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FXAK69 PAFG 221528 AAA
AFDAFG

Northern Alaska Forecast Discussion...UPDATED
National Weather Service Fairbanks AK
728 AM AKDT Sat Jun 22 2024

.SYNOPSIS...
Strong high pressure in the upper atmosphere over Northern Alaska
will move slightly south on Sun, then build back north on Mon and
continue to build through next week. This means that there will
be just slight warming in temperatures most areas through the
weekend as skies become more sunny, with more of an increase in
temperatures Mon. This should also result in decreasing moisture
and decreasing number of thunderstorms and showers today into
Sun.

A thermal low pressure trough stretching from Northway to Tanana
to Point Hope will move to Northway to McGrath to Anaktuvuk Pass
by 4pm today, with a another trough forming along the Brooks
Range. This thermal trough will remain in place through Sun and
then become a more diffuse trough over the Eastern Interior on
Mon. This will trough will server as a focus for convection.

There will be isolated to scattered showers and isolated PM
thunderstorms over the SE Interior and over the Brooks Range today
that will diminish to isolated PM thunderstorms in those areas on
Sun.

Scattered to numerous showers over SW AK and Norton Sound will
move east over the Western Interior today along with isolated
thunderstorms, and widely scattered PM thunderstorms. Expect
showers in the same areas on Sun but with with lower areal
coverage along with warmer temps and drier conditions.

Surface high pressure north of the Arctic Coast will persist
through Mon. High pressure building west of the West Coast of AK
will persist into Mon. These features will cause the Arctic Coast
and West Coast to have stratus and fog move onshore later today
and thicken tonight, with the stratus and fog continuing into next
week. Fog should thing each afternoon as it burns off from the
inland areas each day.

By Monday conditions will be warmer and drier in most areas with
just isolated showers over the Brooks Range.

Beyond Monday, the Interior and North SLope will warm to much
above normal next week with mainly dry conditions, while the West
Coast will cool to normal and become wetter.


.DISCUSSION...
At 00Z, models all initialize 10 to 20 meters too low on the 500
mb ridge centered over Northern AK, except that the ECMWF
initializes very well. Models show similar solutions aloft
through Mon except that the ECMWF keeps heights slightly higher
than other models, and the ECMWF weaken the short wave over SW
more quickly tonight and Sun than other models.

This means that the upper level pattern should consist of a strong
ridge centered over Northern AK that will drift south over
Southern AK by Sun with slightly lower 500 mb heights over
Northern AK on Sun, then build over all of AK on Mon and then
continue building into Tue. Expect this to mean that there will be
just slight warming in temperatures most areas through the
weekend as skies become more sunny, with more of an increase in
temperatures Mon. This should also result in decreasing moisture
and convection and showers today into Sun, with little if any
convection and drier conditions by Mon.

A weak short wave trough over the SE Interior will weaken slowly
through Sun. This will cause isolated to scattered showers and
isolated PM thunderstorms over the SE Interior today, with
isolated PM thunderstorms on Sun.

A stronger short wave trough from Nome to Bethel will move to
Golovin to Sleetmute by 4pm Sat, to Galena to McGrath by 4am Sun,
then weaken and move to Anaktuvuk to McGrath by 4pm Sun, then
dissipating Sun night. This will cause scattered to numerous
showers over SW AK and Norton sound to move east over the Western
Interior today with Isolated thunderstorms, and widely scattered
thunderstorms in the PM, then just isolated showers and isolated
PM thunderstorms from McGrath to Anaktuvuk Pass on Sun.

Beyond Mon, all models build the ridge over NW Canada and Eastern
AK strongly through next week, but they do differ on how close
lows move into the West Coast next week. What this means is that
the Interior and much of the North Slope will warm to much above
normal next week and be mainly dry, while the West Coast will cool
to be near normal and wet.

With precipitation, models show similar areas for coverage by
showers through Mon, but differ in pops and amounts. The main
thing to show is trending to drier conditions most areas through
Sun, with little if any showers on Mon. Expect scattered to
numerous showers over SW AK and Norton Sound moving east over the
Western Interior today with Isolated thunderstorms, and widely
scattered thunderstorms in the PM. The Eastern Interior will be
mainly dry with isolated to scattered showers and isolated PM
thunderstorms over the SE Interior and over the Brooks Range
today. Expect showers in the same areas on Sun but lower in areal
coverage. By Mon just isolated showers along the Brooks Range.

At the surface at 06Z, models verify well on most features except
that they are all 8 MB too weak on the low in the Gulf of AK.
Since the gradient between the Arctic Coast and the Interior is
well modeled, expect models winds to perform well in most areas.
The exception is the AK Range where north winds will be stronger
than models indicate through passes, but this will mainly affect
areas on the south side of the AK Range. Expect winds to remain
less than 15 mph over the Interior through Mon, except for north
winds 15 mph gusting 25 mph today through Brooks Range and Alaska
Range Passes. The coasts should see winds less than 20 mph
through Mon.

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

&&

.FIRE WEATHER...
There will be slight warming in temperatures in most areas
through the weekend as skies become more sunny, with more of an
increase in temperatures on Mon. This should also result in
decreasing moisture, and a decrease in convection and showers
today into Sun, with little if any convection and drier conditions
by Mon. There will be isolated to scattered showers and isolated
PM thunderstorms over the SE Interior and over the Brooks Range
today that will diminish to isolated PM thunderstorms in those
areas on Sun. Scattered to numerous showers over SW AK and Norton
Sound will move east over the Western Interior today along with
isolated thunderstorms, and widely scattered thunderstorms in the
PM. Expect showers in the same areas on Sun but lower in areal
coverage and warmer temps and drier conditions.

By Mon conditions will be warmer and drier with just isolated
showers along the Brooks Range.

Beyond Mon, the Interior will warm to much above normal next week
and be mainly dry, while the West Coast will cool to near normal
and become wetter.

&&

.HYDROLOGY...
The Fortymile River is rising today and will start falling next
week. Most other clear water rivers will fall this weekend into
next week as conditions dry, but glacial fed rivers will rise
steadily through the next week due to warming temperatures and
increased high elevation snow melt.


FAREWELL...
This forecaster is retiring after 37 years forecasting in Alaska,
and this is their last official forecast. It has been their great
pleasure to work for the NWS and serve the people of Alaska.
There is a strong team of forecasters in Fairbanks that will do
a great job carrying out the NWS mission of protection of life
and property in the future. Farewell.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...None.
&&

$$

JB