987
FXAK69 PAFG 122329
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
329 PM AKDT Wed Jun 12 2024

.SYNOPSIS...
The Interior has cool and wet conditions, except the Northern
Interior which remains warmer and drier, and will trend warmer
and drier from Thu into the weekend. Numerous showers and widely
scattered thunderstorms lie in a band from Chicken to Denali to
Huslia now with scattered showers and isolated thunderstorms just
north and south of this band and extending from Huslia to Point
Hope. The thunder will taper off late tonight with the showers
diminishing by Thu AM. The heaviest showers will be east of
Denali. On Thu expect scattered showers and isolated thunderstorms
from Chicken to Fairbanks to Howard Pass. On Fri and Sat expect
isolated thunderstorms from Chicken to Anaktuvuk, but they will be
high based with low precip and the potential for dry lightning.

The North Slope is sunny and warmer than normal, and will remain
warmer than normal through Fri. The coast will see fog and
stratus clouds move onshore late tonight and then persist into
Fri. The North Slope will cool and cloud up over the weekend.

The West Coast is cool and wet with areas of fog, and will remain
cool with areas of fog and a chance of rain into Fri. The West
Coast warms and dries over the weekend.

Surface Pattern...
There is a thermal low pressure trough stretching from Chicken to
Tanana to Point Hope with another trough stretching from Huslia
to Anvik. This trough will move to Eagle to Coldfoot to Point Lay
Thu, and to Northway to Coldfoot to Anaktuvuk Pass on Fri, and
remain there into the weekend. The warmest and driest conditions
will remain northeast of this trough.

Strong high pressure north of the Arctic Coast will persist into
Fri and then weaken over the weekend.

A vertically stacked 1010 mb low 200 NM southwest of Gambell will
move to the Gulf of Anadyr as a 1016 mb low by 4pm Thu, and to
100 NM south of Wrangel Is as a 1011 mb low by 4pm Fri, then to
300 NM northwest of Utqiagvik as a 1015 mb low by 4pm Sat. A low
pressure trough extending south from this low will move along the
West Coast on Thu, and over NW Ak on Fri, and then over the
Western North Slope on Sat. This low and trough will bring
isolated to scattered showers and cooler air north with it. These
will also bring southwest wind 25 kt Sat over NW AK.

&&

.DISCUSSION...
Models initialize well aloft at 12Z and show similar solutions
aloft through 4am Sat, then the Canadian model bring the strong
low aloft over the Chukchi Sea southeast of NW AK, while the other
models are much slower bringing this feature south of the West
Coast of AK next week. At this time favor the slower movement of
this feature given the strength of the blocking ridge building
over AK this weekend. Will use a blend of the GFS/ NAM and ECMWF
models through Sat for features aloft.

The long wave pattern consists of a Rex Block with a strong high
north of the Arctic Coast of Alaska, a low over the Gulf of
Alaska, and a series of weak short waves moving east across
Interior and West Coast of Alaska today into tonight. These short
waves will help to focus convective showers today and tonight. A
strong low over the Northern Bering Sea will move over the
Chukotsk Peninsula on Thu, and another low will move from near
Shemya to the Central Aleutians Thu. The ridge builds south over
Mainland AK on Thu forming an omega block with the blocking ridge
persisting over Mainland AK through the weekend. This will cause a
warming and drying trend over the Interior and North Slope
through Fri while the West Coast sees cooling from the cold low
aloft moving into the area. The North Slope will cool and cloud up
over the weekend while the West Coast warms and dries over the
weekend.

A short wave trough that stretches from Eagle to Fairbanks to
Ambler to Point Hope will move to Chicken to Denali to Point Hope
by 4am Thu, and to Northway to McGrath to Point Lay by 4pm Thu.
This is causing the enhanced showers that will taper off late
tonight or Thu AM, along with to widely scattered thunderstorms
this PM. Showers will taper off as the ridge builds south over the
trough area.

A second short wave trough will move south to the Arctic Village
east Thu, and to the SE Interior Thu night. This will help set off
isolated PM thunderstorms over the Eastern Interior Thu PM.

A third short wave will drop south over the Eastern Interior Fri
PM with a fourth short wave following the track on Sat. These
could bring isolated PM thunderstorms, but due to the warming and
drying airmass they will likely be dry.

With precipitation, models show similar areas through Sat, but the
GFS and ECMWF produce greater coverage and amounts for Fri and
Sat. Given the building ridge on Thu and Fri and continuation into
the weekend, expect showers to decrease in areal coverage through
Fri. Do expect another 0.50-1.00 inch of rain along the Alaska
Range east of Denali Park through Thu AM. Could see 0.25-0.50 inch
from Denali to Point Hope through Thu am as well.

With convection, numerous showers and widely scattered thunderstorms
lie in a band from Chicken to Denali to Huslia with scattered
showers and isolated thunderstorms just north and south of this
band and extending from Huslia to Point Hope. The thunder will
taper off late tonight with the showers diminishing by Thu AM.
The heaviest showers will be east of Denali. On Thu expect
scattered showers and isolated thunderstorms from Chicken to
Fairbanks to Howard Pass. On Fri and Sat expect isolated
thunderstorms from Chicken to Anaktuvuk, but they will be high
based with low precip and the potential for dry lightning.

At the surface models verify well and show similar solutions
through Sat. Winds remain below 25 kt sustained through Fri, with
southwest 25 kt possible Sat over NW AK. Over the Interior winds
should remain below 15 mph sustained through Sat.

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


&&

.FIRE WEATHER...
Cool and wet conditions over most of the Interior, except the
Northern Interior which remains warmer and drier, will become
warmer and drier from Thu into the weekend. Numerous showers and
widely scattered thunderstorms lie in a band from Chicken to
Denali to Huslia now with scattered showers and isolated
thunderstorms just north and south of this band and extending from
Huslia to Point Hope. The thunder will taper off late tonight
with the showers diminishing by Thu AM. The heaviest showers will
be east of Denali. On Thu expect scattered showers and isolated
thunderstorms from Chicken to Fairbanks to Howard Pass. On Fri and
Sat expect isolated thunderstorms from Chicken to Anaktuvuk, but
they will be high based with low precip and the potential for dry
lightning.

&&

.HYDROLOGY...
High water on rivers of the Central North Slope such as the
Colville, the Kuparuk and the Sagavanirktok will fall slowly
through the weekend, and then fall more next week. Minor flooding
is possible along these rivers in low lying areas near the coast
the next several days.

Showers along the North Slopes of the Alaska Range, and over the
Goodpaster River Basin, and the Upper Charlie and Upper Fortymile
River Basins started yesterday and will continue into Thursday
morning. Showers will be heavy at times. Most of this area has had
between one half inch and one inch of rain, with another inch of
rain expected through Thursday morning. By the time the rain
tapers off on Thursday this will make a two day rainfall total of
between one and two inches with the heaviest amounts east of
Denali Park. This rain could cause rapid rises on streams and
small rivers in steep terrain. People in the Alaska Range east of
Denali Park, and along the Goodpaster, Charlie and Fortymile
Rivers should be alert to the possibility of heavy rain and
rapidly rising streams and rivers tonight through Thursday.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Brisk Wind Advisory for PKZ814.
     Brisk Wind Advisory for PKZ815.
     Small Craft Advisory for PKZ858.
     Brisk Wind Advisory for PKZ860.
&&

$$

JB