Small Craft Advisory 92, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
319 PM AKDT MON JUL 25 2016

.SYNOPSIS...
Aloft...
There is currently a low over the Gulf of Alaska and over the high
Arctic with a weak ridge over the West Coast and Interior of
Alaska. Several short wave troughs will move from north of Siberia
southeast across the Chukchi Sea and West Coast of Alaska this
week causing the lows to merge into a long wave trough over
mainland Alaska by late this week and then persisting into next
week. This will bring about a cooling and wetting trend late this
week that will persist into next week.

A weak short wave trough from Cape Lisburne to the Chukotsk
Peninsula will move to Deadhorse to Nome by 4am Tue...and to
Barter Island to Norton Sound by 4pm Tue and then dissipating
over the eastern Interior Wed. With this feature expect some low
to mid level clouds along with drizzle and fog along the coast and
just mid level clouds inland. Expect a few afternoon thunderstorms
with this feature over Interior Tue and Wed.

A second and stronger short wave will move over the western
Chukchi Sea by 4pm Tue, to Cape Lisburne to the Yukon Delta by
4am Wed, to Barrow to Bethel by 4pm Wed...and then dissipating
over the eastern Interior Thu. There will be rain with this
feature along the NW Coast of Alaska that will become scattered
showers as it moves southeast across mainland Alaska. Isolated
thunderstorms will form along and east of this feature Wed and
Thu.

A third short wave will move to the Chukchi Sea Wed pm and to the
western Interior and western North Slope Thu. This will bring
widespread rain to the western North Slope and West Coast Wed
night and Thu with numerous showers and isolated thunderstorms in
the central and western Interior Thu.

Surface...
A thermal trough from McGrath to Chicken will move to Anvik to
Fairbanks to Eagle by 4pm Tue and to Bethel to Tanana to Old Crow
by 4pm Wed. There could be a few thunderstorms along and south of
the today and Tue, becoming isolated Wed and Thu along and south
of the trough.

A low in eastern Siberia will move to south of Wrangel Island as
a 1004 mb low by 4am Tue, to 100 NM west of Cape Lisburne by 4pm
Tue as a 1001 mb low, to near Point Lay as a 999 mb low by 4am
Wed, to 150 nm north of Barrow as a 997 mb low by 4pm Wed, and
then continue moving north. A cold front trailing this low will
move to Point Lay to the Bering Strait by 4am Wed, to Nuiqsut to
the Bering Strait by 4pm Wed, and to Deadhorse to Norton Sound by
4pm Thu. Will see widespread rain with the low center.

&&

.DISCUSSION...
Models showing similar long wave pattern through Fri then start
to see large differences on timing and strength of short waves
over the weekend. Will use the ECMF ensemble means from the
weekend into next week per WPC discussion. At the surface the
the NAM and GFS differ significantly on strength of surface low
moving east across the southern Chukchi Sea on Tue. The NAM
deepens the low too much as it moves over the water so prefer the
GFS solution which maintains the low without deepening it.

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

&&

.FIRE WEATHER...
a few thunderstorms possible today and Tue in the southern
Interior, Isolated thunderstorms possible Wed and Thu south of the
thermal trough. Rh will remain above 30%.

&&

.HYDROLOGY...
Chena River will remain high through Wed with minor flooding
upstream of Nordale Road including the Steamboat Landing
subdivision.
The Tanana River will fall slowly next several days with ponded
water slowly receding.
Lake Minchumina will remain high and possibly rise through the
week.
Small Rivers in the Alaska Range near Isabell Pass will remain
high today then fall tonight.
There is a possibility of heavy rain in western Alaska Range from
Denali southwest on the weekend that will need to be monitored but
is still very uncertain at this point in time.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Flood Advisory for the Chena River upstream of Nordale Road including
the Steamboat Landing Subdivision.
Small Craft Advisory for PKZ235

&&

JB JUL 16