Area Forecast Discussion
Issued by NWS Fairbanks, AK
FXAK69 PAFG 282300
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
300 PM AKDT THU JUL 28 2016
The main forecast concerns for northern alaska remain the potential
for widespread heavy rains over Western Alaska as well as the
Interior. The 28/12Z deterministic models are in fair agreement
through late Sunday with increasing spread among model solutions
The main feature of concern for the forecast period will revolve
around a deep upper low roughly 450 miles north of Wrangell
Island. Cyclonic flow will continue to increase over the area as
the low moves southeast towards and associated upper level trough
swings southeast. A shortwave and associated surface cold front
stretching from Prudhoe Bay to McGrath will continue to move east
this evening and tonight. A strong, vigorous shortwave and
surface cold front stretching from the Arctic to the Yukon Delta
will swing south and east Friday and Saturday. The southern extent
of this shortwave will break off and deepen into a closed low late
Sunday over the Kuskokwim Delta and Bristol Bay region.
West Coast and Western Interior...Showers will continue ahead and
along a southeastward moving cold front this evening and tonight
over the Lower and Middle Yukon and Upper Kuskokwim Valleys. As the
flow become westerly early Friday with the next shortwave,
deep layer moisture will stream across the Seward Peninsula and
Nulato Hills bringing 1 to 2 inches of rainfall Friday and
Saturday. Recurrence intervals for forecast precipitation (1 to 2
inches or more in a 24 hour period) over the Seward Peninsula are
in the 5 to 10 year range, but near Koyuk and in the upslope areas
of the western facing slopes of the Nulato Hills, the return
interval for forecast rainfall is at 25 years. A flood watch
remains in effect for zones 210, 211, 212, and 216. Since the
heavy rainfall was no longer forecast for zone 213, the flood
watch was cancelled.
Central and Eastern Interior...The transition to a wet, cool,
unsettled pattern is underway. A cold front is currently moving
southeast and will be the focus for late afternoon and evening
isolated thunderstorms. As the flow become west to southwesterly,
deep layer moisture will flow into the Central and Eastern
Interior as well as to the Alaska Range Friday bringing
widespread heavy rains with 1" to 1.5" rainfall accumulations.
Locally heavier rainfall amounts are expected in favored upslope
areas in the Interior and Alaska Range. Will have to continue to
monitor the need for headlines over the next few days, especially
over the Middle Tanana Valley where small streams and rivers are
still running high and soils are already saturated.
North Slope and Arctic Coast...A cooling trend is forecast as
H850 temperatures cool 10C over the next several days and will
range from -2C over the Brooks Range to -6C near Barrow Saturday
morning. Daytime temperatures will be in the 40s along the coast
and in the lower 50s inland with overnight lows bottoming out in
the 30s. There is a chance that snow may mix in with snow or may
completely change over to snow Friday night and Saturday as well
as Saturday night into Sunday at Barrow and in higher elevations
in the Brooks Range. Chances for precipitation will continue
through Saturday with up to a half inch of rainfall possible in
the upslope areas of the Brooks Range.
Coastal Hazard Potential Days 3 and 4...20 to 30 kt west to
southwest flow along the Yukon Delta coast as well as Norton
Sound will create the potential for elevated surf late Friday and
continuing through Saturday. At this point storm surge is expected
to be 1 to 3 feet above normal tides. Those with interests or with
personal property along the coast in Norton Sound and along the
Yukon Delta coast should move items above high water line.
Minimal fire weather concerns with expected widespread wetting
rains over much of the west coast, western and central interior
Friday and Saturday.
Storm total QPF through Saturday are in the 1 to 2 inch range
with locally higher amounts. Flood Watches in effect for zones
210, 211, 212, and 216. Will need to closely monitor potential
for heavy rains and need for additional headlines especially in
the western Alaska Range and the Interior especially with recent
rain events and rivers still running high.
Flood Advisory continues for the Chena River upstream of Nordale
Road, see latest statement for up to date information. Flow on the
Chena River through Fairbanks continues to be controlled to less
than 12,000 cfs by the Moose Creek Dam.
Flood Watch for AKZ210-AKZ211-AKZ212-AKZ216. Flood Advisory for
the Chena River upstream from Nordale Road.
LTH JUL 16