279
FXUS65 KGGW 090923
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
323 AM MDT Sun Jun 9 2024

.DISCUSSION...

KEY MESSAGES:

- Numerous rain showers and isolated thunderstorms will arrive
  from the southwest this evening and linger into Monday.

- A general warming trend to above-normal temperatures is expected
  through the remainder of the forecast period.

WEATHER PATTERN OVERVIEW:
The hi-res models are proving valuable with any showers and
convection from daytime instability over the last few days. They
suggest there will be a few sprinkles or light showers across NE
Montana by this afternoon. The flow pattern turns more from the
southwest this evening ahead of a low pressure trough coming over
the Rockies. This will provide an increase in low level moisture
and enough forcing to suggest more widespread showers, though
limited shear/instability for strong thunderstorms. The HREF keeps
most of the potential for 50-60 mph wind gusts over southeast
Montana this evening. There is around a 50 percent probability of
a quarter inch of rain and a 20 percent probability of a half inch
rain for most of NE Montana tonight through Monday.

An upper level ridge pattern will then build north on Tuesday,
but just reaching to near the Canadian border. This will mean a
seasonable warming trend and dry conditions, aside from occasional
opportunities for convection from passing shortwaves.

FORECAST CONFIDENCE and DEVIATIONS:
Some fine-tuning of precipitation chances and slight increases in
winds through Monday reflect deviations from recent biases and
lack of detail from the NBM. Confidence is high in the overall
pattern through midweek, while medium for the extent of both wetting
rains and stronger thunderstorms tonight.

-Zanker

&&

.AVIATION...

LAST UPDATE: 0830Z

FLIGHT CAT RANGE: VFR - MVFR

DISCUSSION: Scattered mid-level clouds over the area today will
generally bring no more than a few sprinkles from weak
instability. However, a more organized system will begin to
overspread the region after 00Z with numerous showers and
isolated thunderstorms. Lowering ceilings and higher rainfall
rates with any thunderstorms give medium (40%) confidence for a
period of MVFR before 12Z Monday.

WIND: From the northeast around 10 knots, becoming east at 15 to
20 knots after 18Z. Gusty and erratic winds may occur in the
vicinity of thunderstorms.

&&

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

$$

weather.gov/glasgow