Small Craft Advisory 71, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
215 PM AKDT Fri Jul 6 2018

.DISCUSSION...

Synopsis...Active across the area the next few days with
potential for a little bit of everything weather across the
forecast area from High Surf Advisories to Red Flag Warnings, to
sunshine and warm, to snow and cold, to thunderstorms and heavy
rain, to windy.

Models...Are in fairly good agreement with the latest solutions
from 06/12Z and initialized will at the surface against the 06/18Z
analysis. Very similar precipitation patterns in the GFS, NAM,
and ARW solutions, ECMWF spreading it out too much, so will use a
blend excluding the ECMWF this time around. All the solutions
indicating the Zero isotherm will dive south over the Arctic Coast
from Point Hope to Nuiqsut Saturday night, then gets pushed back
north Monday mid day. Convective indicies not very impressive
through the weekend, but they do support some thunderstorm
activity east of a line from Arctic Village to Fairbanks to Healy.
Probabilistic Surge Guidance indicates elevated sea heights as
the Extra Tropical remains of Prapiroon move to Nunivak Island by
Monday morning.

Aloft...At 500 hpa...A 515 dam low 700 nm north of point Barrow
will move east to 700 nm north of Demarcation Point by Saturday
morning, and to 300 nm north of Banks Island by Sunday morning,
then move into the Canadian Archipelago Sunday night. Ridging
persists over most of the state with a 573 dam high over the
Kotzebue Region today that will move over the Copper River Basin
by Saturday morning, and over the Southeast Panhandle by Sunday
morning with ridging extending northwest over Kotzebue Sound and
the southern Chukchi Sea. A broad area of lower heights over the
Bering Sea with a 553 dam center over the Western Bering Sea will
slide east to the Dateline with the low strengthening to 542 dam.
A shortwave in advance of the low will move to the southwest coast
tonight and push into the southwest mainland Saturday morning.
The low will continue to move east and will be over Nunivak Island
by Sunday morning at 531 dam. The low will stall over the lower
Yukon Delta through at least Tuesday as it pushes to the ridging
north with the ridge axis moving to lie from Dawson YT to Point
Lay. At 850 hpa...Most of the state well above 0C with a large
area above +10C over the Interior. Low over the high Arctic will
spin cold air south with the 0C isotherm moving south to Point
Barrow Saturday evening, and from Nuiqsut to Point Hope by Sunday
morning. +10C temperatures will persist south of the Brooks Range
and east of Tanana.

Surface...Stacked low over the Arctic with 976 mb low 700 nm
north of Point Barrow with a front extending south to the Eastern
Arctic Coast and inland to the Upper Yukon Flats. High pressure
persists over Interior Alaska and the West Coast with a 1023 mb
high near Kuskokwim Bay. Weak low pressure persists over the
Copper River Basin, South Central Alaska, and the Gulf of Alaska.
A 998 low, the remnants of Prapiroon, has moved to 100 nm
northeast of Shemya, and by Saturday morning it will be 200 nm
southwest of St Matthew Island near the Dateline at 991 mb, while
a 1006 mb low develops near Sand Point. High pressure will persist
over the interior mainly south and east of the Yukon River with
troughing over the Brooks Range then south over the Seward
Peninsula to the low near St Matthew Island.

Arctic Coast and Brooks Range...Cloudy with periods of dense fog
in some of the coastal areas mainly east of Wainwright. Cold air
will sink be pulled south bringing potential for some snow to the
coast from Nuiqsut to Point Hope. Inland areas will continue to be
much warmer than the coastal areas. Generally southwest to west
winds becoming west to north winds Saturday. Wind speeds 10 to 20
mph for most areas. Temperatures will fall sharply Saturday
evening over much of the area. Snowfall amounts will be light with
some areas of mixed rain and snow, and areas of rain further
inland.

West Coast and Western Interior...The extra tropical remnants of
Prapiroon will bring winds and rain to the area Saturday afternoon
into the middle of next week. Rainfall amounts will range up to
1.50 inches with the heaviest rainfall on St Lawrence Island, the
Lower Yukon Delta around Marshall, the Upper Kobuk near Ambler,
and the mountains of interior Seward Peninsula. Locally streams
may rise to bankfull, so use caution if attempting to cross them.
Temperatures cooling as cloudy and rainy conditions prevail.

Central and Eastern Interior...Will be pretty quiet, for the most
part through the weekend. Look for clearing tonight over most of
the Interior. Expect some isolated thunderstorms to the east of
Fairbanks. Strong gusty winds developing in the Alaska Range and
adjacent areas Saturday night and Sunday. Strongest winds near the
Richardson Highway north of Isabel Pass with gusts around 55 mph.
With the southwest flow strong winds expected from Dot Lake to
Tanacross as well with gusts around 35 mph. Temperatures will warm
quite a bit Saturday as the clouds have kept temperatures down
today. Highs will be about 5 to 10 degrees warmer Saturday then
cool back down on Sunday to the lower 70s.

&&

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

&&

.FIRE WEATHER...Quiet, but near Red Flag conditions in the Upper
Yukon Flats on Saturday afternoon for a few hours. Relative
Humidity values generally above 30 percent across the area with
just a pocket of drier conditions in the Flats. Southwest to west
winds pick up a through the day Saturday to 10 to 15 mph with
locally stronger winds to 25 mph over higher elevations. Relative
Humidity recovery will remain good with most areas recovering
above 70 percent. Thunderstorm activity restricted to areas east
of Fairbanks and will be pretty isolated. For the latest
information go to www.weather.gov/arh/fire.

&&

.HYDROLOGY...Water remains elevated above normal on most of the
rivers, but no significant issues currently or expected through
the weekend. Some moderate to heavy rain expected on the West
Coast and in the Western Interior Saturday, and Sunday, but not
enough to elevate rivers and streams significantly. For the latest
information go to www.weather.gov/aprfc.

&&

Extended forecast for days 4 to 7...Slightly cooler conditions
across the state with west flow developing aloft that could signal
a transition to the mid/late summer pattern with less convection
and more cloudy/rainy conditions.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory for AKZ226.

High Surf Advisory for AKZ207-AKZ213.

Small Craft Advisory for PKZ210-PKZ225-PKZ230.

Brisk Wind Advisory for PKZ240-PKZ245.

&&

SDB JUL 18