textproduct: Fairbanks

SYNOPSIS

Generally quiet weather persists in Northern Alaska with ongoing troughing expected to remain the dominant feature through Saturday. An upper low in SW Alaska will provide showers and areas of rain to Western AK through Friday with another low taking its place this weekend, prolonging the wet pattern out west. Expect a few showers to exit the Central/Eastern Interior today with more wet weather returning to the Northern Interior and Brooks Range Friday afternoon. With the low mainly situated over Western AK, a ridge will try to build over Western Canada providing southerly flow and drier weather to the Central/Eastern Interior, particularly south of the White Mountains this weekend. This pattern will also result in periods of AK Range gap winds around 40 mph with stronger winds, potentially up to 60 mph this weekend.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Drying weather today with cool temperatures, in the 60s to near 70. A few showers in the S. Interior Friday, more widespread showers Friday PM north of the White Mtns. Generally drier weather overall after Friday and into the weekend.

- A slight chance for a thunderstorm Friday afternoon and evening across the Interior.

- Weak chinooking develops tonight with south winds upwards of 45 mph in the AK Range passes. Winds persist through Saturday and may strengthen Saturday afternoon into Sunday.

- A warming trend arrives on Sunday and into next week with a ridge briefly building in to the east.

West Coast and Western Interior... - Continued wet and cool weather is expected over Western Alaska through the weekend as scattered to numerous showers persist.

- Rainfall totals through Sunday afternoon will be around 0.10" to 0.25" along the coast, 0.25" to 0.50" in the Interior and 0.50"+ in the southern slopes of the Western Brooks Range.

- Temperatures will be on a slight warming trend into the low to mid 60s this weekend.

North Slope and Brooks Range.. - Areas of stratus clouds and fog most likely during the evenings and overnight along the coast with partial clearing during the day as weak surface onshore flow persists.

- Persistent southerly flow aloft will result in downsloping on the North Slope which will battle any stratus and fog that develops.

- Periods of rain for the Brooks Range this afternoon through Saturday afternoon with a drying trend Saturday night. Rainfall amounts around 0.25" to 1.00" with the highest amounts on the south side of the Range.

FORECAST ANALYSIS AND DISCUSSION

A messy pattern is in store with troughing spreading over Northern Alaska. We will see areas of showers, periods of rain, isolated chances for storms and cool temperatures through the weekend. Most of the rain is going to be in Western Alaska, and southern slopes of the Brooks/Alaska Ranges due to southerly flow. The Interior remains drier, but not completely dry as a series of fronts brings enough forcing for showers and even an isolated thunderstorm.

Getting into the specifics a bit more, there is an upper low in the northern Yukon providing rain to the AlCan Border and Eastern Brooks Range. This low will move northeast, drying out that area tonight. Out towards the west, there is an upper low over Bristol Bay which is moving northeast and will provide rain to Western Alaska through tomorrow. As this moves northeast, its associated front moves from south to north over the Interior and brings showers/periods of rain. In the Central Interior, there is a chance for showers in the morning, then more widespread rain moves north towards the southern Brooks Range. An isolated thunderstorm is also possible Friday afternoon/evening with a secondary front approaching. This front will come with cold air advection aloft and run into some moisture pooling in the Interior valleys which can spark a couple of thunderstorms. One last thing this low will do is increase southerly chinook flow north of the AK Range. South winds in the AK Rang Passes will gust upwards of 45 mph on Friday.

Out west, expect persistent showers through the weekend with embedded periods of rain possible. Up north, the North Slope will remain mostly dry through Friday, then a front brings rain from the Brooks Range northward to the coast on Saturday. The heaviest rain lies in the Brooks Range as it continues to lose moisture northward. There are also chances for thunderstorms on the south side of the Brooks Range.

Otherwise, another low moves into SW AK on Sunday with a round of rain and showers, keeping the wet trend going across Western Alaska. This low will bring more chinook flow to the Interior with strong gap winds, warmer temperatures and much drier conditions.

FIRE WEATHER

The driest area of the Interior is the Upper Tanana Valley where FFMC's remain in the 80s to near 90. Min RHs will drop to near 30% today with light winds.

Fuels remain wet elsewhere with very little burnable fuels. We are expecting continued wet weather across Western AK with showers in the Interior. Isolated thunderstorms are expected in the Brooks Range today, with a spread into the Interior tomorrow. Otherwise, chinook flow increases tomorrow and especially this weekend with southerly gap winds around 45 mph on Friday, then upwards of 50 to 60 mph possible this weekend. A ridge begins to build in on Sunday keeping it relatively mild over the Central/Eastern Interior, then troughing takes over once again towards the middle of the week with increased chances for rain.

HYDROLOGY

No concerns at this point, but consistent rain over the southern slopes of the AK Range as well as in Western Alaska will keep the rivers running high but there is no concern for flooding.

EXTENDED FORECAST DAYS 4-7

A highly amplified pattern will start the period as a longwave trough remains anchored over the West Coast and the Bering Sea while strong ridging builds into northwestern Canada and the Eastern Interior. This setup will sustain a tight pressure gradient and strong southerly flow across the state, generating gusty gap winds through the Alaska Range passes that are expected to persist from Sunday into Tuesday. Under the influence of the ridging pattern, a warming trend will bring widespread highs in the 70s to lower 80s across much of the Interior and southern North Slope through Monday, accompanied by drying conditions that will push afternoon minimum relative humidity values down into the upper 20s and low 30s. Conversely, extensive and persistent rain showers will remain locked over Western Alaska beneath the trough on Sunday and Monday. By Tuesday and Wednesday, the warm and dry spell across the Interior is expected to break as the western trough shifts eastward, pushing a cold front and another round of widespread rain into the Central and Eastern Interior.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Small Craft Advisory for PKZ811-812-857-858.