FXUS66 KOTX 280452 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 952 PM PDT Fri Sep 27 2024 .SYNOPSIS... Drier and warmer weather returns to the region, with temperatures peaking on Saturday. On Sunday, another strong cold front will push through the area bringing gusty winds, blowing dust and cooler temperatures. Freezing overnight lows are expected again for much of next week, especially across the northern valleys. && .DISCUSSION... Evening update sent to issue fire weather watch for Sunday for the mentioned concerns below of strong winds and dry conditions. Many areas are also going on 30-60 days since the last wetting rain (0.10") ...STRONG COLD FRONT PASSAGE SUNDAY WITH WINDY CONDITIONS...BLOWING DUST AND ELEVATED FIRE WEATHER CONCERNS... Tonight through Sunday night: Tonight through Saturday will be fairly benign as we track a potent shortwave trough of lower pressure over the eastern Pacific. This disturbance will bring a strong cold front across the Inland Northwest Sunday morning. The approaching front will result in enhanced north to northeast winds early on in the day on Saturday down the Okanogan Valley and Purcell Trench that will spread out across the Upper Columbia Basin. Not expecting these winds to cause impacts, but will increase mixing potential with temperatures warming aloft. Highs on Saturday will be above normal with temperatures in the mid 70s to low 80s in the lee of the Cascades and mid to upper 80s over extreme eastern Washington into the Idaho Panhandle. It may very well the last widespread 80 degrees day across the Inland Northwest. Take advantage of the nice day on Saturday before the cold front arrives on Sunday. Timing of the cold front across the Inland Northwest looks to be during the morning on Sunday. Will bring strong cold air advection with a 140+ kt upper level jet at 250 mbs nosing into the Cascades for Sunday afternoon. Winds don't look to be quite as strong with this cold front compared to the previous one couple of days ago. This front will also be much drier than the previous one, and will produce much in the way of shower activity. Much drier air with the the front will mix down on the lee side of the Cascades with model guidance showing dew points plummeting into the lower 20s over a widespread area across eastern Washington into the Idaho Panhandle. There may be spots that see dew points that drop into the teens as well. Temperatures will be mush cooler with the frontal passage with afternoon temperatures only warming into the 60s to near 70s. The rapid drop in dew points will keep relative humidity low, and the windy conditions will result in an increased risk for rapid fire spread for any new or ongoing fires. Wind speeds are generally expected to range from 20 to 30 mph with wind gusts up to around 40 mph over our typical windy areas across the exposed areas of the basin. Ridge tops will see a similar potential for winds, and some enhanced gusts into mountain valleys can also be expected with good mixing coming with strong cold air advection. Wind speeds will be strong enough to result in at least patchy blowing dust across the basin. Westerly winds will transport this dust into the Spokane Area and across the Palouse with at least hazy/dusty looking skies in the Northeast Mountains and Idaho Panhandle. How the dust is lofted will be different than what was experienced on Wednesday. This is not a thunderstorm outflow convectively produced gust front where a Haboob was witnessed over the Palouse. Winds will be completely gradient driven. The sustained winds of 20-30 mph will be more significant in sustaining dust channels and there won't be rain along the front to knock down dust like the previous front brought. So a longer duration blowing dust episode can be expected, but possibly not seeing the near zero visibility impacts like what comes with a Haboob situation. Blowing dust will be most likely near recently worked fields. A blowing dust advisory may be needed at some point, but confidence is still too low at this time. /SVH Monday through Friday: Near-seasonable temps are anticipated to persist through the extended portion of the 7-day forecast, with daily highs generally within 5 degrees of average. A weak wave may pass by to our north for Tuesday/Wednesday resulting in another increase in winds, but it's not expected to be as windy as Sunday. Frost/freezing conditions are possible next Monday onward as well in our northern sheltered valleys, as is fairly typical this time of year. /KD && .AVIATION... 06Z TAFS: High confidence for VFR conditions. A weak frontal boundary passing through late Saturday with mainly passing cirrus through 00z. After, 00z, some midlevel clouds near 15k ft AGL will be possible over Central WA. Local east/northeast winds at KCOE and KPUW reach 13kt 15-19Z Saturday, otherwise winds are generally 10kts or less for all terminals. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in VFR conditions. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 46 84 51 67 35 65 / 0 0 0 0 0 0 Coeur d'Alene 45 82 51 65 36 63 / 0 0 0 10 0 0 Pullman 49 83 49 62 34 61 / 0 0 0 0 0 0 Lewiston 54 90 56 72 42 68 / 0 0 0 0 0 0 Colville 39 79 40 66 34 64 / 0 0 10 10 10 0 Sandpoint 40 78 48 65 33 62 / 0 0 0 20 10 0 Kellogg 47 83 52 61 35 59 / 0 0 0 10 0 0 Moses Lake 44 80 47 68 37 66 / 0 0 0 0 0 0 Wenatchee 48 77 51 65 41 65 / 0 0 0 0 0 0 Omak 45 78 47 67 38 68 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$