Scientific Forecaster Discussion
000 FXUS66 KPDT 180916 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 217 AM PDT Sat Aug 18 2018 .SHORT TERM...Today through Monday...A ridge of high pressure will be over the region through midday Sunday. Expect a nice day today with Sunny skies and warm temperatures. Highs will be 90-95 lower elevations and 80-85 mountains. It will be clear and cool tonight with lows 55-60 in the lower elevations and 45-50 mountains. It will be mostly sunny and hot on Sunday with temperatures a couple of degrees warmer than today. A trough of low pressure will be approaching the area toward evening. After 5-7 pm there will be a slight chance of thunderstorms from the central into the northeast mountains. Storms are not expected to be strong or severe. A few showers will linger overnight Sunday into Monday morning with a slight chance for thunderstorms east Monday afternoon. Highs on Monday will be in the lower to mid 90s in the lower elevations and in the lower to mid 80s mountains. There should be a bit less smoke and haze around the next couple of days but it could increase from the Canadian fires on Monday as the flow turns northeasterly. 78 .LONG TERM...Monday night through Saturday...Models continue to suggest a rather low amplitude and active pattern through the middle of next week over the Pacific Northwest with systems undercutting the broader ridging extending up into Alaska. Multiple models show decent mid-level moistening in northeasterly flow across a bulk of the area Monday evening as a weak disturbance back builds into the area from the east but think this may be a little overdone and have confined a slight chance of thunderstorms primarily in the eastern mountains for now. Operational models are much more modest in any mid-level moisture for Tuesday afternoon, but ensembles continue to hint at just enough to justify an additional round of afternoon slight chance thunderstorm PoPs across similar areas - even less confidence in this. With north/northeasterly flow with both of these weak systems will likely see haze/smoke from Canadian fires returning to the area early next week. The overarching ridge begins to break down toward the end of the week with dry and (hopefully) smoke free westerly flow bringing a slight cooling trend. Peck && .AVIATION...12Z TAFs...Mostly clear skies with winds generally less than 10 KTs. Will see one more day of nearly unrestricted visibility in hazy skies before conditions begin to worsen again into early next week. && .PRELIMINARY POINT TEMPS/POPS... PDT 90 62 94 62 / 0 0 0 10 ALW 92 61 95 62 / 0 0 0 0 PSC 93 59 95 61 / 0 0 0 0 YKM 92 60 93 61 / 0 0 0 0 HRI 93 59 95 61 / 0 0 0 0 ELN 92 58 93 59 / 0 0 0 0 RDM 91 50 91 53 / 0 0 0 20 LGD 89 52 92 57 / 0 0 0 20 GCD 90 57 93 58 / 0 0 0 20 DLS 93 63 95 65 / 0 0 0 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None.