574
FXAK69 PAFG 242303
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
303 PM AKDT Mon Jun 24 2024

.SYNOPSIS...
A very active pattern will bring the warmest temperatures so far
this Summer to much of the Interior on Wednesday and Thursday
while a highly unusual Bering Sea low pressure system brings near
Gale force winds to the Yukon Delta coast on Wednesday. The heat
wave will even extend to the North Slope on Wednesday and
Thursday, bringing near record high temperatures to that area.
Thunderstorms will continue to be active this week, with
relatively dry thunderstorms possible east of Chena Hot Springs
on Wednesday evening.

&&

.DISCUSSION...

Analysis and Model Discussion...
An amplified and impactful 500 mb pattern is set to impact
northern Alaska over the next week. Ridging persists over most of
the area with a tight closed low just north of Utqiagvik north of
the Arctic Coast. This low will retrograde northward, opening the
door for even stronger ridging to build into the Interior and even
north to the Arctic Coast. This will bring high temperatures nearing
or exceeding 90 degrees to much of the Interior on Wednesday and
Thursday. 80s are even expected north of the Brooks Range
approaching the Arctic Coast. Adequate 850mb temperatures in the
upper-teens C over many areas look to further support this warmth in
addition to the aforementioned and mostly clear skies. By Wednesday
morning, a tight and powerful vertically stacked closed low will move
to near St. Paul Island. This feature is highly anomalous for this time
of year, and models are progging it at 3-4 standard deviations from
normal. This feature will bring near Gale force south and southeast
winds to the Yukon Delta on Wednesday morning and 20 mph south
and southeast winds south of the Bering Strait. This will bring even
more rare elevated surf to the region for this time of year Wednesday
through Friday.

As the low transits northward on Thursday and Friday, a sharp
boundary looks to form from the Northwest Arctic Coast to the central
Alaska Range. This boundary looks to be the focus for highly active
thunderstorm activity. A shortwave also looks to bring elevated
thunderstorm activity and the possibility of dry thunderstorms
east of Chena Hot Springs on Wednesday evening.

Models are in quite excellent agreement through late work-week.

Central and Eastern Interior...Hot and dry will be the main story
through the work week with isolated thunderstorms and a few areas
of widely scattered thunderstorms. Highs will reach into the low
80s Monday and Tuesday and into the mid to upper 80s with some 90s
possible on Wednesday and Thursday. Adequate 850mb temperatures
in the upper-teens C over many areas look to further support this warmth.
Highs will likely remain in the 80s through the weekend. Lows in many
locations will struggle to drop below 60. Thunderstorms will be isolated
tomorrow, except widely scattered over the Fortymile Upland and near
Eagle. On Wednesday, a shortwave looks to rotate around the high and
possibly spark off widely scattered thunderstorms over the eastern Alaska
Range and Fortymile Uplands east of Chena Hot Springs. These
thunderstorms look to possibly be mostly dry in nature. For the Fairbanks
area, smoke from the wildfires burning in the Tanana Flats has
marginally improved this afternoon. It is expected to become
dense, once again, starting late this evening / overnight. Then,
it is expected to last through tomorrow night. Dense smoke
conditions should improve a bit by late Wednesday morning. Todays
overall smoke distribution pattern is primarily due to the winds
shifting to westerly this afternoon and back to southerly/southeasterly
late this evening / overnight and lasting into Wednesday morning.
The HRRR Smoke model picks up on this pattern quite well. So, we
went with that for the timing. It looks like it may even be more
dense tonight into tomorrow as the model is picking up on values
up to around 1,000 and nearing 1,500 for a few spots for that
timeframe.

West Coast and Western Interior...Strong ridging over the Interior
and the influence of the low in the Bering Sea over the West Coast
will create a mix of conditions over the area over the next week. As
the low moves north, expect near Gale force winds and some rain along
the Yukon Delta coast on Wednesday. In the Interior, highs will be
in the mid 70s to lower 80s under mostly sunny skies with areas of
smoke near active fires, with temperatures trending upwards
through Wednesday. Lows will also get warmer each day through
Thursday. Thunderstorms will be widely scattered near McGrath this
afternoon and from McGrath to Lake Minchumina on Tuesday. Storms
will be isolated across the rest of the Interior on Tuesday.
Wednesday and Thursday look to bring additional isolated
thunderstorms.

North Slope and Brooks Range...The patchy fog and low stratus along
the coast from this morning will becoming less and less extensive the
next couple of nights as the closed low aloft moves offshore and
is replaced with ridging. Temperatures will rise each day, with a
full on North Slope heatwave expected starting Wednesday. Highs
will be in the 80s inland, with 60s and 70s along the coast
Wednesday and Thursday. Strong thunderstorms are possible Thursday
over the western Brooks Range. Otherwise, thunderstorms will be
isolated over the eastern Brooks Range each afternoon. Notably, portions
of the North Slope look to be only 2 to 3 degrees below record high
temperature criteria for the Wednesday and Thursday timeframe.

Coastal Hazard Potential Days 3 and 4...The aforementioned low
pressure system in the Bering Sea will bring elevated surf 1 to 3
feet above the normal high tide line along the Yukon Delta coast
as well as south facing shorelines south of the Bering Strait
including Nome. Water will be elevated Wed-Fri with multiple water
level peaks as storm surge values remain fairly constant and tides
go in and out.

&&

.FIRE WEATHER...
Fire weather continues to be a concern with hot and dry conditions
and active thunderstorm days all in the forecast. Today, expect
highs in the mid 70s to low 80s across the Interior. RHs will
reach critical values (<25%) east of Delta Junction. Winds will remain
light. Tuesday will be a few degrees warmer yet, though RHs will
generally remain above critical values. Wednesday and Thursday are
the real scorchers with highs nearing 90 and min RHs 20-25% east of
Tanana. Could see Red Flag or near Red Flag conditions for
hot/dry/windy conditions for Thursday and Friday east of Galena.
Otherwise, winds will remain below 15 mph.

Thunderstorms will be active each day this week. This afternoon, expect
widely scattered thunderstorms from McGrath south to the Western
Alaska Range and isolated thunderstorms elsewhere south of the
Brooks Range and east of Ruby. Tuesday will see widely scattered
thunderstorms from McGrath to Minchumina and over the Fortymile
Uplands with isolated storms across the rest of the Interior and
eastern Brooks Range. Wednesday will feature widely scattered
thunderstorms across the eastern Alaska Range and Fortymile
Uplands. These storms look to be drier in nature under the strong
ridge. Isolated storms are expected across the rest of the Interior on
Wednesday. Thursday and Friday have the potential to be big lightning
days, with most of the activity focused on the boundary between the
ridge and the influence of the low in the Bering Sea.

&&

.HYDROLOGY...
Recent heavy rains have led to higher water levels along the
Fortymile River, but drier conditions expected over the next
several days will allow water levels to recede  this week.
Glacial fed rivers including the Tanana may begin to rise as
warming temperatures lead to increased high elevation snowmelt.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Dense Smoke Advisory for AKZ839-840.
     Dense Smoke Advisory for AKZ844.
PK...Small Craft Advisory for PKZ850.

&&

$$