have not advertised in the 18Z TAFs yet 

due to lack of confidence.



Winds of 10-15 kts with gusts of 15-25 kts are forecast for all

sites. 86



&&



.FIRE WEATHER...

An SPS is out for elevated fire weather conditions for Ochoco-

John Day Highlands and central OR. A strong ridge of high 

pressure has lead to well above average temperatures as well as

very low relative humidities (80-90% confidence)for portions of

central OR and the eastern mountains. Additionally, diurnal 

winds have the capabilities of reaching 20 to 30 mph gusts 

(50-70% confidence). The combination of dry conditions and 

elevated winds can lead to rapid fire spread. 90



&&



.Preliminary Point Temps/PoPs...

PDT  75  46  58  31 /  10  40  40   0 

ALW  74  48  59  35 /  10  50  60   0 

PSC  76  47  64  34 /  10  30  20   0 

YKM  71  41  59  30 /  30  20   0   0 

HRI  76  48  63  32 /  10  30  20   0 

ELN  60  37  51  29 /  50  20   0   0 

RDM  76  43  58  24 /   0  10  10   0 

LGD  78  45  56  29 /   0  30  70  10 

GCD  77  46  56  29 /   0  10  50   0 

DLS  70  46  60  34 /  20  30  10   0 



&&



.PDT WATCHES/WARNINGS/ADVISORIES...

WA...None.

OR...None.



&&



$$



DISCUSSION...90

AVIATION...86

FIRE WEATHER...90