National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KGGW 230306 AAA
AFDGGW

Area Forecast Discussion...UPDATED
National Weather Service Glasgow MT
906 PM MDT Mon Apr 22 2024

.DISCUSSION...

EVENING UPDATE: It took a while, but winds speeds have diminished
generally below 20 mph and humidity has recovered above 30
percent to allow the Red Flag Warning from earlier today to be
cancelled shortly before 9:00 PM. Isolated rain showers are still
expected over the next few hours, especially near our borders with
Saskatchewan and North Dakota. Observation sites near Fort Peck
Lake still show winds a bit gustier, so we have chosen to not yet
cancel the Lake Wind Advisory on this shift. Made some adjustments
to the short-term forecast to reflect these observations and
expectations tonight. ---BMickelson

Morning Update:
Pretty much kept what going forecast had with this
update. But did refresh Winds and Sky with the latest guidance
numbers and added wording with thunderstorms of Gusty Winds. Rest
of forecast looked good. TFJ

Previous Discussion...
KEY MESSAGES:

1) Strong west to northwest winds in all areas with critical fire
weather south of US Highway 2 today.

2) Showers and isolated thunderstorms are expected north this
afternoon and evening.

3) Otherwise, a broad ridge pattern builds into the area this
week resulting in mostly dry and seasonable conditions.

WEATHER PATTERN OVERVIEW: Stacked upper/surface low will move
across southern Saskatchewan today bringing strong west to NW
winds over the forecast area. There will also be some rain showers
spinning around this low, some of which will move across the
northern zones of the forecast area this afternoon and evening.
The atmosphere is expected to be unstable enough this afternoon
and evening for isolated thunderstorms to mix in with those
showers. While NBM has forecast reaching wind gust around 50 mph
today in some areas, the probability of wind gusts exceeding 55
mph is less than 30 percent in most areas and as high as 50
percent in parts of Phillips and Valley Counties. At this point,
the probability of reaching High Wind Warning criteria is low
enough that we will hold off on issuing any High Wind Warning and
maintain a Lake Wind Advisory over Fort Peck Lake. The most likely
scenario for any spot getting a 60+ mph wind gust today would be
in a rain shower or thunderstorm. South of US highway 2, RH less
than 25 percent will create critical fire weather conditions today
and a Red Flag Warning remains in effect.

The low moves to the east tonight and high pressure moves in
diminishing the winds. Upper ridge moves in and by Wednesday,
temperatures will be warmer than normal. A shortwave trough brings
a cold front through the area on Thursday with slightly cooler
temperatures on Friday. An upper trough is expected over the
weekend but models and ensembles differ on the weather associated
with this system at this time.

CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST:

Confidence is high for strong winds in all areas today. Confidence
for wind speeds to reach High Wind Warning Criteria (gusts 58+
mph) is low and too low to issue a Warning. Confidence for
critical fire weather conditions today is high south of the
Missouri River and over the Little Rocky Mountains and diminishes
significantly north of US Highway 2 where much higher RH is
expected. With SPC having the northern zone of the forecast in a
general thunderstorm outlook for today, add the possibility of
thunderstorms that the base forecast did not have.

High confidence in the mid week ridge and cold front on Thursday.
Low confidence of precipitation chances over the weekend.



&&

.AVIATION...

LAST UPDATED: 0300Z

FLIGHT CAT RANGE: Borderline MVFR early tonight, then VFR

DISCUSSION: Tightly-wound upper level storm system over
Saskatchewan and Manitoba is quickly moving eastward and taking
the rain showers and strong winds with it. Expect overall weather
conditions to improve now through tonight. Although some locations
may drop down to freezing temperatures by Tuesday morning.

SFC WIND: Light and variable, if not calm.

-----BMickelson


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 6 AM MDT Tuesday for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

&&

$$

weather.gov/glasgow