Small Craft Advisory 50, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
236 PM AKDT Sun Jun 10 2018

.SYNOPSIS...
Aloft...
A long wave trough now developing over Mainland Alaska and NW
Canada will deepen through Monday, then persist through mid-week,
and retrograde slowly in the second half of the week. This is
bringing a sharp pattern change to much colder than normal
temperatures through Tue, and remaining cool through the week.

A trough aloft from Barter Island to Umiat will move to
Demarcation Point to Anaktuvuk Pass by 4am Mon then move east and
weaken. Snow along and southeast of this trough will combine with
upslope flow to cause another 4-6 inches of snow over zone 206
through early Mon.

Surface...
A thermal low pressure trough from Eagle to Delta Junction
will move to Dawson to Tok by 4am Mon, and to Beaver Creek to
Chisana by 4 PM Mon. This is causing scattered to numerous
showers along the trough this afternoon that will continue
through Monday. Expect a few thunderstorms along this trough
through this evening, and a few southeast of Northway Mon PM.

A 988 mb low about 300 nm northeast of Demarcation Point will
weaken slowly and drift north through Tuesday. A cold front
stretching from this low to Inuvik to Fairbanks to Galena to the
Bering Strait will move to Eagle to Delta Junction to Talkeetna
by 4am Mon, to Eagle to Isabell Pass by 4pm Mon, to Eagle to
Mentasta Pass by 4am Tue, and then weaken in place. A band of
steady rain along the front will move southeast with the front.
Isolated thunderstorms will occur this afternoon in the area from
Fairbanks east following the front. Expect .10 to .25 inch of rain
with the front, with the heavier amounts east of Fairbanks. When
this front meets the higher moisture air with the thermal trough
late tonight and Monday it will cause heavy rain over the Alaska
Range east of Isabell Pass tonight and Mon with 1-2 inches
possible. Since this precipitation will be snow above 5000 ft
this will limit runoff. At this time expect sharp rises small
streams and rivers in the Eastern AK Range Mon-Tue, but flooding
not expected. This will need to be watched in case freezing levels
do not drop. Could see some snow down to 3500 feet following
front, but only expect light amounts as most precipitation will be
done before the cold air and lower freezing levels move in.

Southwest winds 15 mph gusting to 25 mph are occuring along and
just ahead of the front, turning North 15 g25 mph north of the
front. Gusts to 40 mph are occuring along the south slopes of the
Brooks Range, over the Western Interior, and West Coast along and
just following the front.

A ridge of high pressure stretching from Russia east across the
North Slope will weaken tonight. This is causing strong winds over
the zone 204 that will decrease through tonight as the high
weakens. This ridge is also causing

Rh has dropped to 25-30% north of the front along the south
slopes of the Brooks Range and northern Interior which will
combine to increase fire activity in the Northern Interior today.
RH will lower Mon, but winds will decrease Mon as well.

A weak frontal wave over the high arctic will move to 200 nm
northwest of Barrow as a 1014 mb low by 4pm Mon, to near Nuiqsut
as a 1013 mb low by 4am Tue, and to Umiat as a 1016 mb low by 4pm
Tue, and to south of Barter Island by Wed. This will bring a
batch of light snow to the North Slope Mon night into Wed.

&&

.DISCUSSION...
Models initialize well aloft, but are about 4 mb weak with the low
in the northern Beaufort Sea. Models show similar solutions
through 4am Tue, then start to diverge with the GFS and NAM
weakening the low aloft and moving it further southwest than the
ECMF does. At this time favor the GFS/NAM through Wed. GFS appears
to show areal coverage of precipitation better than the NAM, but
NAM may indicate upper limits of precipitation amounts better than
GFS. Winds are a bit stronger than models indicate over the
Northern Half of Alaska due to the Beaufort Sea low being a bit
deeper than initialized. As a result winds will be 3-5 kt
stronger than models indicate this afternoon and evening northern
half of Alaska.

For the second half of the week, models indicate long wave trough
persists through next weekend, but significant differences
between models on details. Will be using an ensemble approach and
keep temperatures below normal, but much uncertainty in regards to
details of weather.

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

&&

.FIRE WEATHER...
Rh has dropped to 25-30% north of the front along the south
slopes of the Brooks Range and northern Interior which will
combine to increase fire activity in the Northern Interior today.
RH will lower Mon, but winds will decrease Mon as well.

&&

.HYDROLOGY...
Expect .10 to .25 inch of rain with the
front, with the heavier amounts east of Fairbanks. When this front
meets the higher moisture air with the thermal trough late tonight
and Monday it will cause heavy rain over the Alaska Range east of
Isabell Pass tonight and Mon with 1-2 inches possible. Since this
precipitation will be snow above 5000 ft this will limit runoff.
At this time expect sharp rises small streams and rivers in the
Eastern AK Range Mon-Tue, but flooding not expected. This will
need to be watched in case freezing levels do not drop. Could see
some snow down to 3500 feet following front, but only expect light
amounts as most precipitation will be done before the cold air
and lower freezing levels move in.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Advisory for AKZ216-AKZ217-AKZ218.

Winter Storm Warning for AKZ206.

Frost Advisory for AKZ222.

Winter Weather Advisory for AKZ204.

Small Craft Advisory for PKZ210-PKZ215-PKZ220.

Brisk Wind Advisory for PKZ245.
&&

JB JUN 18

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>