094
FXUS65 KGGW 230822
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
222 AM MDT Sun Jun 23 2024

.DISCUSSION...

KEY MESSAGES:

- Severe storms will be possible late this afternoon through the
  evening.

- High temperatures reaching into the mid 90s today near and south
  of the Hi-Line. This could have strong heat impacts for
  communities without air conditioning.

- Quiet weather early next week will be followed by more active
  weather for the latter part of next week.

WEATHER PATTERN OVERVIEW:
A ridge across the region will bring very high temperatures in the
mid 90s today. As the day continues the ridge will begin to break
down and move east. A surface trough hot on the heels of the ridge
axis will allow the atmosphere to rapidly destabilize in the late
afternoon.

SPC`s HREF`s 00Z run has multiple ensemble members pointing
towards the development of a cluster or single supercell north of
US-2 forming from about Valley county or southern Saskatchewan
and then heading east to southeast through Daniels, Sheridan, and
possibly Roosevelt counties. When looking at hourly NAM BUF
soundings across the region, multiple items line up that point
towards mainly large hail and gusty wind from this cluster as it
passes through the area into the evening hours. These include,
dewpoints above 55*F, CAPE up to 2500J/kg, Bulk Shear as high as
55kts, and updraft helicity greater than 200 at times. In
addition south of the Missouri river a few members are developing
a cluster that seems to have a greater chance for gusty to
damaging winds but less hail in general. The northern Cluster has
a higher probability(50%-70%) of forming than the southern cluster
(20-40%). Peak severe hours look to be around 23-04Z or 5-11PM
before activity either begins to die off or move into North
Dakota. Widespread rains outside of these clusters are NOT
expected. GAH

FORECAST CONFIDENCE & DEVIATIONS:
Confidence in thunderstorms across the region is high(60-80%),
but any particular location getting hit is more like (<15%).


&&

.AVIATION...

LAST UPDATED: 0830Z

FLIGHT CAT: VFR - MVFR

DISCUSSION: A clear morning will give way to thunderstorms in the
late afternoon and through the evening. A few cells could become
severe with damaging wind and large hail. Chief threat hours run
from 22Z-05Z.

WIND: E to SE and light through the morning. Veering to SE to S
and increasing to 10 to 15 kts gust 20 kts this afternoon into
the early evening. Gusty erratic wind possible near any
thunderstorms. Shifting NW behind a front around midnight.

GAH


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
None.


&&

$$

weather.gov/glasgow