411
FXAK69 PAFG 272255
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
255 PM AKDT Thu Jun 27 2024

.SYNOPSIS...
Today looks like it is going to end up as one of the most impactful
weather days of the Summer. Hot and dry conditions will persist
across the Interior and North Slope with even some windy areas in
the northern Interior. Areas of dense smoke from fires burning is
reducing visibilities along portions of the Elliott, Steese, and
Richardson Highways. Scattered thunderstorms are occurring from
the Western Brooks Range to Fairbanks to the Alcan Border, with
strong thunderstorms continuing overnight on the North Slope.
Isolated dry thunderstorms are occurring from Central north to
Fort Yukon. Southeast winds 15 to 25 mph will persist on the west
coast south of Nome bringing elevated water 1 to 2 feet above the
normal high tide line south of the Bering Strait through Friday.

&&

.DISCUSSION...

Analysis and Model Discussion...

A strong ridge of high pressure aloft remains over the eastern
half of Alaska, & the center has shifted northward to be over the
eastern North Slope. The ridge has weakened slightly today with
temperatures remaining warm to downright hot in some areas. A
strong vertically stacked low will remain in the central Bering Sea.
A number of shortwaves are moving through the convergence zone
between the low and the ridge this afternoon bringing scattered
thunderstorms from the western North Slope SE to Tanana.
Another shortwave is rotating around the high center to provide
the forcing for scattered thunderstorms over the central and
eastern Interior south of the White Mountains. Isolated dry
thunderstorms are occurring from Central north to Fort Yukon.
Fortunately, LCLs are substantially lower with more influence from the
Gulf of Alaska tomorrow over the Upper Tanana Valley and storms
there and across the rest of the area should be wet. Perhaps the
most intriguing development in the forecast is the likelihood of
very strong thunderstorms on the North Slope this afternoon
through Friday afternoon. Models continue to indicate areas of
CAPE >1000 J/kg with Lifted Indices as low as -4. we have issued a
Special Weather Statement for this. This is all associated with
both shortwaves moving through the convergence zone and the
shortwave moving around the high to the east. Storms will likely
continue all night Thursday night into Friday and may reach the
coast. These storms may produce hail up to half an inch in
diameter and outflow winds as high as 40 mph.

On Friday, the focus of convection in the Interior shifts to the
Yukon Flats as a shortwave aloft from the south moves over that
area off the high center. Temperatures will be 3 to 5 degrees
cooler than today except in the Yukon Flats, though temperatures
look to warm back up on Saturday. Convection on Saturday looks
to just be isolated over the eastern Interior but widely scattered
right along the Alcan Border and in the SE Brooks Range.

Models initialized very well with respect to observations aloft
and at the surface, however the HRRR smoke model continues to
struggle, still showing very dense smoke over the Fairbanks area
despite much of it being cleared out already Forecast models show
above average agreement aloft through Sunday morning and few
differences at the surface and in precipitation fields.

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

&&

.FIRE WEATHER...

Red Flag Warnings are in effect for hot, dry, and windy conditions
today across the northern Interior, and for lightning across the
Central and Eastern Interior. Sustained winds are around 10-15
mph in the Northern Interior, but thunderstorms will cause
erratic wind gusts. A ridge of high pressure in the Interior and
a trough of low pressure in the Bering Sea has created a boundary
from the NW Arctic to the SE Interior where strong, scattered
thunderstorms are happening this afternoon. Most of these
thunderstorms are wet, however widely scattered to isolated
dry thunderstorms are also happening from Central to Fort Yukon.
Today is expected to be one of the biggest thunderstorm days of the
summer across northern Alaska, once it is all said and done, with
some strong storms even happening from time to time on the North
Slope.

On Friday, a Red Flag Warning is in effect for lightning for the
Yukon Flats and SE Brooks Range where we expect scattered wet
thunderstorms, though an isolated dry storm is possible.
Temperatures will cool only slightly and RHs will moderate.

On Saturday, the thunderstorm threat moves to the AlCan border
and remains in the Eastern Brooks Range. For now, widely scattered
wet thunderstorms are expected.

&&

.HYDROLOGY...
Glacial fed rivers including the Tanana are beginning to rise as
warming temperatures lead to increased high elevation snowmelt.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Red Flag Warning for AKZ911-933.
     Red Flag Warning for AKZ912-913-919-931>935-939-943-944-946.
     Dense Smoke Advisory for AKZ834.
     Dense Smoke Advisory for AKZ839-840-844-845.
PK...Small Craft Advisory for PKZ801-802-850-851.
     Small Craft Advisory for PKZ816.
&&

$$