Small Craft Advisory 82, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
402 AM AKDT WED JUL 20 2016

.DISCUSSION...

Models...The 20/00Z solutions initialized quite well against the
20/06Z surface analysis. Run to run continuity is good with
similar solutions through around 60 hours. Still looking good for
a break from the westerlies beginning late Thursday and continuing
through next week as a trough develops over the state Friday then
shift west as a ridge builds north over the central and eastern
interior beginning Monday. Another round of rain over the
interior starting tonight and continuing on and off through the
weekend. The biggest difference is models not indicating nearly
as much rain over a longer period, so should not contribute
significantly to current high water issues. Precipitation amounts
from 0.25 to 0.75 inch through the weekend. Will use a blend of
current solutions and the forecast database to maintain
continuity. For precipitation will lean toward the NAM for
coverage and the ECMWF for amounts.

Aloft...At 500 HPA...Low over the eastern Beaufort Sea yesterday
has moved south of Banks Island at 518 dam and will continue to
move east into Canada. A series of shortwaves continues to spin
around it with the last one exiting the state later today. Ridging
extending out of the north Pacific over the eastern Bering Sea and
Gulf of Anadyr will rotate east over the west coast and Bering
Strait later today, then flattens out with the ridging south of
the Alaska range. This will allow a 552 dam low over the central
Bering Sea to move northeast over St Matthew Island by Thursday
evening, and over the lower Yukon Delta by Friday morning at 554
dam, and over the northern Gulf of Alaska at 551 dam by Saturday
morning. A 550 dam low will develop over the central arctic coast
and drift south over the interior Saturday evening then remain
quasi stationary over the interior through Sunday before drifting
over the west coast. Ridging will start building north over the
eastern interior Monday and by Wednesday 570 dam heights will move
over the southeast interior. At 850 HPA...Zero isotherm still over
the northeast corner of the state and will move into Canada by
Thursday morning, otherwise not much change in temperatures over
the remainder of the state until early next week when the
temperatures start to warm back up over the eastern interior.

Surface...A weather front lies west to east over the Brooks range
and will remain quasi stationary as waves move east along the
front through the weekend. A broad area of low pressure will
develop over the state with several weak low centers drifting
around. A 1002 mb low will develop over Prince William Sound
Friday afternoon and move south over the Gulf, then drifts
northeast over the southeastern interior by Sunday morning. A
1002 mb low will develop over the southwest mainland and drift
southwest to Dutch Harbor by Tuesday morning.

Arctic Coast and Brooks Range...cloudy conditions continue with a
few break possible. Temperatures a bit warmer across the area as
the cold air over the eastern arctic moves east into Canada. Winds
will switch from northwest to northeast as the low continues to
move east and high pressure builds over the arctic. Winds speeds
generally 5 to 15 mph with slightly stronger winds over the
eastern arctic today at 15 to 25 mph diminishing to 5 to 15 mph
late Thursday. Snow continues above 3500 feet in the eastern
Brooks range east of the Dalton highway this morning, but the
heaviest snow has ended and the warning will be cancelled. Snow
will taper off through the morning ending around noon.

West Coast and Western Interior...Showers continue this morning
over a large part of the forecast areas and they will spread to
the remainder of the area through the day. Rainfall amounts of
0.25 to 0.75 inch will be possible through Friday evening with the
heaviest amounts in the Nulato hills. Winds generally southwest to
northwest at 5 to 20 mph with the strongest winds along the coast
and lightest winds inland. Slightly cooler through Saturday then a
slight warm up.

Central and Eastern Interior...A couple more waves of showers/rain
headed across the interior will move into the area this evening
spreading over the central and eastern interior tonight. Rainfall
amounts of 0.25 to 0.75 inch will fall through Friday. Rivers in
the interior are already peaking from the last heavy rain and
starting the slow return to normal levels. The rainfall will occur
over a much longer period of time, and is not expected to be a
significant impact. Winds generally southwest to northwest at 5
to 15 mph through Thursday. Temperatures will remain cool with
highs in the 60s and lows in the 50s.

&&

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

&&

.FIRE WEATHER...Cloudy conditions will prevail with showers/rain
over the western zones today and spreading east tonight over the
central and eastern zones. There is a high probability of at
least one period of wetting rains over much of the forecast area
through Friday. Temperatures will remain cool across the forecast
area with Relative Humidity values mainly above 40 percent and
good to excellent overnight Relative Humidity recovery through the
week. Low probability of thunderstorm activity through Friday.

&&

.HYDROLOGY...Flood Advisory continues for the Chena river, see
latest statement for up to date information. Most rivers have
started to fall and the remainder will start falling today before
this next rainfall. Do not expect the upcoming rainfall to produce
any issues since it will be falling over a much longer period of
time and the amounts will be much lighter than the event earlier
this week.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Small Craft Advisory for PKZ245.

&&

SDB JUL 16