332 FXUS66 KPDT 110332 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 832 PM PDT Wed Oct 10 2018 .UPDATE...High pressure offshore is building over the area and developing a dry northerly flow out of British Columbia. This drier air is eroding the cloudiness that had been persistent earlier today. Much of the area has cleared out aside from the Washington Cascades East Slopes, Central Oregon, the Ochoco-John Day Highlands and areas east of the Blue Mountains. Expect those areas will largely clear out later tonight. Have adjusted cloud cover to match the clearing trend. The clear skies and light winds will lead to colder temperatures late tonight. Current freeze warning for most of the lower elevations looks good. Did lower temperatures a couple of degrees in Central Oregon and the Ochoco- John Day Highlands but left other areas as is. Other than cloud cover and temperatures, the forecast was in good shape and was unchanged. Perry && .PREV DISCUSSION... /issued 325 PM PDT Wed Oct 10 2018/ SHORT TERM...Tonight through Saturday. Satellite shows clouds are clearing out of the Columbia basin and adjacent valleys this afternoon. Expect mainly clear skies here overnight. Patchy fog may develop late as ground is wet from previous rainfall. Areas of frost possible as well and will issue a freeze warning. Upslope northerly flow into the Blues and central Oregon will maintain mostly cloudy skies through the evening then gradual clearing overnight. Overnight lows will be in the 20s to mid 30s. Otherwise a large upper level ridge will be over the region Thursday through Saturday. Some cirrus moving through at times in the northwesterly flow aloft. Expect sunny days with highs in the 50s and 60s. Clear cool nights with lows in the 20s and 30s. 94 LONG TERM...Saturday night through Wednesday...A strong upper level ridge will build into WA and OR Saturday night and Sunday. The ridge axis will shift from the coast Monday afternoon to ID Wednesday. Skies will remain mainly clear through the period. High t Temperatures will be near seasonal levels with highs in the 50s and 60s. With light winds and clear skies strong inversions will form due to radiational cooling in valley locations. That will will keep morning lows cold. I added patchy late night and early morning fog to parts of the Lower Columbia Basin and Kittitas Valley Tuesday and Wednesday based on the ridge overhead strengthening surface inversions and tendency for fog to develop under strong inversions as nights get longer. Coonfield AVIATION...00Z TAFs. VFR conditions will prevail across the region. Clouds clearing from the north this evening. Winds under 12 kts. 76 && .PRELIMINARY POINT TEMPS/POPS... PDT 33 60 36 66 / 0 0 0 0 ALW 36 62 38 66 / 0 0 0 0 PSC 33 64 37 69 / 0 0 0 0 YKM 33 65 36 69 / 0 0 0 0 HRI 33 63 35 69 / 0 0 0 0 ELN 33 63 36 66 / 0 0 0 0 RDM 28 62 27 69 / 0 0 0 0 LGD 34 58 30 63 / 10 0 0 0 GCD 32 57 30 63 / 10 0 0 0 DLS 38 67 39 70 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Freeze Warning from 2 AM to 8 AM PDT Thursday for ORZ044-507-508- 510. WA...Freeze Warning from 2 AM to 8 AM PDT Thursday for WAZ026>029-521. && $$ 83/76/76