textproduct: Fairbanks

SYNOPSIS

An upcoming pattern change means cooler temperatures are on the way out with periods of widespread showers expected during the transition period this weekend. Winds will strengthen Friday as a pressure gradient tightens across the State. The strongest winds will form along the north and west coasts Saturday evening. Saturday and Sunday, there are chances for some early season thunderstorms in the Southern Interior.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Chances for precipitation become more widespread across the Interior Saturday morning. Precipitation type should be mostly rain, apart from higher elevations where snow or a rain/snow mix could occur.

- Cooler temps expected Friday with maximum temperatures in the mid to upper 40s. Similarly, minimum temperatures will cool into the low 30s, allowing for some patchy areas of frost to develop overnight.

- Gusty NE winds will continue across the Interior Friday, for the south slopes of the Brooks Range and Dalton Hwy Summits, winds could get up to 35 mph Saturday night into Sunday.

- There are chances for thunderstorms in the Southern Interior Saturday and Sunday. On Saturday, chances are best near the AlCan border in the Southeast Interior. Sunday, chances look less likely and move over the middle Tanana Valley.

West Coast and Western Interior... - A cool, dry air mass lingers over the western half of the state, resulting in cooler temperatures through the weekend. High temperatures will be in the mid 40s in the Western Interior and will be colder along the coast. Lows will range from the upper teens across the Seward Pen and Kotzebue Sound to the low 30s in the Western Interior.

- Northerly winds will increase through the day Friday with gusts up to 30 mph through the Strait by the evening. Strong winds continue through Saturday night, peaking Saturday evening.

- Showers becomes more likely in the Western Interior Friday night/Saturday morning. Precipitation type will become snow or a rain snow mix overnight. Amounts will be light, less than a tenth of an inch liquid.

- A front lifts north across Western Alaska Sunday night into Monday morning, producing a band of precipitation which should be primarily rain.

North Slope and Brooks Range.. - Starting Friday night, the Central and Eastern Brooks Range will see chances for snow through the weekend. Daily snow accumulations look to be up to 3 inches in the heaviest places.

- Northeasterly winds, at times gusty, will gradually increase across the North Slope through Saturday night. Winds will be strongest along the Western and Eastern Arctic Coast where winds peak upwards of 40 mph.

- Northerly gap winds may be enhanced through the Central Brooks Range Passes on Friday with gusts up to 30 mph.

FORECAST ANALYSIS AND DISCUSSION

The influence of the upper-level low, which has been the primary source of the cool and showery weather this week, will begin to wane over the next few days. This morning, the low is 526 dam over southwest Alaska. Through the day Friday, the center of the low will remain relatively stationary, however upper-level high pressure shifting over Canada will point flow more directly south, allowing showers to get farther north into the Eastern and Central Interior on Friday. At the surface, higher pressure over the Arctic Ocean is creating a pressure gradient resulting in light northerly winds over most of the State. A 528 dam low, with an associated 981 millibar surface low, will approach the Gulf of Alaska from the Pacific, Friday afternoon. As it does, the gradient will tighten, strengthening winds across Northern Alaska.

The low continues into the Gulf on Saturday, further tightening the gradient at the surface and causing winds to increases, especially along the Brooks Range and along the Arctic and West Coast where pressure is higher. Winds will be strongest near Point Hope where gusts up to 45 mph are possible. The eastern Arctic Coast and Bering Strait will also likely see gusts up to 40 mph. A swath of moisture travels from southeast to northwest through the day. Also, thunderstorms will likely develop along the AlCan border in the southeast Interior. The low arriving from the south will be absorbed into the low currently over the southwest, causing it to deepen as it to deepen over Bristol Bay.

Sunday, the pattern shifts to low pressure over the Bering Sea with high pressure beginning to build over the Panhandle. The upper-level low over the southwest at the start of the forecast period is now a broad 519 dam low over the Southwest coast. It will send a front north to south through the Western Interior Sunday night with an accompanying band of precipitation. Winds through the Bering Strait should weaken as the gradient becomes more zonal. However, winds remain strong along the Arctic Coast. Temperatures should be closer to seasonally average or above as southerly flow sets up late Sunday.

FIRE WEATHER

General troughiness across the state will continue to allow for isolated precipitation chances across the Interior today through the weekend. Temperatures are expected remain on the cooler side with highs mostly in the upper 40s and lower 50s today. This weekend will likely see increasing temperatures, with some areas likely reaching 60. Areas that see a quick warm up, especially this weekend, may also see quick drops in RH as well. Minimum RHs are expected to be between 30% and 40% through the end of the weekend. Southerly winds could be gusting as high as 25 mph for the Yukon Flats, YK Delta, and SW Interior today. Thunderstorms may be isolated today, but possibly more scattered on Saturday in the SE Interior, especially Eagle, and on Sunday in Tanana Valley.

HYDROLOGY

A Flood warning is in effect through Sunday for Chalkyitsik. Public reports of an ice jam along the Draanjik has resulted in a rapid river rise.

Breakup continues along the upper Yukon as Eagle broke up earlier this week. As of earlier this morning, a 25 mile run of ice is moving through Circle with the majority of it pass the jam spots. Upstream of Eagle the river continues to breakup. Additional delayed ice runs will happen there in the next few days.

Elsewhere rivers continued to rise with several locations remaining in action stage as of this afternoon. As such river flood watches have been issued for Circle.

EXTENDED FORECAST DAYS 4-7

Monday to Thursday As an upper level trough moves to the southwest, southerly gap winds are expected to pick up in the Alaska Range passes starting Sunday night going into Monday and tapering off by Tuesday morning. Light, isolated showers are still likely for most of Northern Alaska in the form of rain, as surface conditions are expected to warm into the low to mid 60s for much of the Interior, though snow is still possible at higher elevations. Once the low moves over the Bering Sea early next week, it will draw in moisture from lower latitudes and bring another round of scattered showers to start the week. All precipitation is expected to be limited for the Interior into the middle of the week. The first low will begin to move southeast towards the Gulf of Alaska Tuesday morning as a new low is likely to enter the Bering Sea on Thursday. The second low is not currently expected to bring any impactful weather northern Alaska.

Coastal Hazard Potential Days 3 and 4...None