Small Craft Advisory 90, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
157 PM AKDT Sat Aug 11 2018

.DISCUSSION...

Synopsis...An overall pattern change is expected through the
weekend and into next week, as the remnants of Typhoon Shanshan
enter the forecast area Sunday through Tuesday. This will bring
increasingly wetter conditions across the West Coast and Western
Interior, with locally heavy rainfall possible for the
western Interior. Winds will strengthen across the West Coast and
portions of the Western Interior as well. Across the Alaska Range
strong southerly Chinook winds are expected to develop Sunday and
continue into Monday morning.

Aloft...Models in fairly good agreement through 84 hours.
A broad long wave trough remains over the Bering Sea today
containing a 540 dam center over the Gulf of Anadyr. A 588 dam
center of high pressure is over the North Pacific extending inland
over the Interior. The remnants of Shanshan will move into
Bristol Bay early Sunday morning as a 540 dam low. As the low
moves inland, the ridging over the North Pacific will deepen and
shift to the east as well. Shanshan low will weaken in place
over the western Interior on Monday. The entire state will remain
under a longwave trough through much of next week.

Surface...Remnants of Shanshan as a 978 mb low will
move into Bristol bay by 12Z Sunday then movenear Cape Newenham
as a 979 mb low by 00Z Monday, to a 986 mb low near Marshall by
12Z Monday, and continuing to weaken and slowly move eastward
Monday afternoon and Tuesday. As the remnants of Shanshan move
inland, leeside troughing will develop north of the Alaska Range
and deepen Sunday and Monday. A frontal boundary will stall out
over the Interior and continue to produce showers for the Interior
through Wednesday morning.

Arctic Coast and Brooks Range...Areas of fog and stratus will
continue along the eastern Arctic Coast. Shower activity this
morning from Barter Island east will taper off and drier
conditions are expected through Sunday. Afternoon temperatures in
the 40s along the coast today and Sunday, with highs in the 50s to
lower 60s inland. A weather front will move across the Arctic
Coast on Tuesday into Wednesday bringing a mix of rain and snow
showers to the north slope.

West Coast and Western Interior...Showers will become more
numerous going into Sunday and Monday as the remnants of Shanshan
move across. Moisture will surge across the coast, bringing
periods of heavy rainfall. Widespread rainfall accumulations of 1
inch likely, with isolated higher amounts in upslope areas. In
addition to the rainfall, strong and gusty winds are likely along
the coast and strong wind headlines will likely be needed. A Wind
Advisory has been issued for strong southeasterly winds in zone
227 on Sunday. Northerly winds will increase to 30 to 40 mph
during the afternoon on Sunday through the Bering Strait and push
water towards the north coast of St Lawrence Island. A high surf
advisory has been issued for zone 213 from Sunday afternoon
through Tuesday morning.

Central and Eastern Interior...As the remnants of Shanshan move
eastward, strong southerly Chinook winds are expected to develop
on Sunday for passes in the Alaska Range, continuing through
Monday morning. Have upgraded the high wind watches to warnings
for zones 223 225 and 226.  Strong southwesterly winds are
expected to develop west of Tok on Sunday as well. Rain chances
will increase for the region Sunday afternoon onward, but for
areas from Fairbanks south, rain chances will be a little more
limited due to downsloping. A steady warm up in temperatures is
expected across the Interior through Sunday as ridging aloft
builds across the area, with highs pushing into the upper 60s to
around 70 then cooling off again as showers become more widespread
on Tuesday.

Coastal Hazard Potential Days 3 and 4...
High surf advisory has been issued for zone 213 for northeast
facing coasts of St Lawrence Island, Little Diomede and Wales.
Waves and surf building to 8 to 12 feet offshore with wave runup
around 2 to 4 feet.

FIRE WEATHER...Fire weather activity will remain low through the
weekend. RH values are expected to remain above 30 percent in
most areas. Lowest RH values will occur across the Yukon Flats
this afternoon and may briefly touch 30 percent. Strong southerly
Chinook expected to develop along the Alaska Range by Sunday
afternoon and continue through midday Monday. For the latest
information go to www.weather.gov/arh/fire.

HYDROLOGY...Flood Advisory continues for Mile 6 Tetlin Rd with high
water likely through the weekend. High water is expected on rivers in
the Tanana Valley through the weekend. However, rivers have all
crested and are falling across the Interior. Expect rises next
week as remains of Typhoon Shanshan moves across Interior. For the
latest information go to www.weather.gov/aprfc.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Advisory for AKZ227.

High Surf Advisory for AKZ213.

High Wind Warning for AKZ223-AKZ225-AKZ226.

Small Craft Advisory for PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-
PKZ230.
&&

AUG 18