textproduct: Pendleton

DISCUSSION

Satellite shows stratus continuing to cover much of the Columbia Basin and into the Yakima/Kittitas region through the afternoon hours. Region is still dominated by high pressure and a ridge just west of the area, bringing cool pooling and subsidence. Despite some northward cool/dry air, it doesn't help mix the surface enough to make the stratus dissipate. The pattern is looking to continue at least over the next couple of days of low stratus/fog in the lower regions. The dominant ridge looks to stay through at least early next week, which will also bring some air stagnation concerns along the lower areas of the region through at least Tuesday afternoon. Ridge will begin to erode Sunday to Monday, before bringing a more mixed environment going into Tuesday evening.

Otherwise, we'll continue to see areas of widespread fog/freezing fog, especially through the morning hours to afternoon develop, making roads harder to navigate in general and possibly more slick due to the freezing temps. Winds remain light and variable for the most part through the next several days. The pattern may begin to shift through mid-next week as the ridge de-amplifys (60-80 percent chance) and mountain rain/snow showers start to come back into the picture, but will need to inch closer to the event before we have a better picture of the overall set-up.

AVIATION...00z TAFs

After a brief period of improved conditions this afternoon, the next round of fog will be developing this evening. MVFR to IFR with pockets of LIFR conditions will be possible after 03z for Washington terminals KPSC, KYKM, and KALW. The onset for the next round of fog is favored to be after 12z Friday for Oregon terminals KPDT and KDLS. As fog dissipates after 21z on Friday, building high pressure will bring a return of widespread VFR conditions.

Central Oregon terminals (KRDM and KBDN) are expected to remain VFR through the TAF period.Branham/76

PRELIMINARY POINT TEMPS/POPS

PDT 27 38 24 38 / 0 0 0 0 ALW 30 38 27 38 / 0 0 0 0 PSC 28 40 27 39 / 0 0 0 0 YKM 28 43 26 42 / 0 0 0 0 HRI 27 40 26 38 / 0 0 0 0 ELN 27 40 25 39 / 0 0 0 0 RDM 21 40 19 46 / 0 0 0 0 LGD 28 46 27 47 / 0 0 0 0 GCD 29 51 29 53 / 0 0 0 0 DLS 32 43 30 42 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

OR...Air Stagnation Advisory until 4 PM PST Tuesday for ORZ041-044- 507-508-510-511.

Dense Fog Advisory until 4 PM PST this afternoon for ORZ507.

WA...Air Stagnation Advisory until 4 PM PST Tuesday for WAZ024- 026>029-521.

Dense Fog Advisory until 4 PM PST this afternoon for WAZ026-027.