Marine Weather and Tide Forecast for Sandpoint, ID

SYNOPSIS
Chances for showers and afternoon thunderstorms continue through Sunday. Areas of moderate rain will develop Sunday night and continue into Monday for the Idaho Panhandle and southeastern WA. A cold front passage Tuesday afternoon into Wednesday will bring additional light rain in the lowlands, mountain snow, and breezy to windy conditions.

DISCUSSION
Today through Monday: The northern reaches of a strong mid-level wave are beginning to arrive in Southeast Washington and the Central Panhandle Mountains this afternoon. This wave is creating enough forcing to trigger convective pop-up showers across the eastern third of Washington and North Idaho with potential for thunderstorms lasting into the evening. We have already seen a few strikes with storms in the far southeastern corner of the region (Nez Perce and Lewis Counties).

More steady rain will move in tonight across Southeast Washington, the Central and Northern Idaho Panhandle, and along the Washington/Idaho border. The highest totals are favored on the Palouse into the LC Valley and Camas Prairie. The rain will lead to rises on small streams, but no flooding is currently expected. Snow levels will remain high, staying around 6000-7000 feet today and lowering to 5000-6000 feet by Monday morning. This will keep snow above the mountain passes and confined to the higher peaks for now. By Monday afternoon, what is left of the deformation band weakens and shifts east with mainly mountain showers expected.

Tuesday through Thursday: A deep low pressure system will send a robust cold front through the Inland NW. Strong westerly flow will lead to a rain shadow across Central WA with only light precip amounts (if any), while the Cascades and ID Panhandle will see a burst of precipitation with a cold front passage.
Snow levels with this system start out between 3000-4500 feet (lowest snow levels in the Cascades) on Tuesday, dropping to 1000-3000 feet behind the front on Wednesday. This system will bring late season snow to the mountains.

Stevens Pass has a 70% chance of seeing more than 8 inches of snow and a 40% chance of more than 12 inches of snow from 5 PM Monday to 5 PM Wednesday.

Lookout Pass has an 80% chance of more than 4 inches and a 40% chance of more than 8 inches from 5 PM Tuesday to 5 PM Thursday.

In addition to mountain snow, this system will also bring gusty winds, with wind gusts of 30-45 MPH across the region Tuesday and Wednesday. Colder air behind the front will drop temperatures, with widespread freezing temperatures expected Wednesday night and Thursday night. Lows will be in the 20s to low 30s.

Friday and Saturday: Dry conditions and clear skies are forecast as the low exits the region and a weak shortwave ridge moves in. Temperatures will warm closer to seasonal normals. /Fewkes

AVIATION
00Z TAFS: Widely scattered showers and thunderstorms will continue into the evening across the eastern third of WA and North ID. KPUW and KLWS have the highest chance of being impacted by these storms, but KGEG- KSFF- KCOE may be impacted as well (20 percent chance). Later tonight, KLWS- KPUW should expect steady rains and lowering CIGS with areas of MVFR conditions. Rains will spread into KGEG-KSFF-KCOE late Monday morning.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is a 15-30 percent chance of thunderstorms mainly south of Spokane/Coeur d'Alene Sunday evening including KPUW/KLWS. As steady rains arrive, ceilings will lower to MVFR.

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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 43 61 37 51 37 48 / 40 50 10 30 90 70 Coeur d'Alene 44 56 38 50 38 47 / 50 70 20 40 100 80 Pullman 42 54 35 51 38 45 / 90 70 10 20 90 90 Lewiston 47 59 39 59 44 51 / 90 70 0 0 90 90 Colville 39 66 36 53 33 51 / 30 60 10 60 90 60 Sandpoint 43 54 36 44 34 44 / 30 90 40 70 100 90 Kellogg 44 50 37 47 37 43 / 70 90 30 60 100 90 Moses Lake 44 66 38 58 37 54 / 20 10 0 10 30 30 Wenatchee 47 61 42 56 37 52 / 10 0 0 20 40 20 Omak 43 63 38 50 31 52 / 10 0 0 30 50 30

OTX WATCHES/WARNINGS/ADVISORIES
WA...None.
ID...None.