textproduct: Fairbanks

SYNOPSIS

Much quieter weather across most of Northern Alaska to start the new week as high pressure becomes the dominant weather influence for the next several days. Light snow showers across the West Coast and Western Brooks Range diminish this morning while scattered snow showers remain north of the Brooks range and along the arctic coast through the day. Dry conditions and above average temperature expected for the Interior today and for the next several days with the warmest locations over the western half of the state where highs in the 20s to mid 30s above zero will be common. A few light snow showers possible along the west coast through the week as numerous systems move into the Bering then Siberia, but overall nothing too concerning locally. A stronger system traverses the top of the ridge Friday, bringing a round of snow and wind to the North Slope. This disturbance will kick start a pattern change across the whole state as a much colder arctic airmass moves in from the west/northwest this weekend, pushing the ridge and warmer airmass further west. Temperatures start to drop late this week, with below zero temperatures returning over the weekend, especially for the Eastern and Central Interior.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Weak Tanana Valley Jet developing this afternoon and evening, winds increasing but remaining below advisory criteria for Delta Junction

- Dry with above average highs in the teens to upper 20s

- Cooling trend end of the week into the weekend with temperatures falling back below zero, coldest in eastern Interior.

West Coast and Western Interior...

- Snow showers for the NW Coast and Western Brooks Range diminishing through the day

- Mild with widespread high temperatures in the 20s to low 30s continue for the next several days

- Mainly dry, but a few snow showers possible along south facing slopes Tuesday and Wednesday

North Slope and Brooks Range...

- Light snow persisting for the North Slope today

- Increasing westerly winds with gusts above 35 mph along Arctic coast Tuesday may result in reduced visibility and blowing snow.

- Watching for a stronger system Thursday - Friday to bring widespread snow and wind to North Slope

- Well above average temperatures in +0s to 20s through midweek, then back below zero by the weekend

FORECAST ANALYSIS AND DISCUSSION

A stretch of much quieter weather is on the way for much of Northern Alaska through the week as high pressure and ridging will be the dominant weather influences locally. Satellite imagery early Monday morning shows high pressure over the interior with widespread low stratus and fog in lower valleys, especially in areas that received snowfall over the past day or so. Expect a clearing trend later today; however more wind sheltered valleys may be stuck under low clouds through this evening. Otherwise, generally quiet weather as high pressure keeps an anomalously warm airmass in place. While 850mb temperatures will be significantly above average for this time of year, strong surface inversions have been keeping many valleys and low lying areas colder than what guidance suggests. Warmer locations may be confined to higher elevations above the surface inversion. Hi-res guidance suggest an increase in the Tanana Valley jet and overall easterly gap flow across the Interior today as a low pressure traverses north in the Bering. Locations prone to easterly gap winds will likely mix out and warm up into the 20s, possibly higher. Currently greatest wind threat looks to be around Delta Junction where sustained winds of 20mph or higher are possible, but should remain below advisory criteria.

The most active part of the state this week looks to be the NW Coast and North Slope as disturbances ride along the top of the ridge. While the main storm track has shifted west, bringing pacific lows northwestward into Siberia, trailing frontal systems may bring isolated to scattered snow showers to south facing slopes today through Wednesday. A low pressure trough develops over the North Slope and Brooks Range on Tuesday while a 1040mb High exists over the high arctic resulting in a 30-35 kt low level easterly jet along the arctic coast and southerly gap winds through the Brooks Range. Depending on how much new snow falls, periods of near blizzard conditions and blowing snow are possible, especially around Kaktovik.

EXTENDED FORECAST DAYS 4-7

High pressure remains in place over the Interior mid to late week; however a pattern change is on the horizon. By the end of the week, longer range guidance has been consistent in showing a strong storm system developing and moving along the top of the ridge in the Chukchi sea and high arctic. This system will have numerous impacts to sensible surface weather and the overall weather pattern. While confidence is lower on the finer details, confidence is increasing that a strong system pushes eastward near the arctic coast Thursday into Friday bringing a period of strong winds, widespread snow, and possibly blizzard conditions to the NW Coast and North Slope...with deteriorating conditions possibly as far south as the Seward Peninsula depending on how the storm system evolves. The rest of the interior remains relatively quiet in the extended with temperatures slowly cooling down toward the weekend.

This system impacts the anomalously strong ridge in place over the week, creating a weakness along the top of the ridge, allowing a deep trough over NW Canada to push westward into the Interior of Alaska ths weekend. High confidence exists in this pattern change by the weekend with a much colder airmass advecting in with 850mb temps back into the -20s once again. The ridge aloft becomes centered over the Bering and Siberia as troughing takes hold of the state. A few day period of temperatures in the 0 to -25 range are likely, especially for the Eastern Interior where the core of the colder air will be. Mild, above average temperatures hold on a few days long along the west coast, before the arctic airmass pushes west. Expect northerly gap winds to significantly increase across much of the state this weekend as strong high pressure sets up over the high arctic behind the late week system.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Heavy Freezing Spray Warning for PKZ804. Brisk Wind Advisory for PKZ812-858. Brisk Wind Advisory for PKZ813-850. Brisk Wind Advisory for PKZ815. Brisk Wind Advisory for PKZ851. Brisk Wind Advisory for PKZ859. Brisk Wind Advisory for PKZ860. Brisk Wind Advisory for PKZ861.