000
FXUS65 KGGW 020857
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
257 AM MDT Thu May 2 2024

.DISCUSSION...

KEY MESSAGES:

- *** Winter Weather Advisory remains in effect for the higher
  elevations of the Little Rocky Mountains in southwest Phillips
  County through 4 PM Friday.

- Cold front this morning brings rain and snow showers with
  isolated thunderstorms. The chances for rain and snow showers
  continue through Friday.

- Northwest winds 15 to 25 mph today will result in a Lake Wind
  Advisory for Fort Peck Lake.

- Nighttime temperatures will drop below freezing in many areas
  tonight through Friday night.

- Another round of rain showers are expected next week, starting
  late Sunday. Some places could receive an inch or more of rain
  Monday through Wednesday.

WEATHER PATTERN OVERVIEW:
A slow moving upper level low pressure system near the US/Canada
border will finally lift northeast away from the area late Friday.
This will allow for a break in the action before another upper
low moves in on Sunday.

Look for rain and snow showers and isolated thunderstorms to move
into NE Montana this morning. It will be a cool day, and cool
enough that snow levels will lower for mostly snow in the Little
Rockies of southwest Phillips County, and a mix of rain and snow
showers over the remainder of Phillips and along the Canadian
Border today. Temperatures will be cold enough tonight and Friday
morning for snow showers in most areas. Areas along the Canadian
Border could see up to an inch of snow through Friday while
higher elevations of the Little Rockies could see up to 5 inches
of snow.

Upper ridge moves through the area on Saturday with dry and warmer
weather. Sunday will be the warmest day as the ridge moves to the
east and the next system approaches from the west.

This next system moves in from the west Sunday night and becomes a
stacked low over the region on Monday. Models and EC/GFS/CMC ensemble
mean have decent agreement in the low meandering along the
Montana/Dakota border on Tuesday before weaken into an upper
trough on Wednesday. It will be a widespread rain event that could
last several days. Probability of at least one inch of rain
between Sunday night and Wednesday is 40-60% at this point and the
probability of at least 2 inches of rain is 10-30%.
CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST:

Confidence is high on the showers behind the cold front today but
whether it will be rain or snow showers at a given point and time
will depend on temperatures. High confidence on 2-5 inches of
snow in the Little Rockies today through Friday. Low confidence
on the possibility of thunderstorms today and snow accumulations
outside of the Little Rockies. Medium confidence the rain/snow
showers continuing through Friday.
High confidence on the dry weather on Saturday and rain that
starts Sunday night and lingers through at least Thursday. Lower
confidence on rainfall amounts.



&&

.AVIATION...

LAST UPDATED: 0840Z (2:40 AM, Thursday, May 2nd)

FLIGHT CAT: VFR early, becoming MVFR/IFR this morning at KGGW and
KOLF, and becoming a mix of VFR-MVFR this afternoon and evening
at KSDY and KGDV. A mix of MVFR-IFR late tonight.

DISCUSSION: A cold front will move through the area this morning.
A mix of rain and snow showers are expected today and tonight with
low clouds that will vary from MVFR-IFR at KGGW and KOLF and low
VFR to MVFR at KSDY and KGDV. Thunderstorms are possible again at
times today and this evening. Isolated to scattered snow showers
are expected tonight and Friday.
WIND: From the west and southwest at 5 to 10 kts early. Then from
the northwest at 15 to 20 kts during the afternoon and evening
hours, and northwest 5 to 15 kts late tonight.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from 10 AM this morning to 8 PM MDT this
evening for Central and Southeast Phillips-Central and Southern
Valley-Garfield-McCone-Petroleum.

Winter Weather Advisory until 4 PM MDT Friday for Southwest
Phillips.

&&

$$

weather.gov/glasgow