Severe Thunderstorm Warning 4, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
355 PM AKDT Sun Jul 10 2022

.SYNOPSIS...
Warm and smokey with isolated to scattered thunderstorms are
expected across the Interior and North Slope again today, with
thunderstorms confined to the Central and Eastern Interior
on Mon, and to the Eastern Interior from Fairbanks east on Tue.
The most significant thunderstorms with frequent lightning, hail
and gusty winds will be in the afternoon/evening southeast of
Tanana to Old Crow today and Mon. Wed will just see isolated
thunderstorms along the ALCAN Border.

Periods of heavy showers over the Southeast Interior today through
early Tue will drop significant rain southeast of Eagle to
Kantishna, with up to 1.5 inches along the Alaska Range. This
will cause water to rise on all rivers in the southeast Interior
this week, and will cause an increased risk of flooding of low
lying areas along the Tanana River such as the Tetlin Road, and
the Rosie Creek area near Fairbanks starting early this week.

A cold front over Eastern Russia will move east to Utqiagvik to
the Bering Strait on Mon, to the Central Arctic to the the YK
Delta by Tue afternoon, and to near the ALCAN Border by Wed
afternoon. Will see light rain and Northwest winds 10-15 mph with
the front, followed by cooler conditions behind the front. Expect
cooler than normal conditions and little if any lightning after
from Wed night through next weekend.

Aloft...
A ridge aloft stretching from SW Alaska to NE Alaska into NW
Canada will weaken slowly over the next several days. A low aloft
over NE Russia and over the Gulf of AK will gradually merge over
the next several days so that there is a long wave trough over
Alaska by Wed that will persist into the weekend.

A short wave trough from Tok to Eagle will move to Denali to
Circle late tonight. This is causing significant thunderstorm,
some of which may contain large hail, as it moves west this
evening. This are will need to be watched all evening. One severe
thunderstorm with large hail just occurred near Quartz Lake.

A strong short wave over eastern Russia will move over the West
Coast of Alaska Mon, over the Western Interior on Tue, and over
the Eastern Interior on Tue. This will push a strong cold front
east.

Surface...
A thermal trough stretching from McGrath to Livengood to Eagle
will persist into Mon and then move east on Tue. A warm and
unstable airmass associated with this will cause isolated to
scattered thunderstorms across the Interior. Scattered
thunderstorms (some with hail, gusty winds, and frequent
lightning) will occur in the afternoon and evening today and
Monday over the area southeast of Tanana to Old Crow. Expect
around 5000 lightning strokes today. Similar conditions
are expected again Mon, and again around 5000 lightning
strokes. Thunderstorms should taper off from the west Tue and Wed.

A 998 mb low 300 NM north of Wrangel Island will move to 600 NM
north of Demarcation Point by 4pm Mon as a 990 mb low, and then
continue moving northeast. A cold front trailing from this low
south along the Dateline will move to Utqiagvik to the Bering
Strait by 4pm Mon, and to Prudhoe Bay to the YK Delta by 4pm Tue,
and to near the ALCAN Border by Wed afternoon. Will see light
rain and Northwest winds 10-15 mph with the front, followed by
cooler conditions behind the front. Expect cooler than normal
conditions and little if any lightning after from Wed night
through next weekend.

&&

.DISCUSSION...
Models initialize well aloft at 12Z and show similar solutions
aloft through Wed. At lower levels, (700mb, 850mb and the surface)
the GFS and ECMWF are slower than the NAM and Canadian with the
eastward movement of the cold front across the Interior Tue and
Wed. Since short wave energy supporting the cold front drops south
over the Bering Sea on Mon and then moves over the AKPEN and Gulf
of AK on Tue and Wed, where it energizes a surface feature, which
in turn causes an increased southeast flow over SW AK and slows
the frontal movement across the southern Interior on Tue. For
these reasons we prefer the slower frontal movement shown by the
GFS.

With precipitation, the NAM show too much precipitation, and too
far south of where it is occuring this morning, whereas the GFS
and ECMWF are better in the location. By this afternoon models are
in better agreement, on location of precip, but differ
significantly in location of heavier amounts. On thing models do
agree on is that there will be significant precip south of Eagle
to Kantishna through 4am Tue, with the heaviest along the Alaska
Range. Given the convective nature, and the NE steering flow
which will cause upslope along the north side of the Alaska Range
this makes sense. Once the north-northeast flow drops off Tue the
heavier precip will end.

For convection, today will be similar to Sat, with isolated
thunderstorms over most of the Interior and North Slope, and
scattered thunderstorms (some with hail, gusty winds, and frequent
lightning) over the area southeast of Tanana to Old Crow. Can
expect around 5000 lightning strokes today. Similar conditions
are expected again Mon, but with few thunderstorms over the
Western Interior or North Slope, and again around 5000 lightning
strokes. For Tue expect isolated thunderstorms east of Denali to
Chandalar Lake with widely scattered thunderstorms near the ALCAN
Border. Wed should see between 1000-3000 lightning strokes.

At the surface at 15Z, modes verify well on most features over
AK, but are all 3 mb too weak on the surface lows over and north
of Eastern Russia. Since those lows move to the north and south of
Alaska, dont expect this to matter much. Models show similar
solutions at the surface through 4pm Mon, then the NAM and
Canadian are faster in the eastward movement of the cold front
across the Interior. As mentioned in the discussion of model
features aloft, we prefer the slower GFS solution at the surface.

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

&&

.FIRE WEATHER...
For convection, today will be similar to Sat, with isolated
thunderstorms over most of the Interior and North Slope, and
scattered thunderstorms (some with hail, gusty winds, and frequent
lightning) over the area southeast of Tanana to Old Crow. Can
expect around 5000 lightning strokes today. Similar conditions
are expected again Mon, but with few thunderstorms over the
Western Interior or North Slope, and again around 5000 lightning
strokes. For Tue expect isolated thunderstorms east of Denali to
Chandalar Lake with widely scattered thunderstorms near the ALCAN
Border. Tue should see between 1000-3000 lightning strokes.
We will see isolated thunderstorms just along the ALCAN Border
with just a few hundred strokes.

Periods of heavy showers over the Southeast Interior today through
early Tue will drop significant rain southeast of Eagle to
Kantishna, with up to 1.5 inches along the Alaska Range.

A cold front over Eastern Russia will move east over the Western
INterior Tue afternoon, and to near the ALCAN Border by Wed
afternoon. Will see light rain and northwest winds 10-15 mph with
the front, followed by cooler conditions behind the front. Expect
cooler than normal conditions and little if any lightning after
from Wed night through next weekend.

&&

.HYDROLOGY...
Glacial rivers draining the Alaska Range such as the Tanana,
Chisana, and Nabesna Rivers are running near bankfull. This is due
to hot temperatures causing significant high elevation snow melt
in the Alaska Range.

Periods of heavy showers over the Southeast Interior today through
early Tuesday will drop significant rain southeast of Eagle to
Kantishna, with up to 1.5 inches along the Alaska Range. This
will cause water to rise on all rivers in the southeast Interior
this week.

The Tanana River will have an increased risk of flooding of low
lying areas starting Tuesday. People in the Rosie Creek
Subdivision near Fairbanks, and people traveling the Tetlin Road
should prepare for potential flooding this week.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning for AKZ220-AKZ221-AKZ222-AKZ223-AKZ224.

Dense Smoke Advisory for AKZ221-AKZ222.
&&

JB JUL 22

Special Weather Statement
National Weather Service Fairbanks AK
343 PM AKDT Sun Jul 10 2022

AKZ221>224-226-120030-
Central Interior-Middle Tanana Valley-Deltana and Tanana Flats-
Upper Tanana Valley and the Fortymile Country-
Eastern Alaska Range-
Including Nenana, Anderson, Tanana, Minto, Manley Hot Springs,
Rampart, Lake Minchumina, Livengood, Fairbanks, Fort Wainwright,
Eielson AFB, Ester, North Pole, Moose Creek, Two Rivers, Fox,
Chatanika, Chena Hot Springs, Sourdough Camp, Salcha,
Delta Junction, Fort Greely, Harding/Birch Lake, Dry Creek,
Dot Lake, Healy Lake, Tok, Tanacross, Eagle, Tetlin, Northway,
Alcan, Chicken, Boundary, Black Rapids, Donnelly Dome,
Trims DOT Camp, Eagle Trail, and Mineral Lake
343 PM AKDT Sun Jul 10 2022

...Flooding Possible on the Tanana River Starting Monday...

Glacial rivers draining the Alaska Range such as the Tanana,
Chisana, and Nabesna Rivers are running near bankfull. This is due
to hot temperatures causing significant high elevation snow melt
in the Alaska Range.

Periods of heavy showers over the Southeast Interior today through
early Tuesday will drop significant rain southeast of Eagle to
Kantishna, with up to 1.5 inches along the Alaska Range. This
will cause water to rise on all rivers in the southeast Interior
this week.

The Tanana River will have an increased risk of flooding of low
lying areas starting Tuesday. People in the Rosie Creek
Subdivision near Fairbanks, and people traveling the Tetlin Road
should prepare for potential flooding this week.

For the latest river information go to www.weather.gov/aprfc.

JB