Marine Weather and Tide Forecast for St. Michael, AK

KEY WEATHER MESSAGES
Central and Eastern Interior...
- Mostly quiet weather today, light snow is sitting in the Koyukuk Valley but there is little concern with that.

- Moderate snow is expected in the Eastern AK Range south of Trims Camp through tomorrow afternoon with another 4 to 8 inches of snow expected.

- More impactful weather arrives on Sunday as a front pushes snow, heavy at times to much of the Interior. The snow has a 40% chance to mix with rain Sunday evening into early Monday morning in the Middle Tanana Valley as temperatures rise near and above freezing.
* Any rain changes back to snow on Monday resulting in a slushy mess of accumulations in the valleys. The higher terrain above 1000ft will likely remain all snow throughout the event.
* Snowfall totals will range between 2 and 4 inches in the valleys with between 3 and 7 inches in the terrain around Fairbanks.
* One important note is, if there is rain, it can lead to flooding or pooling/ponding of water since the ground is still frozen, leaving nowhere for the water to drain.

- Any wet/slushy spots will likely refreeze Monday morning and especially Tuesday morning as temperatures drop below freezing.

West Coast and Western Interior...
- A front will bring very strong wind to most of the West Coast with the strongest wind being in the Bering Strait. (Northeast gusts up to 65 mph).

- This same front also provides snow beginning Saturday morning in the Yukon Delta and gradually traversing north and east through Saturday night and Sunday.
* Rain will likely mix with the snow in the Upper Yukon and Lower Kuskokwim Valleys from Mountain Village to McGrath with the best chances being Sunday afternoon through Monday morning.
* Prior to the rain, snow amounts will be around 4 to 7 inches.
North of the mixing line, snow amounts will range between 5 to 10 inches from Ruby to Kaltag (highest in Kaltag) and 3 to 6 inches in the Kobuk Valley.

- Any rain across the area will change back to light snow and snow showers Monday afternoon which will linger into Tuesday.

- Winds will also gradually weaken on Monday and Tuesday. Another system looks to move into the area on Wednesday.

North Slope and Brooks Range..
- Generally quiet weather on the North Slope with unseasonably cold temperatures continuing into next week.

- Light snow will be around the Central Brooks Range tonight and tomorrow with only light accumulations around 1 to 2 inches expected.
* Another area of snow arrives on Sunday, particularly late in the day and gradually traverses north to the coast Sunday night and Monday.
* This second round of snow will bring another 1 to 3 inches in the North-Central Brooks Range with around 1 inch on the North Slope.

FORECAST ANALYSIS AND DISCUSSION
If you couldn't tell by now, the main story is a low in the Bering which is bringing snow, wind and rain to Northern Alaska. But we'll start by looking at 500mb and today we are beginning to see the cold, 510 decameter arctic trough north of Deadhorse dropping south. Weak ridging over the Eastern Pacific is gradually losing its grip on the Interior and will be replaced by troughing tomorrow. Before we get there, the aforementioned low in the Bering is currently positioned over the western Aleutians and will gradually trail a ridge which is moving east over Atka and Nikolski.

As we head into tomorrow morning, the ridge will be over the AK Peninsula and Bristol Bay, but the warm front from the low will be taking over and bringing precipitation. By Saturday afternoon, we will notice the upper trough draped over the Seward Peninsula and North Slope. This will help drop temperatures and provide cold air advection to Western Alaska. To the northwest of this trough is a 543 decameter ridge over northern Siberia, and remember, a 500 decameter low is moving towards the area from the southwest. All of this combined will result in very strong northeast winds, up to 65 mph in the Bering Strait by Saturday evening. The Interior during this time is drying out thanks to some drier air from the arctic trough.

Heading into Sunday, this is the big day for the heaviest snow, rain and strong winds. An abundance of moisture will be launched from the Bering Sea northeast into the Interior. Numerous areas are currently under winter weather hazards which have much more detail for specific locations. The gist of it is, warm, moist air will be overriding cold air from the trough allowing for plenty of instability along with the already potent frontogenesis from the warm front. This results in a wide swath of precipitation from the West Coast to the Interior. The heaviest snow will reside in the higher terrain above 1000ft. This includes the Eastern Alaska Range south of Trims Camp where snow may be measured in feet, especially away from the road.

Heading into Monday, we will be dealing with the effects of snow and rain which may result in localized areas of flooding, or pooling and ponding of water, especially in low-lying areas and typical "poor-drainage" locations. By Monday night, a cold front will push through and many locations with wet/slushy spots will likely freeze and this will make travel very difficult.
Unfortunately we are not out of the woods after this event as there is another right on its heals for Wednesday.

.EXTENDED FORECAST DAYS 4-7...
As mentioned before, there is another low on its way heading into Wednesday. This may be nearly a repeat of the current system with areas of heavy rain, snow and gusty winds. This low does look warmer however, and comes with a longer fetch of moisture from 35N latitude. Nonetheless, we will likely be looking at another round of impactful weather by the middle of next week. This active pattern looks to continue through the end of the week and perhaps next weekend as well.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES
AK...Winter Weather Advisory for AKZ850.
PK...Brisk Wind Advisory for PKZ806-807-810-817-854-856.
Brisk Wind Advisory for PKZ811-857.
Heavy Freezing Spray Warning for PKZ816.
Small Craft Advisory for PKZ816.
Brisk Wind Advisory for PKZ851.