Flood in Montana, April 1 to 2, 2020

Area Forecast Discussion
National Weather Service Glasgow MT
714 PM MDT Tue Mar 31 2020

.DISCUSSION...
...Winter Storm will impact parts of NE Montana tonight and
Wednesday morning...

Evening Update...

Fairly significant changes were made to the forecast this evening
with regards to expected snowfall tonight and tomorrow. A 700 mb
low will track generally along the Missouri River tonight into
tomorrow morning. This will be a focal point for the heavy
snowfall axis.

North of this low, dry air will be funneled into the area from the
Canadian Prairies. This will lead to significantly less snow along
and north of Highway 2 compared to areas farther south. It would
not be surprising if some areas even received no precipiation at
all as you got closer to the Canadian border. This thinking has
been reflected in the latest forecast with reduced snowfall
totals. There will be a sharp gradient somewhere near the
Missouri River where snow totals go from an inch to 6 inches in
just 50 miles or so.

The most likely area for the heaviest snowfall will be across
northern Petroleum and northern Garfield Counties. Up to 7 inches
of snow is a possibility here, therefore this area has been
upgraded to a Winter Storm Warning beginning at midnight. Snowfall
totals were also increased farther east across McCone County and
in the Big Sheeps. Up to 5 inches of snow can be expected in these
locations.

-Mottice

Previous Discussion...

Complex winter storm will feature the secondary cold front moving
through the CWA tonight and Wednesday morning. Cold air behind
this front has nodes down the Canadian Rocky Mountain Front with
temperature this hour only in the teens over southern Alberta. A
closed upper low will continue drifting southeast and moisture and
energy to override this cold air, bringing moderate to possibly
heavy snow at times late tonight/Wednesday, especially for the
western zones. The combination of the wind and the snowfall over
the western zones looks to occur over the eastern zones
Wednesday, thus the Winter Weather Advisories have been extended
to the ND border for most zones. Snow amounts in the advisory zone
are expected to be 2 to 5 inches. Combined with the wind, it won't
be an April Fools joke for most.

Wednesday Night into Thursday morning, temps will plummet with
the wind to bring Windchills below zero for most, making it rough
for calving operations. Another system will bring snow to
southeast Montana and shouldn't be a big concern for our SE zones.

Conditions will gradually modify as dry conditions and
temperatures return to the 30s Friday, 40s Saturday. Normal high
and low temperature for Glasgow this time of year is in the low
50s and upper 20s. TFJ

&&

.AVIATION...

FLIGHT CAT: VFR this evening, MVFR-IFR late tonight and Wednesday.

A second cold front will be exiting this evening with another
round of mainly snow developing later tonight that gradually ends
from west to east Wednesday afternoon. Several inches can be
expected.

Winds will be NW then North tonight at 15 to 30 kts that continues
Wednesday. TFJ

&&

.HYDROLOGY...
Upcoming colder temperatures will temper the flow on area creeks
and streams over the next few days. However, temperatures will
quickly rise again this weekend into next week and this will lead
to continued flooding on the Milk River.

To keep track of stream levels, see our AHPS page at
water.weather.gov

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from midnight tonight to 3 PM MDT Wednesday
for Garfield...Petroleum.

Winter Storm Warning until noon MDT Wednesday for Southwest
Phillips.

Winter Weather Advisory from midnight tonight to 6 PM MDT
Wednesday for Dawson...Eastern Roosevelt...McCone...Prairie...
Richland...Sheridan...Western Roosevelt.

Winter Weather Advisory from midnight tonight to noon MDT
Wednesday for Central and Southeast Phillips...Central and
Southern Valley.

&&

weather.gov/glasgow