textproduct: Fairbanks

SYNOPSIS

Gusty winds on the Arctic coast will continue for at least the next couple days. Blowing snow and fog will combine to significantly reduce visibilities on the Eastern Arctic Coast. South of the Brooks Range, more benign weather with warm and dry conditions is expected, with highs in the 50s in most of the Western and Central Interior and in the 60s in most of the Eastern Interior valleys. Generally dry conditions will prevail on the North Slope, while showery conditions will be possible in the Southern Interior beginning this evening and lasting into the weekend, with cooler conditions settling in. These cooler conditions will last Thursday and Friday ahead of another warmup Saturday.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Easterly winds up of 15 to 25 mph will be possible over higher terrain of the Central and Northeastern Interior and could last into Thursday night before weakening.

- Much warmer temperatures are expected the next few days, with highs today rising into mid to upper 60s in the Middle and Upper Tanana Valleys today, with upper 60s to low 70s possible in the far eastern Interior. - It will be mainly dry for the next couple of days; however, some scattered showers will be possible near the Alaska Range slopes and across the Upper Tanana Valley today and Thursday.

West Coast and Western Interior...

- Scattered thunderstorms will be possible from the Upper Kuskokwim Valley into parts of the Western Interior this afternoon.

- Gusty north winds of 25 to 35 mph will be possible today along the western Seward Penninsula and throughout the Bering Strait.

- Warming temperatures are expected the next few days, with highs will rising into the mid to upper 50s across the Western Interior and the Interior Seward Peninsula.

North Slope and Brooks Range...

- Gusty winds will continue across the North Slope today. Winds will be strongest along the Eastern Arctic Coast where winds could peak upwards of 40 mph and are producing blowing snow. There are also areas of fog in the area which will reduce visibility in spots.

- Winds will remain elevated along the coast through at least Wednesday before gradually ending from west to east through the Friday. These winds will lead to areas of blowing snow which could reduce visibility at times.

FORECAST ANALYSIS AND DISCUSSION

A 1026 mb surface high persists across the Arctic north of the Beaufort Sea and is supporting continuing east to northeast winds across the Arctic Coast. Moving into this afternoon, the pressure gradient across the Arctic Coast will strengthen again as it did yesterday, supporting winds gusting to 30 to 40 mph, especially across the Eastern Arctic Coast. General troughing aloft collocated with surface low pressure occupies the southeastern Bering Sea and is helping to bring light rain shows to parts of the YK Delta and Norton Sound areas. Easterly to northeasterly winds, at times gusty, continue in the Eastern/Northeastern Interior, mostly near and north of the White Mountains and especially in the higher terrain. A strongly amplified ridge extends well to the north across western North America, with the northern edge reaching into Eastern Alaska. This ridge will be associated with 850 mb temperatures in the Eastern Interior in the 3 to 7C range today. This warm air will support highs in Eastern Interior valleys in the mid to upper 60s (perhaps lower 70s near the Canadian border) on this afternoon and evening. In the Western Interior, highs in the mid 50s to low 60s will be possible. Lows will generally be in the upper 30s to mid 40s in most of the Interior save the high elevations and the Yukon Flats. During the mid to late week time frame, temperatures could likewise rise on the North Slope, with highs in the mid 20s to low 30s and lows in the teens. Beginning this evening and running into the late week time frame, as flow aloft turns to the southeast, occasional showers will be possible in the Southern Interior, with a slight chance for thunderstorms. Temperatures will cool slightly Thursday and Friday, although warmer temperatures will be possible again this weekend, when highs could rise back into the 50s and 60s south of the Brooks Range.

FIRE WEATHER

Overall troughing continues over the southern Bering Sea as weak ridging persists over southeast Alaska. Over the next couple of days, the troughing out west will slowly move into the Gulf of Alaska, pushing the ridging over southeast Alaska further east into the Canadian Yukon by Thursday. This will allow for strong southeasterly flow to set up over much of the state into the weekend. Precipitation chances will remain low through Wednesday with the development of a few scattered showers possible Thursday afternoon, especially across the Upper Tanana Valley and Lower and Middle Yukon Valleys where a non-zero chance for lightning is possible. Winds throughout the Interior are expected to remain fairly marginal going into the weekend with the exception of brief periods of stronger and gustier winds during the afternoon hours, mainly across higher terrains and the White Mountains. An overall warming and drying trend will continue into the weekend with highs briefly cooling into the mid 50s Thursday and Friday as a weak closed off low in the Eastern Brooks Range pulls in cooler air down south. Otherwise, expect temperatures in the low to mid 60s and min RH values in the 30 to 40% range going into next week.

HYDROLOGY

Koyukuk River: As of Tuesday evening, an ice jam on the Koyukuk River, 9 miles downstream of Hughes, remains in place with flooding continuing in Hughes. Little change in the jam or water levels was observed on Tuesday. A Flood Warning is in effect for the Koyukuk River at Hughes for this flooding. Members of the public and emergency manager reported continued flooding in low lying areas, including impacts to the airport, residences, and school property.

Yukon River: As of early Wednesday morning, flooding was occurring at Stevens Village. It was reported that water levels had risen by 5 feet since midnight. While no homes were being inundated, water levels are expected to continue rising. Given the rapid rise in water levels, this flooding is likely being caused by an ice jam. Impounding water due to the ice jam will cause rapid river rises upstream.

An ice jam at the Yukon River breakup front, about 20 miles downstream of Ruby at the mouth of the Yuki River, has caused water levels to rise upstream in Ruby and the Big Eddy area, with minor flooding occurring in the Big Eddy area as of Tuesday evening. A Flood Advisory has been issued for this flooding.

A long run of bank-to-bank ice was observed nearly 100 miles upstream of the breakup front and likely extended further beyond the view of the River Watch team. The river was reported to be mostly open between Tanana and Galena, although an ice run was seen moving through near Rampart Tuesday evening.

In Galena, the ice sheet in front of new town shifted downstream some Tuesday morning, although intact ice remains in place above and below Galena, including at the entrance of Bishop Rock. Below Bishop Rock, the river had a stretch of open water with degraded in place ice below to Koyukuk. A FLood Watch has been issued for Galena for the potential for ice jam flooding from an ice jam downstream, including near Bishop Rock.

Porcupine River: Water levels in the Porcupine River are rising due to snowmelt which is pushing water into the Sucker River near Ft. Yukon. The Sucker River is starting to flow over low lying roads near the NE end of the runway. Water levels could keep rising for several days as the snowmelt pulse in the Porcupine makes its way into the Yukon River. Residents of Ft. Yukon should monitor water levels through the end of the week. A Flood Watch has been issued for potential snowmelt flooding for the Fort Yukon area.

Chena River: The Chena River has begun to respond to warmer temperatures with increased snowmelt leading to rivers running higher and gages getting closer or reaching action stage.

Salcha River: The Salcha River is expected to reach action stage later this week as warmer temperatures lead to increased snowmelt.

Additional Information: Visit www.weather.gov/aprfc for the latest hydro information.

Please report observed flooding to local emergency services, law enforcement, or to the National Weather Service when you can do so safely.

EXTENDED FORECAST DAYS 4-7

At the start of the extended forecast period, the pattern is dominated by an upper level high over the Arctic Ocean and a very large region of upper level low pressure across the southern Bering Sea and Gulf of Alaska. The upper level features slowly weaken through the weekend causing the pattern early next week to be less certain. Most of the forecast variance remains south of the region, but the weakening upper level features allows for a wider range of possible solutions to develop. Saturday into Sunday another low approaches the Alaska Peninsula, but there is still uncertainty in exactly how far north the low gets. Further north solutions would favor stronger winds across the region and more widespread showery conditions. A more southerly solution would favor weather more similar to this week with relatively mild conditions across Northern Alaska.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Flood Watch for AKZ829-833. PK...Heavy Freezing Spray Warning for PKZ812. Small Craft Advisory for PKZ812. Brisk Wind Advisory for PKZ813-815-860-861. Gale Warning for PKZ814. Brisk Wind Advisory for PKZ858. Brisk Wind Advisory for PKZ859.