826
FXAK69 PAFG 132329
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
329 PM AKDT Thu Jun 13 2024

SYNOPSIS...
Cool conditions cover the Southern and Western Interior along
with isolated to scattered showers and a few PM Thunderstorms,
while the NE Interior is hot and dry with isolated thunderstorms.
The Interior will become warmer and drier Fri with isolated
thunderstorms in the Eastern Interior. Some of those thunderstorms
over the NE Interior will be dry and increase the possibility of
fire starts. The Interior will become hot and dry over the
weekend, much like last weekend, but without the wind. There will
be a few thunderstorms over the Eastern Interior Sat and Sun.

The West Coast is cool with areas of fog, and there are isolated
to scattered showers west of Nome and Kivalina. Similar
conditions will continue into Fri, then expect showers to end and
fog to become more widespread Fri night into Sun.

Over the North Slope, unusually clear skies continue today.
A broad area of stratus and fog over the Beaufort Sea is expected
to move SW over the Eastern Arctic Coast this evening, and to
Utqiagvik late tonight. Expect stratus and fog to remain along
the Arctic Coast from Utqiagvik east Fri and Fri then thin at
Utqiagvik Sat. West of Utqiagvik, increasing clouds and isolated
showers will continue into tonight along with near normal
temperatures, followed by cloudy skies southwest winds of 15 to 25
mph and isolated to scattered showers and above normal temps Fri
into the weekend. The inland North Slope and Brooks Range will
remain very warm and dry through the weekend, with isolated PM
thunderstorms in the Central Brooks Range today through Sat.


Surface pattern...
A thermal low pressure trough stretching from Chicken to Livengood
to Anaktuvuk Pass to Point Hope will move t o Chicken to Atigun
Pass to Umiat by 4pm Fri, and to Chicken to Arctic Village by 4pm
Sat, then remain there into Sun. This will be the focus for
thunderstorms the next several days.

A vertically stacked 1014 mb low in the Gulf of Anadyr will move
to 300 NM west of Point Hope as a 1011 mb low by 4pm Fri, to 300
NM northwest of Utqiagvik as a 1012 mb low by 4pm Sat, and to 200
NM northwest of Utqiagvik as a 1014 mb low by 4pm Sun. This is
causing is cool with areas of fog, and isolated to scattered
showers along the West Coast that will spread north over the
Western Arctic on the weekend. scattered showers and above
normal temps Fri into the weekend.

High pressure over the Beaufort Sea will persist into Sun. This
will cause east winds along the Arctic Coast east of Utqiagvik
along with pushing in stratus and fog tonight and keeping it there
into Sun.

High pressure over SW AK will build over the West Coast Fri and
Sat and then persist into Sun. This will cause stratus and fog
along the West Coast that will persist through Sunday, becoming
thin in the afternoon and evenings, and becoming more dense
midnight to morning.

&&

.DISCUSSION...
Aloft at 12Z, models initialize 10-20 meters to low on heights
under the strong high that is building over Northern AK. Expect
that this will remain slightly stronger than forecast into Fri and
possibly into the weekend. This will result in a stronger
subsidence inversion that forecast by models and thus slightly
less convection.

Models show similar solutions aloft through 4pm Sat, then the
ECMWF, Canadian and NAM keep the low aloft over the CHukchi Sea
closer to NW Alaska than does the GFS. Although the GFS is the
outlier on Sat night and Sun, favor the GFS solution aloft Sat
night and Sun since the strong omega block with a high over
Mainland AK should be stable for several days and possibly longer
since the solar heating over AK under this high should re-enforce
the high heights of the ridge. Bottom line for features aloft is
that we will use a blend of models aloft through 4pm Sat, then
transition to the GFS for Sat night and Sun. We will also account
for the stronger than forecast ridge over Nrn AK through Fri by
having slightly less convection than models might indicate.

The long wave pattern will consists of an omega block with the
blocker high over mainland AK, a low over the Gulf of AK, another
low over the

At 850 mb, temperatures range from +10C over the NE Interior and
INland areas of the North Slope to 0C over the Western Seward Pen
and YK Delta west. By Fri the 0C isotherm will be from the Seward
Pen and Point Hope NW, while the +10C isotherm is over the
Eastern North Slope and much of the Eastern Interior. By Sat the
+10C isotherm covers the Central and Eastern Interior and Brooks
Range, while the West Coast warms as does the Arctic Coast. All
areas warm 1-2C on Sun. Surface temps will follow suit expect for
areas with seas or land breezes.

With precipitation, no areas receive significant precip through
the weekend other than isolated areas under PM thunder storms
today and Fri. Sat and Sun will be mainly dry most areas.

At the surface at 15Z, models verify well on most features. Models
show similar solutions at the surface through Sun. Sustained
winds over the Interior remain less than 15 mph through the
weekend. The Eastern Arctic Coast has east winds of 15 to 20 mph
tonight through Fri. South winds 15 to 25 mph in the Bering
Strait and near Point Hope Fri into Sat.

Coastal Hazard Potential Days 3 and 4...None.


&&

.FIRE WEATHER...
A thermal low pressure trough stretching from Chicken to Livengood
to Anaktuvuk Pass to Point Hope will move t o Chicken to Atigun
Pass to Umiat by 4pm Fri, and to Chicken to Arctic Village by 4pm
Sat, then remain there into Sun. This will be the focus for
thunderstorms the next several days.

Cool conditions cover the Southern and Western Interior along
with isolated to scattered showers and a few PM Thunderstorms,
while the NE Interior is hot and dry with isolated thunderstorms.
The Interior will become warmer and drier Fri with isolated
thunderstorms in the Eastern Interior. Some of those thunderstorms
over the NE Interior will be dry and increase the possibility of
fire starts Fri. The Interior will become hot and dry over the
weekend, much like last weekend but without the wind. There will
be a few thunderstorms over the Eastern Interior Sat and Sun.

&&

.HYDROLOGY...
High water from snowmelt has made its way down
rivers to the coast on the Central North Slope. The high water is
caused by warm temperatures and snow melt in the Brooks Range. It
is expected that water levels will fall slowly through the weekend
and into next week.

Periods of heavy showers fell along the North Slopes of the
Alaska Range, and over the Goodpaster River Basin, and the Upper
Charlie and Upper Fortymile River Basins the past two days. Rain
fall amounts range from one half to one and one half inches, with
the heaviest amounts along the Alaska Range east of Denali Park.

This rain has caused rapid rises on streams and small rivers in
steep terrain. The streams and small rivers should peak today and
begin to fall tonight. Larger rivers such as the Tanana, the
Delta, the Nabesna and the Chisana Rivers should rise over the
next several days. Although no flooding is expected, people in
the Alaska Range east of Denali Park, and along the Goodpaster,
Charlie and Fortymile Rivers should be alert to high river levels
through tonight.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Red Flag Warning for AKZ933-935.
PK...Brisk Wind Advisory for PKZ814-815.
&&

$$

JB