842
FXUS65 KGGW 300240
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
840 PM MDT Wed May 29 2024

.DISCUSSION...

UPDATE...
Convection across northeast Montana continues this evening along
a narrow stretch near the MT/ND state line. However, radar trends
and spotter reports across the area continue to indicate
convection steadily weakening. Additionally, the latest high-res
model data continues to show the greatest probabilities of severe
wind and hail criteria remaining east of northeast Montana.
Therefore, the severe thunderstorm watch that was previously in
effect this evening across a portion of northeast montana, has
been cancelled. A few storms this evening may still generate
small hail, winds to 45 mph or brief heavy rainfall.


PREVIOUS DISCUSSION...

KEY MESSAGES:

1) Strong convection has begun over southeastern Montana and is
expected to develop and propagate northward. A Severe Thunderstorm
Watch has been issued for our south central and eastern zones
bordering North Dakota.

WEATHER PATTERN OVERVIEW:

Cold front this evening will push any lingering severe storms
into North Dakota and Saskatchewan. For our northeast Montana
zones, most of the threat seems to be a thunderstorm downdraft
wind moving from east to west across the border. Threats will be
very near our shared border, so a close weather watch is needed.

Thursday into Thursday night: Center of the entering trough will
move across the area and rain showers and isolated thunderstorms
will linger through these periods.

Friday onward: Expect a warming trend with a large ridge
developing over the western half of the CONUS. The crest of the
ridge will nudge northward into Montana Saturday and herald the
arrival of Montana Summer with afternoon 80s becoming more common.

CONFIDENCE & DEVIATIONS:

A few mesoscale difference exist in model groupings with this
evening`s storm passage. Some ensemble breakdowns occur in
synoptic features beginning to set in around Thursday night into
Friday as models resolve exactly how fast the trough exits and the
next ridge enters. Here onwards is where confidence breaks down
to moderate.


&&

.AVIATION...

VFR through late this afternoon when a cold front will cross the
region with scattered showers and thunderstorms. Some of the
stronger storms could result in brief periods of IFR or worse for
KSDY and KGDV if a storm happens to pass directly overhead.

Winds will increase from the northwest behind the cold front,
Gusty, erratic, severe wind gusts are expected near the stronger
storms this evening.


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 9 PM MDT Thursday for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

&&

$$

weather.gov/glasgow