Weather Service Report


396 
FXAK69 PAFG 302153
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
153 PM AKDT THU JUN 30 2016

.SYNOPSIS...
Aloft...
A ridge of high pressure that stretches from NW Canada west
across Northern Alaska will slowly weaken through the weekend but
persist into next week. A low in the Gulf of Alaska will will
drift slowly east on the weekend. A series of short wave troughs
spinning NW from this low will move west across the Alaska Range
and Interior Alaska through the weekend. Bands of showers and
thunderstorms associated with these troughs will move west across
the southern Interior and Alaska Range through the weekend. The
highest moisture levels and strongest instability will be across
the Alaska Range and southern Interior and those areas will see
significant rain through the weekend. The heaviest rain will be in
SE interior and Alaska Range SE of Eagle to Big Delta to
Minchumina. Temperatures will remain near to just above normal
through the weekend.

A weak short wave trough from Mcgrath to Galena will move to
Bethel to Anvik late tonight. Scattered Thunderstorms with
frequent lighting and small hail are occuring along this trough
and will continue through tonight.

A second short wave trough from Beaver Creek to Eagle will move to
Denali to Coldfoot by 4am Fri and to McGrath to Huslia by 4pm Fri.
There are widespread showers and scattered thunderstorms that
will spread west with the trough through Fri. Showers will be
isolated to scattered over the northern Interior.

A third and stronger short wave trough over the southern Yukon
Territory will move to Glennallen to Northway by 4am Fri...to
Denali to Old Crow by 4pm Fri...to McGrath to Old Crow by 4am Sat
and to Telida to Fort Yukon by 4pm Sat. There will be heavy
showers with this trough across the southern Interior and Alaska
Range with isolated to scattered showers to the north.

A fourth short wave will rotate NE to the SE Interior and SE
Alaska Range on Sat and then persist through Sun. This will cause
more widespread showers over the SE Interior and SE Alaska Range
Sat into Sun.

Surface...
An Arctic front from Barter Island to Barrow will move to Barter
Island to Deadhorse north by 4pm Fri and then moving north of the
coast Sat. A 1025 mb high north of the eastern Arctic Coast will
move east over Banks Island Fri. Will see stratus and fog along
the Arctic front move north of the coast as the front moves north.

A 1020 mb high over the northern Bering Sea will persist through
Sat. This will cause winds to be NW along the West Coast of Alaska 
and cause areas of stratus and fog over the southern Chukchi Sea
and the Bering Strait and St Lawrence Island through Sat.

&&

.DISCUSSION...
Models similar solutions at 500 mb through the weekend. Slight
differences in speed and location of short wave trough leads to
significant differences in location and amounts of precipitation
through the weekend. We went along with the GFS but smoothed out
the precipitation amounts with the NAM and EMCF. All models show
the heaviest rainfall tonight and Fri in the Alaska Range and that
makes the most sense at this point. There may be heavier rain
north of the Alaska Range but due to the convective nature it
cannot be pinpointed until convection occurs.

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

&&

.FIRE WEATHER...
Significant number of lighting strikes occuring today across the
southern Interior. In the southern Interior RH will remain above
30% with significant rain. In the northern Interior Rh will drop
below 30% on the weekend with temperatures reaching near 80.

&&

.HYDROLOGY...
1 to 2 inches of rain likely through Fri southeast of Eagle to
Minchumina with the heaviest amounts in the Alaska Range with the
heaviest rain tonight and Fri. At this time it looks like most of
that area will get 1 to 2 inches of rain through Fri...but in the
Alaska Range a few locations could get as much as 3 inches. The
locations of the higher amounts is very uncertain due to the
convective nature of these events and rainfall amounts will need
to be watched closely. At this time no flooding is expected...but
small streams in the Alaska Range are expected to rise rapidly on
Fri with mudslides possible along steep slopes. Larger rivers
across the southeast Interior and Alaska Range will be rising
through the weekend as well.

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


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory for PKZ240-PKZ245.
&&

$$

JB JUN 16

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Western Regional Climate Center, wrcc@dri.edu