textproduct: Fairbanks

SYNOPSIS

The remnants of a stationary front will be placed over the Alaska Range and Upper Tanana Valley, supporting rain showers, downpours and isolated thunderstorms today. On Sunday, there will be a lot of moving parts that we'll get into in the forecast analysis and discussion section. Nonetheless, there is a chance for moderate to heavy rain across the Western/Central Interior and southern Brooks Range from Sunday afternoon into Monday. Winds will ramp up Sunday afternoon and continue through Monday afternoon with southwesterly gusts upwards of 45 mph above 1500ft elevation, and 35 mph in Interior valleys leading to some tricky travel possible. Heading into the new work week, most of the lingering rain and wind on Monday will exit during the evening and overnight, leaving much drier and calmer weather by Tuesday as a ridge builds in.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Much drier weather overall today, showers and isolated thunderstorms linger near the AK Range and Upper Tanana Valley through tomorrow morning.

- Moderate rain with pockets of heavy rain is possible, if not, probable over the Interior with a widespread 0.25 to 0.75" expected from Fairbanks to Coldfoot, including the White Mountains and Koyukuk Valley.

- Expect it to be windy Sunday afternoon through Monday afternoon, causing some wind swept heavy rain in spots. SW wind gusts upwards of 45 mph over 1500ft elevation and 35 mph in Interior valleys, excluding the Upper Tanana.

- Much calmer, drier and warmer weather returns on Tuesday with our first 70s popping up around the Interior.

West Coast and Western Interior... - Quiet weather persists with patches of dense fog over Norton Sound and the YK delta Coast, otherwise partly to mostly sunny elsewhere.

- Rain showers with a couple of thunderstorms develop Sunday afternoon. These could come with pockets of heavy rain, especially from Holy Cross northeast to Lake Minchumina.

- Gusty southwest winds are expected Sunday afternoon through Monday afternoon with gusts upwards of 45 mph above 1500ft and 35 mph in Kuskokwim Valley.

- Much calmer, drier and warmer weather returns on Tuesday with our first 70s popping up around the Interior.

North Slope and Brooks Range.. - Chilly weather persists with below normal temperatures through early next week. Temperatures approach normal values on Tuesday.

- Areas of light snow move into the region on Sunday with less than 1 inch of snow on the North Slope and 0.5 to 2 inches in the northern Brooks Range.

- Gusty southerly winds up to 45 mph and moderate rain develops in the southern Brooks Range on Sunday and persists through Monday evening before ending thereafter. Rainfall amounts of 0.25 to 0.50 inches are expected with localized higher amounts possible.

FORECAST ANALYSIS AND DISCUSSION

It's a bit of a messy pattern with a trough extending into the Interior from a closed upper low in the Arctic, a closed upper low in the Gulf as well as in the eastern Aleutians and a ridge in eastern Siberia. All of this is what brought a stationary front to the Interior last week. This stationary front has now gradually shifted south over the AK Range which is where we expect the bulk of the wet weather today into tomorrow morning. By the time Sunday afternoon rolls around, the front will lift back to the north and interact with a trough dipping south into the Brooks Range. The details here are crucial and models are still struggling with where to place the trough axis. The ECMWF/CMC cut this trough into the ridge and push it over the Brooks Range then into the Western Interior. This solution would bring the front west, allowing for moderate rain in the Western and Central Interior. The GFS however, keeps the trough axis over the Central Brooks Range, then pushes it east as the ridge builds in behind it. This solution would place the front farther east, bringing most of the rain to the Central/Eastern Interior, but also cut off the moisture from the southwest, leading to less rain all together. There is some support for the GFS coming from the ECMWF AI and GFS AI models. It's hard to believe that this trough will blast over the mountain range and into the ridge, like the ECMWF/CMC are saying. We are taking more of a middle ground approach, which is similar to the GFS and AI models. We expect showers over the Western Interior beginning Sunday afternoon, but the heaviest rain will be situated over the Central Interior with lighter showers in the Eastern Interior. From Fairbanks to Wiseman, expect 0.25 to 0.75" of rain from Sunday afternoon through Monday afternoon. Some spots in the higher terrain may receive 1.00", especially towards the Steese and Dalton Highway summits. Elsewhere, rainfall amounts will be around 0.10 to 0.25" with a higher end potential of 0.75" possible from Bettles to Lake Minchumina. The higher rainfall totals are dependent on the placement of the trough axis.

As if this weren't enough, wind gusts will increase from the south and west Sunday afternoon in the Interior and southern Brooks Range. Expect them to be up to 45 mph above 1500ft and up to 35 mph in valleys outside of the Upper Tanana through Monday afternoon. Regardless of the exact outcome, a wind swept rain is expected across much of the Interior and southern Brooks Range. All of the rain and wind will end late Monday evening as the trough exits into Canada. This will allow for much drier, calmer and warmer weather as the Siberian Ridge builds in from the west. Temperatures are expected to be near normal on Tuesday with highs in the 60s to low 70s. A warming trend may continue through the middle of the week.

FIRE WEATHER

Generally quiet on the fire weather side. Most of the isolated wet thunderstorm chances today will be around the AK Range with a slight tick north to the Kuskokwim and Tanana Valley Sunday afternoon, though the chances are low. Southwest winds will pick up in the Interior Sunday afternoon through Monday afternoon with gusts to 45 mph above 1500ft and 35 mph in the valleys. Fortunately, there will be cool temperatures and high chances for wetting rains. Temperatures remain cool with highs in the 50s and low 60s through Monday. This changes on Tuesday as high temperatures surge into the upper 60s to low 70s across much of the Interior and parts of the West Coast. The middle of the week features the warmest temperatures of the season with highs persisting in the 60s and 70s. Min RHs are expected to be in the teens and 20s with the lowest expected in the Eastern Interior valleys on Tuesday and Wednesday. Thunderstorm chances remain low through the middle of the week.

HYDROLOGY

No major concerns on the hydro front.

Sagavanirktok River: Some overflowing is occurring; however, breakup along the Sag River has not begun yet. High temperatures are expected to increase to around the mid to upper 30s and even low 40s on Monday with low temps in the 20s and 30s (north to south). Tuesday and Wednesday appear to be the warmest days with highs in the 30s to near 40 along the coast and low 50s towards the northern Brooks Range. Temperatures will then dip back down later in the week, exact values are uncertain. Near the Sag River source on the north Brook Range, high temperatures could reach the mid 50s from Monday to Wednesday, with snow levels reaching upwards of 4000 ft. Again, temperatures look to cool going into the late week but continue to be above freezing.

EXTENDED FORECAST DAYS 4-7

There are no major concerns expected through next weekend. The main feature we are monitoring are a Siberian ridge which will be extending into the Interior and phasing with a ridge over Canada. This would bring warmer, near to above normal temperatures through the middle and end of the week across most of Northern Alaska, including the North Slope and Brooks Range. The next feature is an Arctic low which will try to push cooler temperatures into the Interior by Friday or Saturday. Models are in disagreement with how far south this low gets and how far cooler air intrudes into the Interior. Nonetheless, after a brief warm up on the North Slope and Brooks Range through mid week, it does look to cool once again, most likely near or below normal. The Interior is a little less certain, but expect warm temperatures through the end of the week with cooling possible by the weekend. There are no significant precipitation events or wind events expected next week.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...None.