Heavy Snow in Montana, December 30, 2018

Area Forecast Discussion
National Weather Service Great Falls MT
518 PM MST Sun Dec 30 2018

.UPDATE...
Updated forecast to change the advisory to a warning for the
southern and eastern portions of Cascade County. A few reports of
7 to 8 inches south of Belt and around Monarch. Another 2 to 4
inches possible overnight in this area. Light snow is back
building towards Great Falls, could get another 1/2 to 1 inch in
the city, so kept the advisory going there. Elsewhere, the
forecast is on track. The cold front is not well south of Bozeman.
Poor visibility and gusty north winds continue for a few hours
behind the front. Temperatures falling into the teens is freezing
roadways, creating icy road conditions. Brusda

&&

.SYNOPSIS...

Snow gradually ends overnight as colder air flows into the
region. Temperatures will drop to near zero for most areas by
early Monday. Very cold temperatures persist on Monday into Monday
night. Warmer and windy conditions return by the middle of the
week.

&&

.AVIATION...
Updated 0015Z.
Cold front is now south of Bozeman. Gusty north winds and poor
visibility continue for a few hours behind the front. Periods of
snow will continue over Central MT overnight. Low clouds with IFR
conditions likely to continue over central/southwest MT overnight.
Expect improving conditions on Monday afternoon across the region.
Brusda

&&

.PREV DISCUSSION...
/ISSUED 302 PM MST Sun Dec 30 2018/

Strong surface pressure rises indicate the continuing progression
of a much colder airmass into the region. Gusty north winds
accompany the pressure rises, and may cause localized areas of
drifting or blowing snow. Light snow is gradually tapering across
North-central Montana. Periods of snow will continue to advance
through central and southwest Montana this evening. Winter weather
advisories remain in place over most of our counties, with a
Winter storm warning continuing over the Rocky Mountain Front.
Some adjustments may be needed to these headlines later in the
evening. Roads will remain icy and snow covered as temperatures
continue to fall. Low temperatures early Monday morning will drop
to near zero, with wind chill values well into the teens to near
20 below zero.

Skies begin to clear on Monday as the upper level trough moves
away to the east. Temperatures on Monday remain well below
average, with highs only reaching the lower teens. The clear skies
and light winds could enable even colder temperatures Tuesday
night in the elevated southwest valleys, where lows could reach
near 20 below zero. Temperatures begin to moderate on Tuesday, but
breezy west winds over western portions of North-central Montana
will continue to maintain uncomfortably cold conditions for those
outside. PN

Wednesday through Sunday...Wednesday, a short wave ridge builds
into the area. Chilly morning temperatures start the day as the
leading edge of the ridge moves cold air from Canada into Montana.
As the day progresses, the ridge flattens and a strong westerly
cross barrier flow sets up, causing gusty winds to begin to
develop, again. The strongest winds occur along the northern Rocky
Mountain Front. Expect dry conditions on Wednesday, with high
temperatures rebounding to more seasonal values for this time of
year. Thursday, expect windy weather, with strong gusts along the
Rocky Mountain Front and gusty winds progressing into north and
central Montana. Moisture spilling into the ridge, ahead of a
major short wave trough approaching from the west, will provide a
chance for some precipitation to fall along the northern Rocky
Mountain front through Saturday afternoon. For the weekend,
ridging holds out against the approaching trough, and subsidence
and drying prevail. The surface pressure gradient loosens, and
winds decrease, becoming more breezy than strong, providing the
Treasure State with pleasant weather for the first weekend of the
New Year.
- Fogleman

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF   1  13   2  26 /  80  20   0   0
CTB   0  16   6  29 /  60  10   0   0
HLN   6  15  -3  24 /  70  20   0   0
BZN   2  12  -9  20 /  70  20   0   0
WEY -12   9 -25  11 /  70  10   0   0
DLN  -2  11  -8  19 /  70  10   0   0
HVR   1  12  -1  28 /  50  20   0  10
LWT  -2   7  -8  26 /  70  30   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 2 AM MST Monday Broadwater...
Central and Southern Lewis and Clark...Jefferson.

Winter Weather Advisory until 11 PM MST this evening Chouteau...
Eastern Glacier...Eastern Pondera...Eastern Teton...Fergus...
Liberty...Toole.

Winter Weather Advisory until 11 PM MST this evening
Beaverhead...Gallatin...Madison.

Winter Weather Advisory until 9 AM MST Monday Judith Basin...
Meagher.

Winter Storm Warning until 9 AM MST Monday Cascade.

Winter Storm Warning until 2 AM MST Monday Northern Rocky
Mountain Front...Southern Rocky Mountain Front.

Winter Weather Advisory until 9 AM MST Monday Cascade.

&&

http://www.weather.gov/greatfalls

<!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>

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
252 PM MST SUN DEC 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1230 PM     SNOW             CHOTEAU                 47.81N 112.19W
12/30/2018  E4.0 INCH        TETON              MT   TRAINED SPOTTER

            4 INCHES OF DRIFTING SNOW IN THE PAST 6
            HOURS.

&&

BRUSDA

Special Weather Statement
National Weather Service Great Falls MT
339 PM MST Sun Dec 30 2018

MTZ012-014-050>055-310030-
Cascade-Central and Southern Lewis and Clark-Judith Basin-Fergus-
Jefferson-Broadwater-Meagher-Gallatin-
Including the cities of Great Falls, Cascade, Belt,
Kings Hill Pass, Helena, Flesher Pass, Lincoln, MacDonald Pass,
Rogers Pass, Raynesford, Stanford, Hobson, Lewistown, Winifred,
Lewistown Divide, Grass Range, Montana City, Boulder,
Boulder Hill, Elk Park Pass, Homestake Pass, Whitehall, Toston,
Townsend, Winston, Martinsdale, White Sulphur Springs, Bozeman,
West Yellowstone, Battle Ridge Pass, Bozeman Pass,
and Targhee Pass
339 PM MST Sun Dec 30 2018

...Areas of moderate snowfall will continue into the early evening
hours...

Areas of moderate snowfall and poor visibility will continue into
the evening hours over portions of Central and Southwest MT. As of
330 PM, the heaviest snowfall was occurring over the eastern
portions of Cascade County, eastward to Lewistown, then southward
through the Helena Valley and into the Bozeman area.

Visibility is reduced to less than a half mile at times in areas
of falling and blowing snow. Wind gusts of 30 to 40 mph will
continue in this region into the early evening hours. New snow
accumulations of 1 to 2 inches are possible by 7 PM, but with the
blowing snow, some drifting of the snow will occur.

With colder air moving into the region, wet roadways will freeze
over, especially after sunset. Expect slowly improving conditions
after 6 PM this evening.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
434 PM MST SUN DEC 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 PM     HEAVY SNOW       4 N MONARCH             47.15N 110.84W
12/30/2018  E7.0 INCH        CASCADE            MT   TRAINED SPOTTER

            ESTIMATED 7 INCHES OF NEW SNOW TODAY.

&&

BRUSDA

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
521 PM MST SUN DEC 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     HEAVY SNOW       CHOTEAU                 47.81N 112.18W
12/30/2018  M8.0 INCH        TETON              MT   PUBLIC

            STORM TOTAL SNOW OF 8 INCHES REPORTED IN
            CHOTEAU.

&&

ERG