275
FXAK69 PAFG 012013
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
1213 PM AKDT Mon Jul 1 2024

.SYNOPSIS...
Ridging aloft is weakening and the shift in the pattern is
beginning as temps are falling over the S Interior. Southwest
winds increase through Wednesday and will become quite blustery,
especially over the N Interior, with gusts over 30 mph. These
winds should also begin to result in improvements in wildfire
smoke over the Interior, although some smoke may filter into the
valleys the next couple evenings.

Rain and cooler temps begins to move in Wednesday evening across
the Interior, and will continue through the week. Gale force winds
and rain will also impact the West Coast, and will bring some
elevated water levels from Norton Sound to the Chukchi Coast.

&&

.DISCUSSION...

Upper Levels and Analysis...
A remnant skinny ridge aloft persists over the Interior,
stretching from the Norton Sound to the E Interior. There is a 548
dam upper low over the AKPEN with another mobile low over E
Siberia. There is a departing 523 dam low over the Arctic moving
departing to the east across the Canadian Archipelago. Light
rainfall and showers is occurring over parts of the Tanana Valley
in association with a subtle easterly wave aloft and a deformation
zone. Smoke has improved over the Interior due to this rainfall as
well as increasing southwest winds aloft.

Model Discussion...
Models are in good agreement and a blend of all models was
favored. We favored NAM nest hi-res winds for the strong
southwest winds expected the next couple of days. For rainfall, we
favored a blend to the GFS.

Central and Eastern Interior...
Rain showers over the S Interior will continue on and off through
Tuesday morning. Isolated thunderstorms this afternoon will
develop over the higher terrain and drift southeast, some may make
it into the valleys as well. Heavier rain showers are most likely
over the Fortymile and E AK Range. Southwest winds this afternoon
will continue to ventilate smoke off the the northeast,but some
will likely move into the Interior valleys overnight, however, it
should not be as dense as the last few days.

Tuesday, showers in the morning taper and southwest winds are
becoming breezier than today, 15 to 20 mph across most locations,
but 20 to 25 mph over the N Interior with gusts to 35 mph. A few
mountain showers with isolated thunderstorms will still be
possible over the E Interior, but overall, it will be drying out
with tomorrow being the final near or above seasonal norms.

Wednesday, temps fall again and winds are peaking from the
southwest 15 to 30 mph, gusting to 40 mph over the N Interior and
Yukon Flats. Light rainfall is moving south and will reach the
Alaska Range by the evening. Heavier rainfall is moving into the
Interior by the evening of the 4th of July.

West Coast and Western Interior...
Rain showers and isolated thunderstorms will continue moving
across the Yukon Valley and into Norton Sound and then fall apart
by tonight. More afternoon isolated thunderstorms are possible
over the Interior and up to the W Brooks Range, otherwise, it will
be another warm day with temps overall in the 70s, but a few
degrees cooler than yesterday.

Attention turns to a strong gale force front moving to the NW
Arctic early Tuesday morning, and then shifting inland Tuesday
evening. This front will bring a continuous period of southwest
winds to 25 to 35 mph and periods of rainfall through the weekend.
Rainfall amounts will be 2 to 4 inches over the SW brooks Range
with a general 1 to 2 inches elsewhere, by late weekend. In
addition, expect elevated water levels of 2 to 3 feet and high
wave action along the West Coast, from Norton Sound to the Chukchi
coast. Temps are trending down quite a bit through the week.

North Slope and Brooks Range...
High pressure along the coast is weakening which has allowed for
some sun to peak through along the coast. Expect an isolated
thunderstorm over the Brooks Range through this evening. Tuesday
is a big change with a fast moving front shifting east, bringing
southwest winds 15 to 30 mph and rainfall, which will move from
the NW Arctic and reach the E Arctic and Brooks Range by Tue
night. There will be a break in rainfall with intermittent showers
Wed night into Thursday before more rainfall commences into
Friday. Rainfall amounts will range from 2 to 4 inches over the W
brooks Range to 0.5 to 1 inch elsewhere, with 1 to 2 inches over
the E Brooks Range.

Extended Forecast Days 4-7...
Friday onward, there will be continued westerly flow moving
onshore and inland, which means bouts of rainfall will continue
through the weekend. By early next week, the flow pattern will
amplify and rainfall may shift back west, which could allow for
some light Interior ridging over the ALCAN to bring temps back up
a bit, but overall, it does not look like a return any hot and dry
for a while.

Coastal Hazard Potential Days 3 and 4...Strong southwest winds to
gale force will bring elevated water levels of 2 to 3 feet above
the normal high tideline from Norton Sound to the Chukchi coast
beginning Tue and lasting into late week.

&&

.FIRE WEATHER...
Very active fire weather conditions remain in place through
Wednesday, as the upper ridge axis breaks down and the flow
becomes more westerly. Today, expect the first day of southwest
winds to develop by this afternoon, with 5 to 10 mph across most
of the Interior. Isolated wet thunderstorms with an area of widely
scattered thunderstorms are possible from the White Mtns to the
Fortymile Uplands. Rain showers this morning have put down some
light wetting rains and have also dampened temps across the Tanana
Valley and toward the AK Range. Steering winds will be northwest
this evening over the Interior highlands, so some storms may move
off the higher terrain into the valleys.

Fairly significant fire weather conditions begin Tuesday which is
drying back out some with increased southwest winds of 10 to 15
mph over most of the Interior, and 15 to 20 mph over the N
Interior, and 15 to 25 mph with gusts near 35 mph over the Yukon
Flats and Upper Koyukuk Valley. Critical fire weather conditions
look likely over the northern half of the Interior, as temps will
be around 75 to 80, and minimum RH in the upper 20s to near 30 %,
thus a red flag warning is now in effect for the N Interior zones
from the Dalton Hwy east.

The gradient continues to increase overnight, thus winds will only
weaken partially and likely remain mixed out from the Fairbanks
area northward. Winds on Wednesday are stronger yet, with
widespread 15 to 20 mph, and 20 to 25 mph and gusts to near 40
mph over the Yukon Flats and Dalton Highway corridor, and into the
S Brooks Range slopes. However, temps are falling and
precipitation will be possible by Wednesday afternoon in the form
of rainfall, so minimum RH looks to be higher, into the upper 30
to mid 40 % range.

The onset of wetting rains looks fairly low through Wednesday,
with increasing chances by Wednesday night, and high chances on
Thursday and Thursday night. The lone holdout will be the Yukon
Flats which will see downslope drying and little in the form of
rainfall.

&&

.HYDROLOGY...
Glacial fed rivers including the Tanana are slowly rising as
warming temperatures lead to increased high elevation snowmelt and
glacial melt.

Beginning next week around Wednesday, heavy rainfall will move
across the W Brooks Range with 2 to 4 inches of rainfall through
next weekend, with 0.75 to 1.5 inches over parts of the Interior.
Expect river rises with this amount of water across the Mainland.
Expect significant rises on rivers draining the Brooks Range
including, but not limited to, the Wulik, Kobuk, Noatak, and
Koyukuk Rivers and smaller creeks and streams.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

AK...Red Flag Warning for AKZ911-932-933.
PK...Small Craft Advisory for PKZ802-803-808-852.
     Small Craft Advisory for PKZ804-809-855.
     Small Craft Advisory for PKZ805.
     Small Craft Advisory for PKZ806-807-812-858.
     Brisk Wind Advisory for PKZ810.
     Small Craft Advisory for PKZ811-816-817-854-857.
     Small Craft Advisory for PKZ850-853.
     Small Craft Advisory for PKZ851.
     Small Craft Advisory for PKZ856.
     Brisk Wind Advisory for PKZ859-860.
&&

$$

Ahsenmacher