Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
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641 FXUS66 KPDT 181707 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1007 AM PDT Tue Jun 18 2024 Updated Aviation Discussion .AVIATION...18Z TAFS...All sites prevail at VFR for this period with current clear skies and light winds. KPDT and KALW will have few cumulus clouds passing through this afternoon and evening (40-50% confidence). Feaster/97 && .PREV DISCUSSION... /issued 223 AM PDT Tue Jun 18 2024/ .SHORT TERM...Today through Thursday... Bottom Line Up Front 1. Dry and warm conditions favor the period with slight chances of mountain showers/thunderstorms 2. A thermal trough will bring warm temperatures to the region by midweek Models show the upper level low that has been over the area is moving off to the east taking the cooler air along with it. Precipitation will diminish leaving only a slight chance (less than 30%) of showers and thunderstorm over the eastern mountains of Wallowa County and showers along the WA Cascades before clearing out completely this afternoon. Model derived soundings show the eastern portion of Wallowa County will see MUCAPE up to 400 J/kg, lapse rates of 8.4 C/km, lifted index of -2, however, bulk shear is low at 15 kts. With that said, can not rule out an occasional roll of thunder of flash of lighting along the far eastern mountains this afternoon. Once the trough exists later in the afternoon, early evening, models show the upper level flow to turn more zonal. Drier conditions will accompany the zonal flow. Looking at the surface, models do show a weak thermal trough wiggling its way northward and in place over the area by Wednesday bringing with it much warmer temperatures. EFI shows temperatures are still near normal to just below normal remaining a bit on the cooler side today with 79% of the raw ensembles showing Pendleton and Central Or to be in the mid 60s to low 70s, the Gorge and Basins in the mid to upper 70s with the higher terrains in the mid to upper 50s. As the thermal through moves overhead by Wednesday, temperatures will increase nearly 10 degrees with over 70% of the raw ensembles showing Pendleton and central OR in the upper 70s to low 80s, the Gorge and Basins in the low to mid 80s and the higher terrains in the mid 60s. Thursday temperatures will be 2 to 5 degrees warmer. 65% of the raw ensembles show Pendleton and central OR in the mid to upper 80s, the Gorge and Basins in the low 90s and the higher terrains in the upper 60s to low 70s. Bennese/90 .LONG TERM...Friday through Monday..A trough over the area early Friday will give way to a ridge which will remain over the area Saturday before moving eastward on Sunday as a cold front and upper trough move into the Pacific Northwest. Hot temperatures are expected Friday and Saturday with highs 10 to 15 degrees above normal. Highs will mainly be in the upper 80s to lower 90s on Friday and in the 90s on Saturday. The trough will bring some precipitation potential to the Washington Cascades, but the rest of the area will remain dry. The low rain chances will remain over the Washington Cascades through Monday, but little if, any rain is expected across the majority of the area through the extended period. High temperatures will be closer to normal (though still above) on Sunday, then a few degrees below normal on Monday before returning to close to or slightly above normal on Tuesday. Sunday`s highs will generally be in the low to mid 80s. On Monday high temperatures will be in the upper 70s to lower 80s and then back in the 80s on Tuesday. Winds are expected to be mainly light through the period, though they will be a bit breezy later Saturday and especially Sunday with the passage of the front and with the trough moving across. Overall, model guidance is in generally good agreement through Tuesday, when disagreement becomes more substantial. THe ECMWF deterministic has a more zonal pattern while the GFS has another trough approaching. The ensemble clusters show a bit more support for the ECMWF with 33% supporting its solution, though the clusters are fairly even split for the other model solutions. Of course there is natural variability in the guidance at this time range. && .PRELIMINARY POINT TEMPS/POPS... PDT 73 45 83 51 / 0 0 0 0 ALW 76 48 85 54 / 0 0 0 0 PSC 78 49 87 55 / 0 0 0 0 YKM 76 47 84 53 / 0 0 0 0 HRI 78 48 88 53 / 0 0 0 0 ELN 76 46 82 51 / 10 0 0 0 RDM 72 39 81 46 / 0 0 0 0 LGD 68 41 78 47 / 10 0 0 0 GCD 70 41 80 48 / 0 0 0 0 DLS 78 52 88 58 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...90 LONG TERM....77 AVIATION...97