457
FXUS65 KGGW 192026
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
226 PM MDT Wed Jun 19 2024

.DISCUSSION...

KEY MESSAGES:
- A slow warm up is expected through Sunday when some 90s for
  highs likely appear.

- Shower and thunderstorm chances increase each day through
  Friday, when stronger storms and a more widespread wetting rain
  is expected.

WEATHER PATTERN OVERVIEW:
After a mostly dry day today, zonal flow along the northern CONUS
will continue to allow weak shortwaves to move through the area
through Saturday morning. This will produce hit-and-miss showers
and thunderstorms during this time. Most common area forecast
totals range from a quarter to half inch for areas hit during this
group of periods, but primarily Friday afternoon and evening.
Mainly general thunder is expected with any storms as they will be
embedded in rain showers, but a few stronger wind gusts over 40
mph can be mixed down to the surface with this activity.
Afterward, ridging will favor seasonably warm and drier
conditions by early next week.

FORECAST CONFIDENCE and DEVIATIONS:
Currently, there are no major signatures for severe weather
Thursday afternoon to Saturday morning in the synoptic scale for
the ensembles. However, this is just beyond the range of CAMs, so
that could change. There is high confidence (50-80%) in general
thunder with very minimal chances (10%) for any severe weather
over this period. A deviation from the NBM was made through
Thursday to expand coverage of isolated thunderstorm chances, and
increase winds/gusts to near the 90th percentile based on recent
model bias and climatology.

-Zanker/GAH

&&

.AVIATION...

LAST UPDATE: 2030Z

FLIGHT CAT RANGE: VFR.

DISCUSSION: Expect SCT to FEW mid to high clouds through the end
of the cycle. There is a low (20%) chance for an isolated
thunderstorm caused by daytime instability to briefly impact the
TAF sites both this evening and Thursday afternoon.

SFC WIND: Backing E to SE and becoming light late this evening
through Thursday morning. Then, increasing to 10-15 kts out of the
SE Thursday afternoon. Expect gusty and erratic winds near any
thunderstorms.

EQUIPMENT: We will continue to add "AMD NOT SKED" to the KSDY TAF
till its METAR is available again online.

&&

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

$$

weather.gov/glasgow