491 FXAK69 PAFG 050007 AFDAFG Northern Alaska Forecast Discussion National Weather Service Fairbanks AK 400 PM AKDT Thu Nov 4 2021 .SYNOPSIS... An upper level short-wave trough and associated surface low are exiting eastward across the Canadian Arctic. Areas of snow and blowing snow persist today along the Eastern Arctic Coast, with visibilities briefly as low as 1/2 mile on Barter Island. Northwesterly winds, which reached 40 to 50 mph, are rapidly diminishing this afternoon with exit of the low. Much of northern Alaska is quiet under the influence of a strong upper level ridge extending from western Canada up to the North Slope. There is a mix of clouds, with high clouds streaming northward up the west side of the ridge mixed in with areas of stratus and fog. Meanwhile tight pressure gradients between a low over Bristol Bay and a strong high over eastern Russia and the Chuckchi Sea are producing gusty northerly winds through the Bering Strait and Northern Bering Sea. Snow showers along the West Coast are also leading to localized areas of snow and blowing snow. && .DISCUSSION... Models...Model spread remains limited in the short range and into the weekend, but increases by the beginning of next week. Aloft at 500 mb a broad trough with axis along the West Coast of Alaska and stretching from the Yukon into Eastern Siberia is anchored by a 486 dam low near 80N and the Dateline and a secondary 510 dam low over the northwestern Gulf of Alaska. An upper level ridge continues to build north into the Central and Eastern Interior and has contributed to trapping dense fog in many valley locations as skies aloft clear and winds diminish. Very little change is expected for the weather pattern other than the upper level trough and colder air aloft drifting to the east over the next several days. 850 mb temperatures over Fairbanks currently near zero Celsius will drop to around 8 below on Saturday morning and drop to around 10 below Sunday and Monday and drop further to around 15 below by Tuesday as colder air moves in from the west initially and then pushes southwest into eastern Alaska from the Canadian High Arctic. Temperatures will slowly drop over Northern Alaska to near normal for most areas by the end of the weekend and will likely drop below normal by early next week. Surface...A broad area of low pressure remains over Northern Alaska with low pressure centers over Bristol Bay and just west of Banks Island. The pressure gradient between the low in Bristol Bay and a high pressure ridge over Eastern Siberia will continue to produce gusty north winds in the Southern Chukchi Sea, Kotzebue Sound, the Bering Strait and the northern Bering Sea into Friday and northwest winds in the same areas into Saturday. High pressure aloft and abundant moisture in the lowest levels of the atmosphere and combined with light winds has produce areas of dense fog over the Central and Eastern Interior. A weak low pressure system breaks away from the low in Bristol Bay and traverses south to north over the Western Interior and pushes north to near Point Hope by Friday evening and will bring another round of clouds and light snow or flurries to the West Coast, the Western Interior, and the Northwest Coast on Friday. A weak front rotating around a weak low in the Gulf of Alaska into the Eastern and Central Interior on Saturday will bring clouds and a chance of light snow to theses areas on Saturday. Temperatures will slowly drop over Northern Alaska through the weekend and into early next week with high temperatures in the Interior dropping from the upper 20s and lower 30s this afternoon into the lower 20s by Sunday and into the lower teens to single digits above by the middle of next week. Low temperatures in the Interior will drop from the teens tonight to the single digits above and below zero by early next week and will continue into late next week. The upper level airmass would support surface low temperatures in the teens below in the coldest locations should a particular location receive several hours of clear skies late next week. Coastal Hazard Potential Days 3 and 4...None. && .AFG WATCHES/WARNINGS/ADVISORIES... Heavy Freezing Spray Warning for PKZ210-PKZ225-PKZ230-PKZ235-PKZ500. Small Craft Advisory for PKZ210-PKZ220-PKZ225-PKZ230. Brisk Wind Advisory for PKZ245. && $$ AFC NOV 21