927
FXAK69 PAFG 300859
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
1259 AM AKDT Sun Jun 30 2024

.SYNOPSIS...
Another hot day for the Interior today as temps reach into the mid
80 degree range. Smoke will continue to be hazardous to health
across parts of the Interior with poor smoke ventilation rates.
Monday, the ridge is weakening and west winds begin to ventilate
smoke off to the east which should result in some improvement.
Tuesday, southwest winds increase even more and temps slowly begin
falling as a major pattern shift begins toward breezier, cooler,
and eventually wetter conditions.

&&

.DISCUSSION...

Upper Levels and Analysis...
There is a 538 dam upper low centered over the E Aleutian Islands
with a building 569 dam ridge over the Interior of Alaska and
poking into the NW Arctic. There is a 528 dam arctic low over the
Beaufort Sea. There is a broad 1006 mb thermal trough situated
over the SE Interior. Weak high pressure is over the Arctic coast
with areas of stratus and fog.

Model Discussion...
Models are locked into the general pattern well into late week. We
prefer a NAM nest hi-res winds forecast with a blend to the NAM
and GFS models for the beginning of next week as a strong trough
moves across the NW Arctic, bringing winds and cooler temps.

Central and Eastern Interior...
Another hot and smoky day for much of the Interior as temps shoot
into the mid to upper 80s. Isolated thunderstorms will be possible
from Fairbanks south and east, with strong thunderstorms expected
over parts of the Alaska Range and SE Interior from Northway to
Eagle. Showers and some isolated thunderstorms will likely go all
night long along and near the AK Range. Monday, a pattern shift
begins with slightly cooler temps and increasing west to southwest
winds over the Interior, which will support more afternoon
thunderstorm chances from Fairbanks south and east. With a weak
northwest steering flow, some thunderstorms will form over the
hills and drift into the Fairbanks area. The westerly winds will
begin to ventilate smoke out of the Interior and it should
improve air quality somewhat. Tuesday is cooler again with breezy
westerly winds to 10 to 15 mph and thunderstorm threats generally
relegated to the higher elevations and over the E Interior.

West Coast and Western Interior...
Slowly warming temps through Monday, with a fairly good chance for
some stronger thunderstorms and heavy rain showers late today and
tonight from the W Alaska Range west to the YK Delta, as an
easterly wave moves across that area. Some storms may get fairly
close to the coast by Sun night. Otherwise, Monday is fairly quiet
with some isolated thunderstorms over the Interior and some
southwest winds in the afternoon. Tuesday, a fairly stout mid-
summer front will bring in broad southwest winds to near gale
force and rain from the Seward Peninsula north, with heavy rain
over the W Brooks Range. Expect 1-3 inches of rainfall over the
Chukchi coastal region and higher elevations.

North Slope and Brooks Range...
Isolated thunderstorms are again possible Sunday mainly over the E
Brooks Range, with some showers on Monday over the crest of the
range. Otherwise, weak high pressure along the coast will promote
periods of sun and stratus/fog at times, although it will not be
extremely widespread. Beginning Tuesday, a strong front
originating from E Siberia will plow across the entire region
bringing heavy rainfall and strong southwest winds 15 to 30 mph
with higher mountain gap winds.

Extended Forecast Days 4-7...
The big shift in the pattern is commencing Tue and continuing
through late week, as subtropical zonal flow pushes the ridge east
and replaces it with strong southwest winds and periods of
rainfall for the later week. This pattern will be a huge shift
from the hot and dry and smoky and will likely bring relief to
the Interior.

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...
Hot and dry today with widely scattered to scattered thunderstorms
over the SE Interior, and isolated thunderstorms over the Interior
to Fairbanks and to the W Alaska Range. Temps are in the mid 80s
and min RH will be widespread mid to upper 20 % range. Winds will
be light from the north, so smoke will continue to be dense at
times. A batch of strong thunderstorms and wetting rains will
likely move across the W Alaska Range across the Kuskokwim Valley
and Kuskokwim Mtns to the Delta. The scattered thunderstorms over
the SE Interior are also very wet.

Monday, the flow becomes westerly near the surface with cooling
temps by 3 to 5 degrees and improving dense smoke conditions as
ventilation rates will increase. More afternoon isolated to widely
scattered thunder over the Interior higher elevation terrain, but
with a northwest steering flow, some storms will move south into
the Tanana Valley. Tuesday, southwest winds increase even more and
will get to near critical values over the N Interior, but will be
fairly breezy everywhere. Temps are falling again closer to
seasonal norms of mid to upper 70s. Only isolated thunderstorms
are expected Tue and those will favor higher elevations and the E
Interior. Wednesday will have fairly

&&

.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 -4 inches of rainfall through the
weekend, with 0.75 to 2 inches over parts of the Interior. Expect
river rises with this amount of water across the Mainland.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Dense Smoke Advisory for AKZ834-837-839>844.
PK...None.
&&

$$