Spokane, Washington

• Patchy fog overnight.
• Cool temperatures, light winds, and a slight chance (15-30%) for sprinkles or very light rain Saturday evening.
• Rain chances increasing 20-60% late Saturday night into Sunday. Light rain accumulations up to a tenth of an inch expected over Southeast WA and the southern Idaho Panhandle.
• Dry conditions Sunday evening through Wednesday.

Mid and high clouds increase Saturday bringing a small chance of sprinkles and showers to eastern Washington and north Idaho in the evening. Dry air filters in Sunday and conditions remain seasonal and dry through Wednesday.

Saturday and Sunday: The upper low offshore continues to fill in and slide to the south towards the northern California coastline Saturday evening. This will bring weak synoptic ascent into the region Saturday afternoon and evening, bringing small chances for light rain (5-15% chance over central WA, 10-30% chance for eastern WA and north ID). PWATs increase to 110-130% of normal Saturday afternoon and evening but dry air near the surface will only allow for sprinkles to a light drizzle mainly east of Ritzville. Rain amounts will be very light around a trace to a tenth of an inch through Saturday night. Light rain continues into Sunday for southeast WA and the central and southern ID Panhandle ahead of drier air filtering in from the west. Clouds will erode in the late morning and early afternoon Sunday in central and eastern WA and the late afternoon around sunset in north ID. The chances of a tenth of an inch or more of rain from Saturday afternoon to Sunday are around 20-50% south of I-90 and east of US-395.

Monday through Saturday: High pressure builds into the region Monday bringing dry conditions and seasonal temperatures in the upper 40s to mid 50s. This ridge will be slightly disrupted Monday night into Tuesday by a shortwave moving through central BC and AB, bringing a small chance for snow showers in the Cascades above 3500 feet. Impacts look very minimal from this system. The ridge strengthens behind this weak wave Wednesday but chances for precipitation increase Wednesday night as troughing approaches the region. Models are in some disagreement with the position and strength of the placement of this trough but the overall message is there is a signal for unsettled conditions to return mid to late next week. Global ensembles continue to show a 60/40 split towards dry conditions continuing but this will change in the coming days as confidence increases. /DB

18Z TAFS: Saturated profiles and light winds allowed fog to persist at GEG and PUW well past 17Z. GEG has quickly improved to VFR. Ceilings are sticking around longer at PUW and it is currently at LIFR, though high res models show improvement by 20-22Z. LWS is at MVFR for ceilings but did not see fog and is expected to improve to VFR within the next hour or two. A band of rain will move through eastern Washington and N Idaho around 06Z-18Z for GEG, SFF, COE, PUW, and LWS, though PoPs are below 50 percent across all areas for this time period. With highest precipitation amounts southeastward, PUW and LWS will see rain chances from 12-18Z, while chances for GEG, SFF, and COE decrease below 30 percent at 12Z.

Models for tomorrow show overall much lower chances for patchy dense fog, though with how they struggled with this morning`s fog, we`ll be keeping a close eye on model soundings through the day. The one exception is PUW, where models have been consistently indicating that ceilings will drop back down to LIFR by around 12Z.

Winds at GEG, SFF, PUW, and LWS are expected to be light through the period. Only COE is seeing winds above 10kts, and those winds are expected to decrease around 00Z.

At MWH and EAT, VFR conditions are expected through the next 24 hours, with light winds and no precipitation chances.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in ceilings improving to VFR for PUW and LWS within the next couple hours. Moderate confidence in timing of showers moving through. High confidence in VFR conditions through the next 24 hours for MWH and EAT. Moderate confidence in returning low ceilings for PUW starting tomorrow at 12Z. Moderate confidence in ceilings staying VFR for GEG, SFF, COE, and LWS through the TAF period, though there is the potential for returning IFR/LIFR conditions tomorrow morning. Fog and ceiling degradation potential is the most impactful alternate scenario, which would prompt amendments. /AS

Confidence descriptors:Low - Less than a 30 percent chanceModerate - 30 to 70 percent chanceHigh - 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

Spokane        52  37  51  32  51  35 /   0  20   0   0   0   0
Coeur d`Alene  52  37  52  33  52  35 /   0  20  10   0   0   0
Pullman        47  34  48  30  48  33 /   0  40  40   0   0   0
Lewiston       52  42  53  38  53  39 /  10  50  50   0   0   0
Colville       54  27  51  22  51  25 /   0  10  10   0   0   0
Sandpoint      51  33  50  29  50  31 /   0  10  10   0   0   0
Kellogg        51  36  51  33  51  35 /   0  20  20   0   0   0
Moses Lake     55  32  54  26  54  34 /   0   0   0   0   0   0
Wenatchee      54  37  52  34  52  40 /   0   0   0   0   0  10
Omak           54  34  51  29  51  36 /   0  10   0   0   0   0

WA

None.

ID

None.