textproduct: Fairbanks

SYNOPSIS

A weather front has arrived in southwest Alaska this morning, and has brought along with it a mixture of light snow and rain showers and moderate winds to the YK Delta. These showers will expand up into the Western Interior by Tuesday night, and gradually taper off as they move into the Interior Wednesday. The eastern Interior will see a slight resurgence of precipitation Wednesday night, before the system exits to Canada by the end of the day Thursday. By then, another front will arrive in the Bering Strait, bringing strong southerly winds and another band of precipitation to the West Coast. Southerly flow will keep temperatures across our area at or above seasonal average through the start of next week.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Seasonable temperatures continue through next week, with highs remaining in the 30s to low 40s. Lows will also trend to being well above zero for most locations, as additional cloud cover moves in.

- Southerly gap winds will strengthen through Alaska Range Passes Tuesday morning through Wednesday, with gusts through Isabel Pass up to 50 mph possible.

- A front will move into the Interior Wednesday into Thursday producing a mix of snow and rain showers as temperatures oscillate between above and below freezing.

West Coast and Western Interior...

- A front has arrived in Southwestern Alaska and will continue to bring showers through Wednesday. Precipitation will begin as snow Tuesday morning, with a mix of rain and snow showers as warmer temperatures build in Tuesday afternoon.

- Easterly to northeasterly winds strengthen along with the approaching front. The YK Delta, Lower Yukon, Nulato Hills and southern Seward Peninsula will have winds gusting up to about 20 mph Monday afternoon through Tuesday. Areas along the coast as well as St. Lawrence Island could see gusts above 30. - By early to mid next week, highs are expected to climb well into the 20s and 30s to low to mid 40s further inland, with lows in the teens/20s to low 30s further inland as cloudier conditions return.

- Strong southerly winds develop through the Bering Strait Thursday morning. The Bering Strait and Northwest Arctic coasts will see wind gusts of 40 to 45 mph Thursday and Friday. - By the end of the week, models are trending towards a pattern of more active weather for the West Coast and Western Interior.

North Slope and Brooks Range...

- Mostly clear skies and dry conditions with light winds will continue across the North Slope and Brooks Range through Thursday. - Beginning Thursday, temperatures rise significantly, reaching 20s to 30s above as southerly flow is directed into the North Slope.

- Overnight lows will continue to be coldest across the Arctic Plains/Coast around -10F to -20F through Wednesday, with above zero lows by the latter half of the week.

- A band of precipitation arrives at the Northwest Arctic Coast/Western Brooks Range Thursday afternoon and continues east across the North Slope through Friday.

FORECAST ANALYSIS AND DISCUSSION

Satellite depicts a cyclone in the Bering Sea with cloud cover from the YK Delta to the Alaska Range. Models depict the main cyclone as a 523 decameter upper-level low stacked on top of a 992 mb surface low. At time of writing, it is snowing across the lower Yukon.

Through the day today, moisture will be advected northward into the Western Interior as the low in the Bering moves along the Aleutian Peninsula. Initially, the precipitation type should be predominantly snow, as temperatures in the YK Delta and southwest Interior remain at or below freezing through Tuesday morning. However, it should transition to rain or a rain/snow mix as temperatures rise Tuesday afternoon. Winds behind the front will be northeasterly and gust above 20 mph for areas in the YK Delta and likely above 30 mph for areas along the Coast and for St. Lawrence Island.

By Tuesday evening, the main low will be just moving over the YK Delta. Light showers will extend up into the Western Interior, remaining a mixture of rain and snow as temperatures rise along with peak solar heating and warm air advection. As surface pressure falls in the Interior Southerly winds through Alaska Range strengthen, up to 40 to 50 mph through the eastern passes.

Light showers progress eastward on Wednesday, but the lack of a definite frontal boundary appears to reduce overall precipitation amounts. It isn't until we see an upper-level trough drop south over the eastern Interior Wednesday night into Thursday, that we see more significant precipitation chances return for Thursday.

On Thursday the low exits to the east into Canada, and with it the last remnants of showers in the Interior. However, another front will approach from the West. The main low for this front will be over Siberia, but impressively, the swath of moisture it is pulling spans from the Aleutians all the way to the North Slope. A band of precipitation sweeps across Alaska from west to east Thursday evening into Friday. We will also see southerly winds through the Bering gusting up to 40 to 45 mph as the gradient tightens between the low over Siberia and high pressure reestablishing over Alaska. The southerly flow will result in above average temperatures for Northern Alaska, especially along the western half of the North Slope, where temperatures could get above freezing.

EXTENDED FORECAST DAYS 4-7

At the start of the extended period on Friday, we see a 980mb low has made it north of Siberia. A swath of moisture is directed from the northern Pacific into the Western Interior, producing a band of precipitation from the YK Delta to the North Slope. That band will ride over a ridge in the Gulf of Alaska, sweeping eastward across the state through Friday. The lows westerly trajectory will result in weakening winds through the northern Bering Strait on Friday. However, flow into western Alaska will remain southerly as another low arrives in the Bering Sea, Friday evening. Temperatures should be above seasonal average through the weekend and into the start of next week. In the Interior, expect peaks in the 40s above, with overnight lows still dipping below freezing at night. Along the West Coast, temperatures should get above freezing more regularly but still remain cooler, below 40F. Along the North Slope, temperatures will be well above average, with the western half potentially getting above freezing Friday and Saturday. Otherwise, temperatures in the 20s above are expected through the weekend.

Confidence has improved with respect to another surface low that arrives in the Bering Sea Saturday morning. Ensemble low locations are in fairly good agreement on the feature advancing slowly along the Siberian coast on Friday, then model solutions diverge between having it continue north or take a detour through the Bering Strait. The main difference between these two paths is the extent of precipitation along the West Coast, with the Bering path producing more substantial rain/snow showers farther into the Western Interior. Regardless, the system should be low impact and the Interior and North Slope remain generally clear and calm through the extended.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Brisk Wind Advisory for PKZ816. Brisk Wind Advisory for PKZ817. Brisk Wind Advisory for PKZ850. Brisk Wind Advisory for PKZ851. Brisk Wind Advisory for PKZ852-853. Brisk Wind Advisory for PKZ854.