Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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234 FXUS66 KOTX 041809 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1109 AM PDT Sat May 4 2024 .SYNOPSIS... It will be mild today with highs in the 60s and low 70s while bands of rain spread into central Washington. Rain will be widespread on Sunday as a slow moving low moves through the Pacific Northwest. As the low pulls out of the region, look for cool, showery, and brisk conditions Monday and Tuesday. Warmer and drier weather will likely arrive late next week. && .DISCUSSION... Today through Monday afternoon: The start of the weekend will be mild, cloudy, and breezy thanks to a low pressure moving towards northern California. Along with that, rain chances increase in central Washington through the morning into the afternoon hours. Eventually chances for measurable rain spread into Eastern Washington this evening and overnight. Model disagreement is quite high still for the wrap around precipitation band Sunday morning in eastern Washington. There is a 60% chance of greater than 0.10 of an inch of rain from midnight through noon Sunday. 3-7 am Sunday appears the most favorable time for the deformation band to move through Spokane, although some models indicate a light rain lasting through much of the day. Unsurprisingly, ensemble members with less rain warm temperatures up slightly faster during the morning. There is a 75% chance of temperatures not exceeding 45 degrees through noon Sunday. While the rain will be beneficial for dryland farmers in the Palouse and West Plains after a dry April, outdoor activities on Sunday will be dampened by the rain and cooler temperatures. Monday will feature cooler temperatures compared to the norm, accompanied by showers and localized windy conditions. The departing low pressure system from the weekend will set up a tight westerly pressure gradient across the Cascades on Monday, resulting in gusty winds. According to ECMWF ensembles, wind gusts up to 35 mph are anticipated on Monday, with 50-70 percent of ensemble members forecasting gusts of 35 mph or higher across eastern Washington. Monday night through Tuesday night: Brisk and showery. Northwest flow aloft prevails over the Inland NW as the slow moving low tracks into MT and a secondary weaker trough brushes in from the Pacific. Showery precipitation decreases Monday evening while brisk westerly winds persist through the night. A surface trough over eastern WA keeps pressure gradients packed, leading to wind gusts of 35-40 mph are possible in the lee of the Cascades and Palouse. The winds relax slightly Tuesday morning and shift from the west to northwest by the afternoon hours with higher gusts returning again across central WA into the Palouse. Showery conditions redevelop Tuesday afternoon and evening although with less coverage and mainly for extreme eastern WA into north ID. Snow level take a dip during the overnight hours with light snow accumulations in the central Cascades, Blue mountains, and Panhandle mountains. It will on the cool side with daytime temperatures in the 50s to lower 60s and overnight lows in the mid 30s to lower 40s. db Wednesday through Saturday: Drier and warmer. An upper level ridge builds over the eastern Pacific and builds inland. Still can anticipate a threat of showers over north Idaho for Wednesday, but trending less coverage for Thursday as drier and more stable conditions arrive. Winds decrease and shift from the north and east. Under lighter winds, the more noticeable change will be warmer temperatures reaching the 60s to lower 70s on Thursday and in the 70s to lower 80s by Friday into Saturday. /rfox. && .AVIATION... 18Z TAFS: Mid to high level clouds will continue to increase across the Inland NW and gradually lower this afternoon and evening as bands of precipitation move up from the south. Light rain is expected across the Cascades by the morning hours on Saturday with rain at KEAT by 16Z with local MVFR ceilings. South and easterly winds will pick up with the front approaching. Ceilings will continue to lower overnight. Rain bands will increase across KLWS, KPUW, KCOE to KGEG after 05Z. There is a 90% probability of MVFR ceilings for KGEG-KCOE-KPUW after 10Z. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions through Saturday night. Chances for MVFR ceilings expand early Sunday morning to KLWS, KPUW, and KGEG. There is low probability of visibility dropping below 3SM at Taf sites. Ensembles have brief periods of 2SM at KPUW. JDC ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https://www.weather.gov/otx/avndashboard && .PRELIMINARY POINT TEMPS/POPS... Spokane 69 43 50 40 58 36 / 10 40 80 80 40 20 Coeur d`Alene 67 43 50 39 53 36 / 10 30 80 90 70 30 Pullman 66 40 47 38 52 35 / 30 80 80 90 60 40 Lewiston 72 48 56 45 61 41 / 30 90 70 90 60 30 Colville 68 43 52 39 59 34 / 10 10 70 90 70 40 Sandpoint 65 44 50 40 55 38 / 0 20 80 90 80 50 Kellogg 65 46 47 40 49 38 / 10 30 80 100 90 60 Moses Lake 72 47 58 41 62 38 / 20 60 80 30 10 0 Wenatchee 63 50 59 44 59 41 / 60 40 60 20 20 10 Omak 70 49 62 41 62 38 / 30 10 50 30 20 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$