textproduct: Pendleton

Updated for Aviation

DISCUSSION...Fog still lingers throughout parts of the Foothills of the Blues and Kittitas Valley through the rest of the morning. Precaution should be given in areas of very dense fog and freezing fog. Even given the stratus cloud cover, temperatures will efficiently cool enough, thanks to light winds, to bring saturation in many areas, especially the lower valleys, plumes of fog through the night. We'll continue to see temperatures drop region wide to below freezing, with lower valleys have a bit shorter on the confidence side that they'll drop below freezing and instead hover around the low to mid 30s (40-60% chance for Valleys staying above freezing, and >85% chance for higher elevations dropping below freezing). Otherwise, upper level dry northwest winds will keep conditions dry for the rest of the night. Unsettled weather continues later in the late morning hours to early afternoon when a trough deepens in central Canada, allowing shortwaves to form valley rain and snow/wintry mix in the higher elevations.

We'll have a constant stream of instability with surface southwest flow, allowing a continuous stream of wetter/warmer weather through the beginning of next week. Heaviest QPF amounts will be located in the mountains, with three day totaling up to 3 inches in the highest elevations (50-70 percent chance) with the lower elevations that include the Basin, Central Oregon, and the Kittitas Valleys seeing up to a quarter of an inch of rain, more so than where the heaviest rain bands occur (40-60 percent chance). A warm trend will begin on Friday with high temperatures rising to low to mid 50s and continue on through next week as well. This will cause some hydro and river level concerns going through Wednesday with the snow falling between now and then, although guidance at this time does not have some rivers going beyond 'Action' stage, it is something to keep an eye for the next couple of days.

Breezy to windy conditions will be observed with the upcoming system, with the strongest winds occurring between Friday night and Saturday morning. Parts of the Columbia Basin, Foothills, and other lower elevation areas will see gusts up to 30 to 40 mph for much of the time. NBM advertising 40 to 60 percent chances of wind advisory conditions over the weekend, with 10 to 30 percent chances of gusts 57 mph or greater. No wind highlights expected yet, but confidence is increasing slightly for Wind Advisory thresholds, the question will be if they mix down enough to the surface to exceed advisory thresholds.

AVIATION...12Z TAFS...Conditions range from VFR to LIFR early this morning. Both ALW, PDT and YKM are LIFR in fog and stratus once again, while BDN and RDM are VFR, with the other sites mostly MVFR. Expect slow improvement (if any) at PDT and ALW.

RA is expected to overspread the region later this morning and then will continue through the afternoon and into the evening. Depending on location additional RA is anticipated overnight. With the RA will come more reduced CIGS/VSBYS and even BDN and RDM will have MVFR this evening and overnight.

Winds are expected to remain light.

PRELIMINARY POINT TEMPS/POPS

PDT 42 37 54 41 / 90 80 90 50 ALW 41 38 51 42 / 90 90 100 70 PSC 40 33 53 41 / 80 70 70 20 YKM 41 30 51 39 / 50 50 70 50 HRI 41 36 55 43 / 90 70 80 30 ELN 41 33 46 35 / 60 60 80 60 RDM 46 35 56 34 / 50 50 70 30 LGD 40 35 49 39 / 90 90 100 80 GCD 42 37 48 36 / 80 90 90 50 DLS 46 42 56 47 / 80 80 90 80

PDT WATCHES/WARNINGS/ADVISORIES

OR...Dense Fog Advisory until 11 AM PST this morning for ORZ507.

WA...Dense Fog Advisory until 11 AM PST this morning for WAZ029.

Freezing Fog Advisory until 11 AM PST this morning for WAZ026- 027.