149
FXUS65 KGGW 140822
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
222 AM MDT Fri Jun 14 2024

.DISCUSSION...

KEY MESSAGES:

- Warmest day of the year so far for most of the region today.

- Showers and thunderstorms possible Friday afternoon, highest
  severe risk will be south of the Missouri River.

- Another round of thunderstorms Saturday, with eastern zones
  seeing the highest severe risk.

- Pattern change starting Sunday with well below average
  temperatures and more widespread rain by Monday.

WEATHER PATTERN OVERVIEW:

Warmest day of the year likely today with some locations
potentially seeing their first 90 deg reading of the summer. Upper
ridge begins moving east today with southwesterly flow moving into
the area. A few upper level disturbances along with some unstable
air moving into the region with a surface Low moving up from
Wyoming will generate some afternoon thunderstorms, with CAM
models showing the highest risk of strong to severe storms being
south of the Missouri River. Southeast zones are highlighted in a
Marginal Risk by SPC, will see if that risk gets potential moved
northward with their next update.

On Saturday the first Pacific Northwest Trough will begin to
settle into the area driving a cold front ahead of it. This will
not only be the beginning of a pattern change to below average and
wetter conditions, but this front will set off another round of
afternoon and evening thunderstorms. SPC has the eastern half of
our CWA in a slight risk for severe weather so this will have to
be monitored closely.

Highs Sunday behind the aforementioned front will be much cooler
than Saturday`s readings. A little break in the action overall
before a stronger Pacific trough moves in Monday bringing
widespread rain and even cooler temperatures at 10-20 degrees
below mid June averages for both Monday and Tuesday. Weak ridging
begins building on Wednesday starting a warming trend with
temperatures heading back toward seasonal averages by the end of
the week.

FORECAST CONFIDENCE and DEVIATIONS:

There is a moderate to high (60-90%) probability for a wetting
rain (0.10") across much of the region with the weekend system
with the highest chances in the northeast corner of the state.
Moderate probability (30-60%) of 0.25".

For the Monday/Wednesday AM system, QPF amounts are higher, with
a probability around 70-80% for at least 0.25", 50-60% for 0.50",
and 20-40% for 1".

-Bernhart


&&

.AVIATION...

LAST UPDATE: 0830Z

FLIGHT CAT RANGE: VFR

DISCUSSION: A chance of thunderstorms moves in by the afternoon
with some of the storms mainly south of the Missouri River
reaching severe levels, with strong wind gusts being the primary
hazard. Another round of thunderstorms is expected Saturday
afternoon area wide as a cold front pushes west to east.

WIND: SE-15-20kts, with a switch to NW-10kts between 00Z-03Z at
KGGW.

-Bernhart


&&

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

$$

weather.gov/glasgow