165
FXUS65 KGGW 162124
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
324 PM MDT Thu May 16 2024

.DISCUSSION...

KEY MESSAGES:

- There will be repeated chances for showers and thunderstorms
  over the next several days.

- Gusty west winds up to 40 mph are expected Friday.

- Cooler temperatures are expected over the weekend.

WEATHER PATTERN OVERVIEW:

A strong jet stream from the Pacific Ocean up and over the Rocky
Mountains and their associated scattered showers today through
tonight, will become enhanced by a low pressure system dropping
out of the Canadian Rockies on Friday. This will provide a bit
more organization to the otherwise widely scattered rain showers
we have been seeing across the region lately. In addition, we are
expecting surface winds to increase up to 30 mph with some gusts
to 40 mph Friday morning through Saturday evening. A Lake Wind
Advisory has been issued to cover these concerns.

For Friday precipitation, model data is beginning to gather around
a similar solution. Convective activity should begin around mid-
day. The general trajectory of storms will be from Billings
northeastward toward Glendive. Stronger CAPE and slightly more
potential for severe thunderstorms will lie just off the southeast
corner of our Wibaux County. The possibility still exists for
some severe downdraft outflow winds from any of these storms
Friday afternoon and evening.

CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST:

High confidence exists on the general temperature trend through
Saturday and the gusty west winds Friday and Saturday. The
southwestern portion of the forecast area has a 60-90+ percent
probability of a 30 mph wind gust on Friday at this time while the
remainder of the area has weaker winds.

There is lower confidence on the timing of showers and
thunderstorms, as well as the total amount of rain for any
particular location.

In the near term (Day 1 through Day 2 night), I blended more with
the high resolution model data to try and pick out storm
initiation and movement. For Day 3 onward, I did not deviate from
the base forecast.



&&

.AVIATION...

PATTERN: Healthy flow off the Pacific Ocean continues to direct
periods of scattered rain showers and isolated thunderstorms. Any
NE MT TAF site may be briefly impacted. A more organized storm
system will direct storms toward KGDV and KSDY from the southwest.

FLIGHT CONDITIONS: VFR. Brief MVFR/IFR if a storm happens to pass
directly over a TAF site.

WINDS: From the WSW around 10 to 15 kts this afternoon, becoming
light and variable overnight. Early Friday winds from the SW at 10
kts, will turn more from the west and increase to 20 to 30 kts
through the rest of Friday and all of Saturday.

----BMickelson


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from 8 AM Friday to 9 PM MDT Saturday for
Central and Southeast Phillips-Central and Southern Valley-
Garfield-McCone-Petroleum.

&&

$$

weather.gov/glasgow