877
FXUS65 KGGW 052021
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
221 PM MDT Fri Jul 5 2024

.DISCUSSION...

KEY MESSAGES:

1) Scattered showers and thunderstorms will continue across NE
Montana through 8 PM MDT with an isolated wind threat, along with
localized heavy rainfall.

2) Active weather will remain in place through this weekend with
thunderstorm chances each afternoon and evening.

3) Hot and dry conditions look to develop next week.


WEATHER PATTERN OVERVIEW:

Forecast soundings this afternoon and evening show an inverted-V
signature. While 0-6 km shear is only around 20 kts, between 500
and 1000 MU CAPE indicates enough instability for ordinary cell
convection and weak multicellular structures. While the presence
of strong winds along to mix to the surface is lacking, collapsing
cells may produce isolated severe wind gusts aided through
evaporative effects in the dry boundary layer. HREF shows support
for isolated gusts to 60 mph this evening through about 02Z before
shifting east into the Dakotas. Brief heavy rainfall may result
with precipitable water around an inch or a little under and
six hour probability of 0.25" QPF or greater ranges from 50 to 70
percent with the more organized convection.

Active weather looks to continue through the weekend with chances
for showers and thunderstorms each day, especially during
afternoon and evening hours. Thereafter, expect strong upper
ridging to take hold across the western CONUS leading to dry and
hot weather conditions extending their reach into Northeast
Montana.
FORECAST CONFIDENCE & DEVIATIONS:

Confidence is low on exact placement and timing of individual
thunderstorms but high that an overall active weather pattern will
remain in place through this weekend. Given excellent model
consensus and previously explained reasoning for severe weather
today, confidence is near or a little above average on isolated
severe wind gusts occurring through this evening. Confidence is
also above average for hot and dry weather to develop next week.
While NBM was followed for the forecast with little change, manual
edits to include severe wording in the weather grids were made to
better underscore messaging of near term impactful weather.


&&

.AVIATION...
VFR conditions are expected to prevail tonight, though MVFR/IFR
ceilings and visibilities are briefly possible near any organized
storms. Expect gusty and shifting winds near thunderstorms through
02Z. Winds will become light and variable overnight.



&&

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

$$

weather.gov/glasgow