726
FXAK69 PAFG 211450
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
650 AM AKDT Fri Jun 21 2024



.SYNOPSIS...
A thermal low pressure trough stretching from Eagle to Tanana to
Point Hope will move to Chicken to Nenana to Point Hope by 4pm
Fri, and to Northway to Denali to Point Hope by 4am Sat, and to
Northway to McGrath to Anaktuvuk Pass to Point Hope by 4pm Sat and
remain there into Sun. A second thermal trough from Tanana to
McGrath will move to Nenana to McGrath by 4pm Fri, and then to
Denali south by 4am Sat. The thermal troughs will serve as focus
mechanisms for convection through Sat. Expect isolated to
scattered showers along the troughs with isolated thunderstorms.
Expect widely scattered thunderstorms in the afternoon/evening
today along the Alaska Range and over the Western/Central Interior
and over the Western Interior on Sat.

Today is expected to be slightly warmer and drier in most areas,
except the Southeast Interior and Southwest Interior which can
expect scattered to numerous showers today into tonight. A drying
and warming trend will occur across the Interior through the
weekend. Next week hot and dry conditions are expected over the
Interior.

From Fairbanks northeast, northeast winds will blow at 10 mph
this afternoon into Sat, and combined with temperatures in
upper 70s and lowers 80s, and RH near 25%, will bring near
Red Flag conditions to the Interior from Fairbanks northeast this
afternoon and evening and Sat afternoon/evening. These winds will
also push smoke southwest of the Richardson Highway this afternoon
with smoke remaining southwest of the Richardson Highway through
Sat night.

High pressure north of the Arctic Coast is expected to push
stratus clouds and fog along the coast today, with the stratus
and fog remaining there through the weekend.

High pressure building over the Chukchi Sea and Eastern Bering Sea
through tonight is expected to cause stratus and fog to form over
those areas today and tonight, and to push into the West Coast
tonight and then remain along the West Coast through the weekend,
although burning off along the coast during the PM each day.

&&

.DISCUSSION...
Models initialize well aloft at 00Z and show similar conditions
aloft through Sun, with slight differences developing next week.
Will use a blend of models for features aloft through the
weekend.

The strong ridge aloft stretching from NW Canada across Northern
AK to the Chukchi Sea will build slightly through Sat, then weaken
slightly on Sun as a strong low aloft over the Arctic Ocean
approaches the North Slope. Heights aloft will build over the
Interior next week leading to a return to hot and dry conditions
over the Interior, while the coasts remain close to normal
temperatures.

A weak short wave trough over the YK Delta will remain stationary
today, then drift east over the SW Interior tonight and Sat, then
strengthen on Sun as more short wave energy feeds into it from the
west. This will cause scattered showers and isolated thunderstorms
today that will move over the Western Interior tonight and Sat,
with isolated to scattered showers and isolated PM thunderstorms
over the Western and Central Interior on Sun.

A second weak short wave trough over the SE Interior will weaken
slowly in place through Sat. This is causing scattered showers
and isolated thunderstorms over the SE Interior that will increase
to scattered to numerous showers and Isolated to widely scattered
thunderstorms this PM, then taper off to isolated showers after
midnight tonight, with scattered showers and isolated PM thunderstorms
over the SE Interior on Sat, then few if any showers over the
Eastern Interior on Sun. Could see another 0.25-0.50 inch of rain
in the SE Interior through tonight.

At 850 mb, temperatures warm 1-2C today compared to Thu, then
warm another 1-2C over the weekend. This will cause today to be
slightly warmer than Thu in most areas, with a warming and drying
trend most areas over the weekend.

At the surface at 06Z, models all verify 2-3 mb too weak on the
High north of the Arctic Coast, 4-6mb too weak on the low over the
Gulf of AK, and the NAM and GFS are 2-3 mb too strong on the
thermal low over the Southern Yukon Territory while the ECMWF and
Canadian models verify well on those features. With the stronger
than forecast gradient across AK, expect slightly stronger winds
than models indicate through Brooks Range Passes and along the
West Coast through at least tonight. Will use a blend of models
for surface features and winds through Sun, but boost up winds
3-5 kt above models through Brooks Range Passes and along the West
Coast today through Sat. Expect north winds 15 mph gusting to 25
mph through Brooks Range passes through tonight, otherwise winds
in the Interior should remain below 15 mph through Sun. Along the
West Coast and Western Arctic Coast expect winds up to 20 mph but
not greater through Sun.

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

&&

.FIRE WEATHER...
A thermal low pressure trough stretching from Eagle to Tanana to
Point Hope will move to Chicken to Nenana to Point Hope by 4pm
Fri, and to Northway to Denali to Point Hope by 4am Sat, and to
Northway to McGrath to Anaktuvuk Pass to Point Hope by 4pm Sat and
remain there into Sun. A second thermal trough from Tanana to
McGrath will move to Nenana to McGrath by 4pm Fri, and then to
Denali south by 4am Sat. The thermal troughs will serve as focus
mechanisms for convection through Sat. Expect isolated to
scattered showers along the troughs with isolated thunderstorms.
Expect widely scattered thunderstorms in the afternoon/evening
today along the Alaska Range and over the Western/Central Interior
and over the Western Interior on Sat.

Today is expected to be slightly warmer and drier in most areas,
except the Southeast Interior and Southwest Interior which can
expect wetting rains today into tonight. A drying and warming
trend will occur across the Interior through the weekend.
Next week hot and dry conditions are expected over the Interior.

From Fairbanks northeast, northeast winds will blow at 10 mph
this afternoon into Sat, and combined with temperatures in
upper 70s and lowers 80s, and RH near 25%, will bring near
Red Flag conditions to the Interior from Fairbanks northeast this
afternoon and evening and Sat afternoon/evening.

&&

.HYDROLOGY...
Could see another 0.25-0.50 inch of rain the SE Interior through
tonight, which is in additional to the 0.25-0.50 inch seen in
that same area in the past 24hrs. This will lead to rises on
creeks and rivers in the Alaska Range east of Denali and in the
Upper Charlie and Upper Fortymile Rivers today and Sat.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Dense Smoke Advisory for AKZ839-840.
PK...Small Craft Advisory for PKZ812.
     Small Craft Advisory for PKZ858.
&&

$$

JB