Marine Weather and Tide Forecast for Skykomish, WA

SYNOPSIS
Dry, warm conditions through Tuesday. Unsettled weather returns Tuesday afternoon into Wednesday next week with potential for moderate rains, thunderstorms, and gusty winds.

DISCUSSION
Today through Tuesday morning: A ridge centered over the state of Washington will bring drying and warming conditions with little to no impacts through Tuesday morning. High temperatures will peak today, with many places reaching the mid-70s and isolated low 80s.
Low temperatures will be in the high 40s to the low 50s.

Tuesday through Thursday: As a low pressure system nears the PNW coast and moves inland over the California/Oregon border, more active weather will move through the area. In particular, by midday Tuesday PoPs will have increased across much of the forecast area.
The current path of the low has it clipping the eastern third of Washington and the Idaho Panhandle, confining the heaviest precipitation to this area. The majority of the forecast area will see at least a wetting rain (0.10 inches) by Wednesday evening.
Wednesday morning through Thursday morning, much of the Idaho Panhandle and southeast Washington see 0.5 inches of rain. Isolated higher rainfall totals nearing 0.75-1 inch of rain are possible in the WA/ID Palouse and in the foothills of the Central ID Panhandle.
This will lead to rises on rivers and streams, and possible nuisance flooding in poor drainage areas. In particular, Kootenai River at Bonners Ferry is forecast to go into Action Stage by early Thursday morning. Stehekin River is seeing ongoing hydrologic issues, and is expected to reach Minor Flood Stage by Monday. It's worth noting that model spread with precipitation totals is very high. The spread between the 75th and 25th percentile precipitation totals for Wednesday is 0.5-0.8 inches, which indicates disagreement in the track of the low. Should the low track further southeast, lower rainfall totals will be observed. Conversely, should the low track further northwest, higher rainfall totals will be observed. Stay tuned for any forecast updates.

Aside from the rain, there are a few other characteristics of this weather pattern that will result in impacts across the area. Snow levels with this system will be very high, starting at 8000 feet and lowering to 4500-5000 feet by Thursday. Much of this snow will be above pass level. Lookout Pass does have a chance of an inch or so of snow through Wednesday through Thursday. Bottom line: expect little to no wintry travel impacts along mountain passes. Chances for thunderstorms increase, particularly on Tuesday night into early Wednesday morning as temperatures will still be warm ahead of an incoming cold frontal passage. CAPE values are modest on Tuesday night, with 300-500 J/kg expected through Tuesday evening. Main risks with these thunderstorms will be gusty outflow winds and small hail. With the frontal passage, winds will increase Wednesday afternoon, especially across the Cascades, Okanogan Valley and Highlands, Waterville Plateau, Moses Lake, Basin, and northern Blues areas, with gusts 20-25 mph expected and locally higher wind gusts near 35-40 mph. Additionally, high temperatures will drop considerably, nearly 15-20 degrees, from Tuesday to Wednesday. Low temperatures will not see quite as dramatic a drop, though it will still be noticeable at 10-15 degrees.

Friday through Sunday: By Friday, the low pressure system will have moved out of the area and heights will have increased due to a ridge off the coast of Canada. This is where clusters and long term models diverge. There is little agreement in how far the higher heights move inland. However, even with this disagreement, there will overall be a warming and drying trend through next weekend with the departure of the low. /AS

AVIATION
06Z TAFS: An upper-level ridge is currently over the Pacific Northwest. This will result in VFR conditions and generally light winds, and passing high level clouds through the forecast period.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions.

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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 75 47 73 46 53 39 / 0 0 10 50 80 50 Coeur d'Alene 75 47 74 46 53 38 / 0 0 0 50 90 70 Pullman 74 47 69 43 48 38 / 0 0 10 70 90 70 Lewiston 78 51 75 49 54 42 / 0 0 10 70 90 70 Colville 78 45 79 47 64 40 / 0 0 10 50 60 40 Sandpoint 73 46 74 47 54 39 / 0 0 10 50 90 80 Kellogg 74 49 75 46 51 39 / 0 0 10 50 100 90 Moses Lake 80 49 77 50 65 43 / 0 0 10 40 50 20 Wenatchee 77 53 75 52 63 46 / 0 10 10 30 30 10 Omak 78 50 78 51 69 42 / 0 0 10 20 30 10

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