756 FXUS66 KPDT 100550 AAA AFDPDT Area Forecast Discussion...Updated National Weather Service Pendleton OR 1049 PM PDT Tue Oct 9 2018 Updated aviation discussion .UPDATE...An upper low that moved through the area earlier today has moved to near the Idaho/Nevada/Utah border and will continue to move southeast and away from us. Some wraparound moisture is giving us lingering light rain showers over much of the Oregon portion of the area. The showers should taper off in the next few hours but may last through the night in Wallowa county. Have made some adjustments to the forecast to match precipitation trends. Skies will be clearing from the north and becoming mostly clear late tonight. With winds becoming light, this will create good conditions for radiative cooling. Temperatures should be about 10 degrees cooler than last night with many mountain locations below freezing. The rest of the area will be in the mid 30s to mid 40s. The cooler temperatures along with the abundant moisture from the rain earlier today will likely lead to the development of patchy fog overnight in fog prone locations. Have made some temperature and sky cover adjustments, but overall the forecast was in generally good shape. Forecast update already out. Perry && AVIATION...06Z TAFs...Isolated showers will continue from the Blue Mountains eastward for a few more hours before ending. Have carried -SHRA at KPDT through 07Z due to the persistent nature of the light showers there. Skies will be clearing from north to south and with good cooling and light winds, fog formation is possible at most TAF sites later tonight. Have MVFR ceilings and visibilities at KRDM and KBDN 08Z-15Z and similar tempos at other TAF sites except for KYKM and KPSC. Skies will clear tomorrow afternoon and evening. Winds will remain below 12 kts for the next 24 hours. Perry && .PREV DISCUSSION... /issued 345 PM PDT Tue Oct 9 2018/ SHORT TERM...Today through Thursday...An upper level low moved from Moses Lake WA to southeast ID. Precipitation has tapered down to isolated to scattered showers, mainly in the mountains. Precipitation will continue to decrease through the evening as the low moves farther away. Snow levels will be near 5000 ft, so minor accumulations are possible. By midnight skies will begin to clear as northerly low level flow develops. Patchy fog or freezing fog will develop late tonight due to radiational cooling and very moist ground. Wednesday night an upper level ridge will build over WA and then into OR. With a building ridge clear skies and light winds will strong radiational cooling will occur. Thursday morning low temperatures will be near freezing in the Columbia Basin and Blue Mountains Foothills so Freeze Warnings may be necessary. Patchy fog or freezing fog will develop again early Thursday morning as well. Coonfield LONG TERM...Thursday night through Tuesday. Large upper level ridge will control the weather pattern for the Pacific northwest through the extended time period. The upper level flow will be northerly with some occasional cirrus moving through. Otherwise sunny days with highs in the 50s and 60s. Clear cool nights with lows in the 20s and 30s. Surface winds will be mainly north to northeast as the pattern favors offshore low level flow. 94 94 && .PRELIMINARY POINT TEMPS/POPS... PDT 39 56 33 58 / 30 10 0 0 ALW 42 58 37 60 / 20 10 0 0 PSC 40 61 34 63 / 10 0 0 0 YKM 40 61 32 64 / 10 0 0 0 HRI 40 61 34 63 / 10 0 0 0 ELN 39 60 33 63 / 10 0 0 0 RDM 34 57 26 58 / 10 10 0 0 LGD 38 54 31 57 / 40 10 10 0 GCD 37 53 31 59 / 40 10 10 0 DLS 45 64 39 67 / 20 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ 83/94/83