187
FXUS65 KGGW 300852
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
252 AM MDT Sun Jun 30 2024

.DISCUSSION...

KEY MESSAGES:

1) This evening, there are severe thunderstorms possible north of
HWY 2 and severe thunderstorms likely south of HWY 2.

2) Unsettled weather with frequent opportunities for
thunderstorms will continue the rest of the week.

WEATHER PATTERN OVERVIEW:
A strong shortwave trough will replace the currently benign
conditions. A strong cap is expected to erode along the high
terrain of central Montana late this afternoon, as moisture
advection will push dewpoints into the upper 50s to low 60s. Bulk
shear will mainly be above 40 knots, the low level jet will
eventually exceed 30 knots and MU CAPE values are expected to
exceed 800 J/kg. These ingredients will aid in thunderstorm
development beginning around 5 PM and there is moderate (50
percent) confidence for some of these storms to turn severe
trekking eastward. This activity is expected to continue through
around midnight before the storms weaken and/or move into North
Dakota. A cluster or line of storms producing severe wind is more
favored in this scenario, though a few cells containing severe
hail are a threat as well.

Beyond this time period, shower and thunderstorm chances continue
throughout the week, which will help limit high temps from
reaching 90 degrees for most of the area. The strength of
thunderstorms and amount of beneficial rain in this period are in
question based on northwesterly flow continuing through the end
of the week.

FORECAST CONFIDENCE & DEVIATIONS:
There remains high (80 percent) confidence of thunderstorms
occurring this evening, with low to medium (30 to 50 percent)
confidence on severe weather at any one location.

-Zanker/Stoinskers


&&

.AVIATION...

UPDATED: 0830Z

FLIGHT CAT: VFR through 00Z Monday, then scattered IFR.

DISCUSSION: Mostly sunny skies today will transition into a wave
of mid-level clouds with developing thunderstorms impacting TAF
sites after 00Z. Some of these may produce severe winds and
severe hail this evening, as well as reduce visibility and
ceilings down to brief IFR conditions.

WINDS: SE at 12 to 20 knots with gusts to 30 knots until 06Z
Monday, with intense gusty winds from thunderstorms after 00Z
Monday.

&&

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

$$

weather.gov/glasgow