Fairbanks, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

621
FXAK68 PAFC 021254
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
454 AM AKDT Wed Apr 2 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

Some warmer than normal temperatures are expected today as upper
level ridging remains in place, allowing for some breaks in the
cloud cover during the day. Dry conditions will continue through
today and most of Thursday for the majority of Southcentral. The
pattern shifts on Thursday as the front extending off a North
Pacific low moves into the southern Gulf of Alaska and the
ridging shifts eastwards. As the high shifts eastwards, flow will
become more southwesterly on Wednesday, putting an end to the
gusty offshore gap winds along parts of the Gulf coast. The
pressure gradient driving these winds will essentially reverse by
Wednesday night as a coastal ridge builds along the north Gulf
Coast and over Prince William Sound. This could help a weak
Turnagain Arm wind develop that could bend into west Anchorage
late Wednesday night into Thursday morning before a down-inlet
gradient pulls the Turnagain Arm jet back away from town later on
Thursday morning.

Precipitation starts as early as Thursday evening for Kodiak
Island, reaching the north Gulf coast early Friday morning. Mostly
rain is expected at the lower elevations with snow possible in the
mountains. Snow levels initially could be low enough for wet,
slushy snow through Turnagain Pass, but warming temperatures
should transition snow over to rain even at pass level by Friday
afternoon. Thompson Pass will have the best chance for seeing
several inches of accumulating snow through the end of the week
where snow levels could stay low enough for all snow for much of
this event. Marine winds will increase to small craft
(widespread) and gale force (along the front) with an area of
storm force gusts through the Barren Islands Thursday night and
Friday. Another area of storm force gusts move along the north
Gulf coast Friday afternoon.

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Today through Saturday)...

Needless to say, there is much to talk about and discuss in the
short term.

Diving into the details, going from east to west, currently there
is still a weak low located north of Nome and a trough of low
pressure affecting the Coastal Kuskokwim Southwest with elevated
winds, fog, and very light precipitation. Observations have shown
visibilities bouncing around from a half mile to 4 miles
throughout the morning, especially around the Kuskokwim Coast,
Bethel area, and even southward into Dillingham. Sounding data
from Bethel is still showing a sharp inversion, indicating warm
air advection from a persistent onshore flow, and also in turn
preventing the moisture from mixing out into the mid and upper
levels. There is also an elongated front stretching from Nunivak
Island southwestward to Adak Station. MOS and high resolution
guidance is suggesting a brief reprieve from these conditions
today, but will deteriorate once again this evening and tonight as
the remnants of the frontal system will have enough forcing to
bring fog and light precipitation back into the picture.

Elsewhere, arguably more impactful weather is affecting the
Aleutian chain. The upper levels have aligned to form a surface
deformation snow band, enhanced by the aforementioned front that
has slowed down a bit just east of Adak Station. This is in effect
causing conditions to quickly go downhill for the Central and
Eastern Aleutians. At the same time, a deep North Pacific low is
beginning to enter the scene, which will start to supply more QPF
to the Central and Eastern Aleutians and will help to form a
robust late season, moderate to high impact winter storm. Due to
the large pressure gradient difference from a broad high sitting
west of Shemya and the North Pacific low making its way to the
Aleutian islands, northerly gap winds will also become an issue
starting late today into Thursday. Winds could reach storm force
criteria, particularly on the southern side of the Central
Aleutians as the pressure gradient forced and cold air advecting
wind is amplified by the northwest flow on the northwestern flank
of the surface low.

As the heart of the storm fully materializes, the likelihood of a
full fledged blizzard increases for the Central and Eastern
Aleutians and the Kuskokwim Coast beginning midday Thursday and
lasting through Saturday afternoon. This looks to be a rain to
snow changeover setup, with more rain possibly mixing in and
hanging on longer at sea level for the Aleutians, and considerably
more snow along favorable windward slopes of higher terrain and
mountainous regions. The duo of dynamic cooling from the upper low
in the Southern Bering and latent heat of melting cooling the
atmosphere from heavy precipitation rates will most likely change
rain to heavy wet snow for these regions. Snow and blowing snow
with reduced visibility is also possible for communities south
and east of Kipnuk. However, blizzard conditions are less likely
for these locations. There will be a rain/snow line that sets up
somewhere between the Eastern Aleutians and the AK Pen at this
timeframe late Thursday into Friday as warm 40F+ air surges into
the Southwest due to the positioning and track of the low, making
this a rainmaker for places like Dillingham and King Salmon. The
Eastern Aleutians look to be the hardest hit with 10-18" of heavy
snow (localized areas of 20"+), and strong 45-60 mph winds
possible with this system.

Likewise, the Coastal Kuskokwim Delta including Nunivak Island
will see strong winds return and snow along the frontal boundary,
which has the potential to cause blizzard conditions, in part due
to the sea ice still in place along the coast. This has prompted a
Winter Storm Watch for these regions from Thursday morning
through Saturday afternoon, with the possibility of an extension
into late Saturday and early Sunday. The biggest impacts from
heavy snow and wind will be felt Thursday evening through Friday.
Guidance does indicate that there will be some warm air intrusion
from the interior Southwest into southern portions of the
Kuskokwim Delta around this time as well, which may in turn
considerably reduce snow totals as rain mixes in or becomes the
predominant p-type for a period of time. Therefore, forecast snow
amounts for southern regions of the Kuskokwim Delta may need more
fine tuning. Snow and strong, gusty winds will slowly begin to
taper off starting late Friday and early Saturday from southwest
to northeast.

Please stay tuned to the forecast to be aware of any changes and
updates, such as upgrades from the (2) Winter Storm Watches
currently in place as we come closer to this system unfolding.

-AM/CL

&&


.LONG TERM FORECAST (Days 4 through 7: Saturday to Tuesday)...

Some increasing amplitude comes with the changes on the Alaska
Weather map through the forecast period. The upper level Eastern
Bering trough slips into the Central Alaska Mainland for Tuesday.
An upper level closed low South of Alaska Peninsula moves into the
Southern Gulf of Alaska and consolidates its link with the
Mainland trough by Tuesday. An upper ridge over the Western
Canadian Provinces adjusts to the movement and shortwaves rotating
through the pattern, while a second upper ridge builds over most
of the Bering through the period. A forecast blend of the GFS and
ECMWF maintains good continuity over the features` strength and
movement through the weekend, but the GFS slides to the South with
the Gulf of Alaska low by Tuesday.

A moderately strong surface low South of the AKPEN pushes across
the Southern Gulf of Alaska through Tuesday. Locally heavy rains
and gale force winds span from the AKPEN across Kodiak Island
through Sunday. High end gales are expected through bays and
passes. The Rain and gusty winds spread over the Southcentral
Alaska coasts to the Canadian Border through Tuesday. Locally
heavy snow is expected over higher terrain inland Monday and
Tuesday. Rain and snow extends from this low into Southwest
Alaska, with gusty winds from Nunivak Island into the Eastern
Aleutians. Out West, a well developed low and front approaches the
Western and Central Aleutians, bringing rain and gusty winds
through Monday, with most of more significant weather remaining
offshore through Tuesday.

- Kutz

&&.AVIATION...

PANC...VFR conditions and light winds will persist until late
tonight when the Turnagain Arm jet develops and could bend gusty
southeasterly winds towards the terminal.

&&


$$