Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 240243
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
843 PM MDT Sat Mar 23 2024

.DISCUSSION...


EVENING UPDATE:
Some increase to the PoPs were made to increase snow wordage to
likely as the last round of this week`s storm begins to spread
across eastern Montana. Latest RAP mesoanalysis shows an area of
700 hPa frontogenesis advecting in from southeast Alberta toward
the Hi-Line, resulting in increasing base reflectivities in our
northern zones. At the time, the band of more moderate snow
showers is moving northeast out of southern Montana and will
impact locations near Glasgow late tonight and into the overnight
hours. Latest update to the wind/wind gust grids still suggest
thresholds below Blizzard Warning for any zone in the CWA, but
will continue to monitor gusts and visibilities south of the
Yellowstone River valley and re-evaluate throughout the night.
Buckle up, it`s gon` snow!

-Enriquez

PREVIOUS DISCUSSION:
Today through Sunday Night:
High (80 to near 100 percent) confidence remains for an impactful
winter storm with the combination of blowing snow and heavy snow
at times. Moisture is advecting in from the Pacific and Gulf of
Mexico with a broad low pressure system continuing to develop
over Colorado. Model soundings show the dendritic growth zone will
be broad to support higher snow ratios, particularly on Sunday.
Falling snow will be more prevalent south and west of Fort Peck
Lake, while blowing snow will be the main factor for the most
northeastern locations like Plentywood. In fact, up to a quarter
of the latest GFS ensemble solutions keep Plentywood dry, giving
the lowest confidence for impacts there while winds still gust up
to 40 mph. Elsewhere, a general 4-8 inches is likely to be common
with some higher amounts such as from upslope enhancement favored
along the Big Sheeps or Little Rockies.

A break in snowfall for areas east of Fort Peck Lake is expected
through the early evening, but any snow on the ground will still
lead to scattered areas of blowing snow. The main event will move
in by 9PM for all of northeast MT. The Winter Storm Warning
accordingly starts at 3pm and the snow/wind/cold combination for
newborn/expecting livestock is highlighted.

Monday through Wednesday:
While the snow will taper off and winds become calmer, the fresh
snow cover and northwest flow results in a much colder than normal
forecast. There is moderate (60%) confidence that many locations
in northeast Montana drop to near or below zero Tuesday morning.
While skies become more clear at times and inversions are expected
to develop each morning, fog concerns due to daytime melting are
limited at this time.

Thursday onward:
Slightly warmer temperatures are favored along with some unsettled
conditions lead to moderate (30-50%) confidence for light
precipitation to return by Thursday night.

Zanker/Stoinskers


&&

.AVIATION...
Update Time: 2000Z

FLIGHT CONDITIONS: IFR/MVFR, with occasional LIFR in moderate to
heavy snow.

WEATHER PATTERN: An upper level trough over the region will
continue to provide snowfall and blowing snow through this
evening, with TAF sites expected to vary between MVFR and IFR
through 03Z. After 03Z, another wave of energy within the trough
will help winds increase and allow for IFR conditions to remain
through Sunday night due to falling and drifting snow.

WINDS: East at 15 to 25 knots, with gusts to 35 knots until 00Z
Monday, then East at 10 to 16 knots.


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM MDT Monday for Central and
Southeast Phillips...Central and Southern Valley...Daniels...
Dawson...Eastern Roosevelt...Garfield...McCone...Northern
Phillips...Northern Valley...Petroleum...Prairie...Richland...
Sheridan...Southwest Phillips...Western Roosevelt...Wibaux.

&&

$$

weather.gov/glasgow


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