716
FXUS65 KGGW 260802
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
202 AM MDT Wed Jun 26 2024

.DISCUSSION...

KEY MESSAGES:

1) Dry weather continues today with near normal temperatures.

2) A strong cold front will push through the region on Thursday
with growing support for severe weather across NE Montana from Thursday
morning through Thursday evening.

3) Cool weather expected Friday and Saturday with chances for
showers and thunderstorms on Friday.

WEATHER PATTERN OVERVIEW:

Upper ridging will prevail over the area today with dry weather.
Surface low develops over central Montana tonight and ridge axis
moves east turning the flow aloft to the SW which will allow for
a chance of showers and thunderstorms. An upper low moves in from
the west on Thursday. The surface low moves east across eastern
Montana during the day on Thursday along with a surface cold
front. SE winds ahead of the cold front will bring dew points into
the 60s east of Glasgow and Jordan on Thursday. The mean surface
based CAPE over eastern portions of the CWA looks to reach 2000
J/KG or better by Thursday afternoon and evening while forecast
soundings show 40-50 kts of 0-6 km shear present. This will all
set the stage for the return of active severe weather across NE
Montana, especially during afternoon and evening hours. large hail
and damaging winds will be the main threats. Precipitable water
reaches 1.5 inches along the ND border Thursday afternoon and
evening which could lead to locally heavy rain.

Upper low/trough will move across eastern Montana on Friday with
more showers and thunderstorms possible especially in the north.
It will be a cool day with highs in the 60s NW and lower 70s SE.

An upper ridge moves into the area on Saturday with dry weather.
Warmer temperatures are expected on Sunday ahead of a cold front
Sunday night and Monday with an upper trough that will bring
chances for showers and thunderstorms.

FORECAST CONFIDENCE & DEVIATIONS:

The forecast followed NBM most of the time. Expanded the area of
severe thunderstorms during the day on Thursday and Thursday
evening beyond what the NBM forecasted to better match the SPC
forecast of slight risk of severe weather.

Confidence of high that there will be thunderstorms on Thursday
especially in the afternoon and evening. Confidence is low on
rainfall amounts as a few miles will separate whether a location
gets 0.1 inch or 1 inch or more rain. WPC has a slight risk of
excessive rain in Sheridan County on Thursday which looks
reasonable given the high precipitable water.

&&

.AVIATION...

LAST UPDATED: 0800Z

FLIGHT CAT: Areas of MVFR this morning. Otherwise VFR.

DISCUSSION: There are MVFR level low clouds along the MT/SK
border at 08z that area drifting south and dissipating before they
reach any TAF site. A few of these clouds could reach either KGGW,
KOLF or KSDY this morning before daytime heating dissipates these
clouds. Otherwise, skies will be mostly clear today with some
daytime cumulus this afternoon.

Mid and high level clouds will move into the area tonight with a
chance of showers and thunderstorms after 06z.

WIND: North 5 to 10 knots early veering to the east this morning
and SE 5 to 15 knots this afternoon. East winds 5 to 15 knots are
expected tonight.

&&

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

$$

weather.gov/glasgow