Winchester, ID 83555 Weather

Key messages

- Valley rain and mountain snow showers through the week.

- Periods of light snow showers on the Cascade passes with minimal accumulations.

- Saturday is looking dry for Central Washington. Light rain chances increase over Idaho and Eastern Washington Saturday evening and night.

Synopsis

Low pressure will remain off the coast through Friday then eject inland over the weekend. Valley rain and mountain snow is forecast at times through the week with periods of light snow impacting the Cascade passes. The incoming system will bring increasing chances for light rain Saturday evening and night across Idaho and eastern third of Washington.

Discussion

Thursday through Sunday: A cool and unsettled pattern will continue the next few days as troughing lingers off the Pacific coast. Despite deep troughing, it will start to fill in, limiting the amount of precipitation that will fall. Showers will be limited to the northern mountains and Cascades with light snow above 2500-3000 feet. Accumulations in these areas will be minor, ranging from a dusting to an inch. Deepening SW flow Saturday and Sunday will bring plentiful cloud cover and chances for rain and high mountain snow, primarily to the eastern third of WA and north ID.

The forecast for Saturday evening looks potentially soggy, mostly east of Ritzville, with a 2050% chance of rain. The greatest probabilities will be in southeastern Washington and the southern Idaho Panhandle. Evening temperatures will fall into the low to mid 40s, accompanied by light northeast winds around 1-4 mph. The chance of seeing 0.25 inches or more of rain from 4 AM Saturday to 4 AM Monday is less than 10% west of Ritzville, 10-20% for eastern Washington and northern Idaho north of I-90, and 20-60% for areas south of I-90.

Monday through Thursday: Early next week will start off mostly dry, with high confidence in high pressure building into the region. A weak wave moving through northern BC and Alberta will bring a slight chance of sprinkles near the Canadian border on Tuesday. I am monitoring the potential for air stagnation in this pattern, as models indicate shallow boundary layers with light winds. By Tuesday, temperatures will climb 2 to 7 degrees above normal, reaching the 50s, and will remain there through at least Thursday. /DB

Aviation

12Z TAFS: VFR conditions expected through the 24-hour period for KEAT, KLWS, and PUW. Satellite reveals a blanket of fog and low stratus currently sitting across Northeast WA and North ID. These low ceilings have been gradually expanding southeastward over the Spokane/Coeur d'Alene area and West Plains through the night and will continue to do so through the morning. MVFR ceilings have already reached KGEG, KSFF, and KCOE. There is a 20 percent chance of MVFR ceilings reaching KMWH by 15Z. KGEG, KSFF, and KCOE have a 30-50 percent chance for MVFR ceilings persisting through 19Z.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in VFR conditions for KEAT and KLWS. Moderate confidence in VFR conditions for KPUW. Moderate confidence in MVFR ceilings continuing through 19Z for KGEG, KSFF, and KCOE. Low confidence in MVFR ceilings developing for KMWH.

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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 50 36 52 33 51 34 / 0 0 0 0 30 40 Coeur d'Alene 50 34 52 33 52 36 / 10 0 0 10 20 40 Pullman 52 36 51 32 52 32 / 10 0 0 10 30 60 Lewiston 56 39 55 37 54 40 / 10 0 0 10 30 70 Colville 48 34 51 27 52 24 / 30 0 10 0 20 40 Sandpoint 47 34 48 30 51 32 / 30 0 0 0 10 40 Kellogg 48 33 51 33 53 36 / 10 0 0 10 20 50 Moses Lake 53 36 52 28 53 29 / 0 0 30 0 10 10 Wenatchee 47 37 48 34 49 35 / 0 20 50 0 10 10 Omak 48 36 49 31 49 32 / 20 10 20 0 20 20

Watches, warnings and advisories

WA: None. ID: None.