Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
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824 FXUS66 KPDT 190511 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1011 PM PDT Tue Jun 18 2024 Updated Aviation Discussion .AVIATION...06z TAFs...VFR conditions expected. Skies will continue to clear overnight, leaving us with light, terrain-driven winds less than 10 kts, shifting more north and east during the day Wednesday. Evans/74 && .PREV DISCUSSION... /issued 757 PM PDT Tue Jun 18 2024/ EVENING UPDATE...Showers and thunderstorms are winding down over the Washington Cascades and eastern mountains as drier NW flow aloft moves in over the forecast area. Storm activity has been isolated in nature, but has produced a few flashes and strikes across mainly the central WA Cascades. The weather over the next couple of days looks quiet as a mix of weak troughing and zonal flow takes hold of the PacNW. Added mention of isolated t-storms over the Washington Cascades earlier as there was no prior mention in the forecast package, but otherwise no changes were made. Evans/74 PREV DISCUSSION... /issued 247 PM PDT Tue Jun 18 2024/ SHORT TERM...Tonight through Thursday...The upper level trough over the western USA remains in place with the current trough axis just east of the forecast area. Some weak instability remains over the forecast area today that is leading to some shallow convective showers mainly over the eastern mountains and the east slopes of the Washington Cascades. This includes a slight chance (15% or less) of thunderstorms over the eastern mountains. These showers will continue into the evening then dissipate towards sunset followed by clearing skies. The main energy in the upper level trough will continue to move east over the next couple of days leaving a weak upper level trough over the region Wednesday and Thursday. This translates to mostly clear skies and light winds with temperatures continuing to warm each day. High temperatures around the Columbia Basin will be in the 80s Wednesday and then the upper 80s to lower 90s on Thursday while mountains will see 70s Wednesday and 70s to low 80s Thursday. LONG TERM...Friday through Tuesday... Key Messages: 1. Dry, warm conditions through Saturday 2. Breezy to locally windy conditions this weekend A transient trough will be exiting the PacNW Friday allowing an upper ridge to build over the region Saturday. Then, another trough off the coast moves across PacNW Sunday, driven by a closed low moving into British Columbia. Monday through Tuesday, the region will then enter a zonal pattern before another weak upper level trough off the coast puts us back under a southwest flow Tuesday night. No chances of precip due to dry, warm conditions for the extended period. Mountain showers are possible at the crest of WA Cascades Sunday through Monday, but chance are low (<20%). Breezy conditions for Yakima Valley, Simcoe Highlands, Foothills, and Kittitas Valley will occur with wind gusts at 20-30 mph for Saturday night into Sunday morning (>70% chance). However, wind gusts could exceed to 40-45 mph Sunday afternoon into night for these areas thus extending to portions of Columbia Basin. Sunday confidence increases as surface pressure gradient strengthens with the trough arriving from the backside of the transient ridge. Winds will decrease first the week but breezy winds continue across the forecast area with wind gusts at around 15-25 mph (40-50% confidence). High temperatures for Friday through Saturday will be above normal in the low 90s around the Columbia Basin and mid to upper 80s for the remaining forecast area. With the arrival of the upper level trough on Sunday temperatures will cool by few degrees through Monday before warming up again Tuesday. Feaster/97 && .PRELIMINARY POINT TEMPS/POPS... PDT 46 83 51 88 / 0 0 0 0 ALW 49 86 54 91 / 10 0 0 0 PSC 50 87 56 93 / 0 0 0 0 YKM 49 84 55 89 / 10 0 0 0 HRI 50 89 54 94 / 0 0 0 0 ELN 48 80 52 85 / 10 0 0 0 RDM 41 82 47 84 / 0 0 0 0 LGD 42 78 48 84 / 20 0 0 0 GCD 43 81 49 86 / 10 0 0 0 DLS 53 88 59 92 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...74 LONG TERM....97 AVIATION...74