Marine Weather and Tide Forecast for Oakesdale, WA

DISCUSSION

Tonight through Wednesday night: Strong ridging of high pressure over the northwest will divert moisture off of the eastern Pacific well into BC. Some moisture aloft will spread across the region in the form of high cirrus cover. The subsidence inversion under the ridge will continue to trap moisture in the boundary layer with a mixture of fog and low stratus cover. Winds in the boundary layer will tend to push moisture into the northern mountain valleys and into the valleys of the east slopes of the Cascades.

Thursday through Friday: A shortwave trough of lower pressure will push across western Canada topping over the ridge in place. The bulk of the dynamics and moisture will remain in Canada with the frontal passage on Thursday. Light snow up to an inch will be possible over the Cascade crest and over the northern mountains, especially near the Canadian border. Otherwise, this will be a dry cold front passage. Drier air with the front looks to scour out the low clouds in the lee of the Cascades with moisture sloshing back towards southeast Washington and into the southern to central Idaho Panhandle by Thursday evening. The western edge of the upper level trough will extend out into extreme eastern Washington with temperatures at 500 mb dropping down to between -30 to -35 degrees Celsius. This will destabilize mid levels of the atmosphere with the potential for some convective showers to form.
There will be very limited amount of moisture to work with though for precipitation to form, and I don't expect much more than isolated snow showers.

Friday night through Tuesday: The ridge of high pressure amplifies and retrogrades a bit over the weekend into early next week. An Arctic air mass will encompass the Plains. Only a small fraction of that modified Arctic air will be able to push through the Great Divide into the Inland Northwest. It will have the effect of bring our coldest temperatures of the winter. Low temperatures look to drop into the single digits for the deeper mountain valleys and into the teens over the basin. High temperatures will only warm into the 20s. How cold temperatures get will be highly dependent on cloud cover. /SVH

AVIATION
00Z TAFS: Low stratus has burned off from near TAF sites, but is expected to return tonight with the addition of fog again. Exact location of the fog and low ceilings remains uncertain but based on todays conditions, similar to what was seen for the first half of the day. KPUW-KLWS remains outside the threat of low ceilings and will see partly cloudy skies overnight.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Low confidence where fog will form from KGEG to KCOE. High confidence in IFR conditions returning tonight.

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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

PRELIMINARY POINT TEMPS/POPS
Spokane 26 36 26 36 22 31 / 0 0 0 0 0 0 Coeur d'Alene 24 39 25 37 21 31 / 0 0 0 0 0 0 Pullman 27 40 28 42 24 31 / 0 0 0 0 10 10 Lewiston 31 44 32 48 31 38 / 0 0 0 0 10 10 Colville 22 35 22 33 16 30 / 0 0 0 10 0 0 Sandpoint 26 37 26 35 24 30 / 0 0 0 10 10 10 Kellogg 26 41 27 40 22 30 / 0 0 0 0 10 20 Moses Lake 28 39 26 37 24 38 / 0 0 0 0 0 0 Wenatchee 26 36 29 39 26 38 / 0 0 0 0 0 0 Omak 25 34 26 36 20 34 / 0 0 0 0 0 0

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