textproduct: Fairbanks

SYNOPSIS

Trailing surface front associated with yesterday's system will be moving into Canada. Isolated rain showers over the White Mountains and Fortymile will end this evening. There will continue to be extensive low clouds, fog and some drizzle along the West Coast and the Arctic Coast tonight. On Friday a weak shortwave will spread some scattered light rain and gusty southwest winds over the Lisburne Peninsula up through Utqiagvik. The scattered rain spreads east across the North Slope and the Brooks Range on Saturday. Otherwise A strong high pressure ridge will build over northern Alaska into the weekend. Skies will become mostly clear with a warming and drying trend. Hottest spots will be in the Central and Eastern Interior. Along the Arctic Coast and the West Coast temperatures will remain cooler. More widespread rain and cloud cover is expected to spread into the West Coast and Western Interior on Sunday.

KEY WEATHER MESSAGES

Central and Eastern Interior... -Isolated rain showers will diminish across the the White Mountains and Fortymile this evening.

-Warmer and drier weather into Sunday with highs peaking in the mid 70s to near 80.

-The weather pattern shifts early next week as a southwest flow is projected to spread more clouds and rain up into the Interior.

West Coast and Western Interior... -Areas of low clouds, fog and drizzle will continue over the West Coast into Saturday. More widespread rain is expected throughout western Alaska Sunday into Monday.

-High temperatures will peak in the 70s in the Interior on Saturday with 50s and 60s along the West Coast.

North Slope and Brooks Range.. -Low clouds and fog will continue along the Arctic Coast into Friday.

-Scattered light rain and gusty southwesterly winds 20-30 mph develop Friday across the Lisburne Peninsula up through Utqiagvik. The scattered rain spreads east across the North Slope and the Brooks Range on Saturday.

-Temperatures will peak in the 50s near the coast and 60s on the Arctic Plains.

SHORT TERM FORECAST DISCUSSION

Weak surface front associated with yesterday's short wave trough will move into Canada. Isolated rain showers over the White Mountains and Fortymile will diminish this evening as a high pressure ridge builds over the Interior. Skies will become mostly clear with a warming and drying trend. 850mb temps will increase into the 10-15C range over the Central and Eastern Interior into Sunday. This will allow for high temperatures to warm into the mid 70s to near 80. Meanwhile a longwave trough over the Bering Sea will begin push shortwave energy into the high pressure ridge. Friday a glancing blow occurs up over the Lisburne Peninsula up through Utqiagvik resulting in scattered light rain and gusty southwesterly winds 20-30 mph. A stronger Bering Sea short wave pushes into the ridge Saturday into early Sunday. Scattered rain will spread east across North Slope and Brooks Range, and increase over the West Coast. On Sunday even stronger short wave energy is projected to push the ridge axis east toward the Yukon Territory. A southwest flow develops and begins to spread clouds and more widespread rain into the West Coast and the Western Interior. This eastward translation of the ridge is supported downstream by a low pressure system forming over the Hudson Bay.

FIRE WEATHER

As the Arctic front leaves Alaska, drier weather will begin to settle across the state. Weak ridging begins to build across the West Coast and Western Interior before moving east across the rest of the Interior Friday and Saturday. Today continues the warming trend with highs in the 60s to near 70 across the Interior with min RHs in the 30 to 40% range in the Central/Eastern Interior and 35 to 50% in the Western Interior. High temperatures in the 70s to near 80 are expected to travel with this ridge as it moves across the state, leading to the Western Interior seeing its highest temperatures on Friday, the Central Interior seeing its highest temperatures on Saturday, and the Eastern Interior seeing its highest temperatures on Sunday. Min RHs will likely drop down into the 25 to 35% range as the ridge passes as well. Winds will be on the lower side across most of northern AK through the first half of the weekend and the ridge should suppress thunderstorm development.

As we get into the later weekend and next week, the ridge is pushed east into Canada as a low moves in from the Bering, leading to southwest flow for Alaska. This low is expected to potentially bring quite a bit of precipitation due to moisture from the tropics it's bringing north. Precipitation totals still vary between models and model runs, but do anticipate widespread wetting rains across much of the Western Interior and Kuskokwim Delta Area, with more isolated to scattered showers across the Central and Eastern interior. Models are also hinting at the potential for gusty southerly winds through the Alaska Range passes beginning as early as Monday morning, leading to the Central and Eastern Interior being Chinooked for this event.

HYDROLOGY

No concerns at this time, rivers are near normal stages.

LONG TERM FORECAST DISCUSSION

Monday through Thursday Ensembles have come into agreement on forming a low pressure system over the Bering Sea and moving it to the Yukon Delta region on Monday. Water levels will continue to be monitored for the Yukon Delta coast southward. Current projections show minor 1-2 feet of surge above the highest tide line. The moist, southwest flow that is established on Sunday continues on Monday. Widespread rain will continue to spread from the West Coast farther inland - up into the Brooks Range and across the Western and Central Interior. Much cooler temperatures will occur in those areas. 24 hour greater than or equal to a half inch (0.5") QPF probabilities ending 12Z Tuesday continues to zero in on the Kuskokwim valley and western Alaska Range up into the Koyukok river valley. We coordinated accordingly with WFO AFC and WPC on heavy rain hazards in the 3 to 7 day national outlook.

There is still much uncertainty in the 12Z deterministic mid-range model runs (including the AI versions) on where this low tracks next. Both the GFS and Canadian are keeping the low up over the Norton Sound region resulting in the southwest firehose of moisture continuing Tuesday and Wednesday. The ECMWF drops the low south near the Kuskokwim Delta region. That would keep moisture more over the Western Interior with a southerly Chinook developing over the Alaska Range. It is possible for gap winds to gust to 70 mph through Windy and Isabel pass by late Monday so we will continue to monitor for that threat.

Beyond that the trend seems to be for the low to drop down over Bristol Bay and head south into the Gulf of Alaska on Thursday. This appears to be in response to the next upstream arctic trough approaching from the Chukchi Sea. Widespread rain and gusty winds would occur over the Lisburne Peninsula. The Alaska Range Chinook/gap wind gradient would diminish by this time. Scattered rain showers and thunderstorms would be focused on where west-east oriented short wave energy remains over the northern Interior and Brooks Range.

Coastal Hazard Potential Days 3 and 4... A low pressure system will move from the Bering Sea to near Norton Sound by Monday. Gusty southwest winds 30-40 mph could occur. We will continue to monitor water levels for the Yukon Delta coast southward. Current projections show minor 1-2 feet of surge above the highest tide line Monday.

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Small Craft Advisory for PKZ807. Small Craft Advisory for PKZ810. Small Craft Advisory for PKZ811. Small Craft Advisory for PKZ812. Small Craft Advisory for PKZ856. Small Craft Advisory for PKZ857. Small Craft Advisory for PKZ858.