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000
FXAK69 PAFG 191254
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
454 AM AKDT Mon Jul 19 2021

.SYNOPSIS...
A thermal low pressure trough stretching from Northway to Anvik
to Ambler will persist into tonight, then move to Barter Island
to Umiat to Livengood to Northway by 4pm Tue, and to Barter Island
to Northway by 4pm Wed. There will be isolated PM thunderstorms
near this thermal trough today through Wed, with widely scattered
thunderstorms possible along the Nulato Hills this afternoon/evening.
Expect temperatures in the 70s and lower 80s over most of the
Interior and North Slope today, over the Eastern Interior and
Eastern North Slope on Tue, and over the area from Fairbanks east
on Wed.

An occluded front in the Eastern Bering Sea will move northeast
into the West Coast and Western North Slope through tonight, and
into the Western Interior on Tue, into the Central Interior and
Central North Slope Tue night and Wed. This will bring a broad
area of rain to the YK Delta, the Western Seward Pen and Western
North Slope today, to the Areas from Anvik to Utqiagvik West
tonight, to the Areas from McGrath to Point Lay to Utqiagvik West
on Tue, and Denali to Tanana to Anaktuvuk Pass to Utqiagvik West
on Tue night, then diminishing to scattered showers in the same
area on Wed. Expect 0.25-1.00 inch of rain through Wed over the
West Coast, Western Interior and Western North Slope with the
heaviest amounts along south facing slopes.

Ahead of this front, will see weak chinook winds develop over the
Alaska Range tonight and continue through Wed. This will cause
south winds 15-25 mph through Alaska Range passes to develop
tonight and continue into Tue night then decreasing on Wed. Expect
RH to remain above 30% through Wed so below Red Flag criteria, but
will be near Red Flag for winds and temperatures near Delta
Junction on Tue.

Aloft...
The long wave pattern consists of a strong ridge over Mainland
Alaska, a trough over the Eastern Gulf of Alaska, and a second
trough over the Western Chukchi Sea and the Bering Sea. Several
strong short wave troughs will move northeast out of the Bering
Sea trough and dig into the ridge over the next several days. This
will cause the ridge to move east over the Far Eastern Interior
of Alaska and NW Canada by Wed with the trough over the West Coast
of Alaska. This pattern will then hold in place through the
weekend. This means that hot and dry conditions over much of
Northern Alaska will see a wetting and cooling from the west
through Wed, with the Eastern Interior and Eastern North Slope
remaining warmer and drier than normal through the weekend.

&&

.DISCUSSION...
Models initialize well aloft at 00Z. Models show similar
solutions aloft through Wed.

With precipitation, models show similar areal coverage and
amounts through 4pm Mon. For Mon night through Wed, the GFS and
ECMF are both a bit faster than the NAM bringing precip eastward
into the Interior. At this time, favor the faster GFS and EMCF
precip solutions.

At the surface at 06Z, models verify well over Alaska but all are
several mb too deep with a surface low in the Yukon Territory.
Models show similar solutions at the surface through 4pm Mon.
From Mon night into Wed the NAM and Canadian models deepen the
surface lows moving from the Bering Sea to the West Coast, while
the GFS and ECMF keep the surface lows strength about the same.
Since these features are well occluded as they move into the West
Coast, do not expect much deepening and so favor the GFS and ECMF
surface features and winds from Mon night into Wed.

Bottom line for models is that we will use a blend of models for
winds, temps, precip through 4pm Mon. From Mon night into Wed will
use a blend of the GFS and ECMF for winds, temps, precip amounts
and pops.

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

&&

.FIRE WEATHER...
A thermal low pressure trough stretching from Northway to Anvik
to Ambler will persist into tonight, then move to Barter Island
to Umiat to Livengood to Northway by 4pm Tue, and to Barter Island
to Northway by 4pm Wed. There will be isolated PM thunderstorms
near this thermal trough today through Wed, with widely scattered
thunderstorms possible along the Nulato Hills this afternoon/evening.
Expect temperatures in the 70s and lower 80s over most of the
Interior and North Slope today, over the Eastern Interior and
Eastern North Slope on Tue, and over the area from Fairbanks east
on Wed.

An occluded front in the Eastern Bering Sea will move northeast
into the Western Interior on Tue, into the Central Interior and
Central North Slope Tue night and Wed. This will bring a broad
area of rain to the YK Delta, the Western Seward Pen and Western
North Slope today, to the areas from McGrath to Point Lay to
Utqiagvik West on Tue, and Denali to Tanana to Anaktuvuk Pass to
Utqiagvik West on Tue night, then diminishing to scattered showers
in the same area on Wed.

Ahead of this front, will see weak chinook winds develop over the
Alaska Range tonight and continue through Wed. This will cause
south winds 15-25 mph through Alaska Range passes to develop
tonight and continue into Tue night then decreasing on Wed. Expect
RH to remain above 30% through Wed so below Red Flag criteria, but
will be near Red Flag for winds and temperatures near Delta
Junction on Tue.

&&

.HYDROLOGY...
Expect 0.25-1.00 inch of rain through Wed over the
West Coast, Western Interior and Western North Slope with the
heaviest amounts along south facing slopes. Expect to see rises on
all rivers in the Western Interior, West Coast and Western North
Slope from Tue through the end of the week. Do expect any
flooding.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

JB JUL 21