Wildfire in Montana, June 9 to 14, 2025

Area Forecast Discussion
National Weather Service Great Falls MT
1117 AM MDT Mon Jun 9 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Warm and dry today with temperatures in the upper 80s to low
   90s in the lower elevations.
 - Cooler and stormy weather expected the rest of the week, with
   some stronger storms possible.

&&

.UPDATE...
/Issued 846 AM MDT Mon Jun 9 2025/

Today it will hot with hazy skies around this morning before the
haze gradually moves out of North-central, Central, and
Southwestern Montana this afternoon through this evening. For the
update, temperatures across the area were increased to better
reflect the latest hi-res model guidance and current observations
and trends. Minimum relative humidity was decreased to better
reflect current observations and trends. Wind speeds and wind
gusts were increased across the area to better reflect current
observations and trends. Haze grids were refreshed to reflect the
latest guidance. The rest of the forecast is on track. -IG

&&

.DISCUSSION...
/Issued 846 AM MDT Mon Jun 9 2025/

 - Meteorological Overview:

Unseasonably warm temperatures are expected across North Central
and Southwestern Montana today as an upper level ridge makes its
presence felt across the region. Under this ridge, expect a fairly
calm day aside from the temperatures and some lingering smoke,
though even the smoke should thin out a bit more through the day
today. The warmth will come to an end on Tuesday as the upper
level ridge flattens and cooler air advects into the area from the
north. As the cooler air pushes in, moisture will build along the
Rocky Mountain Front, which will help initiate a few showers and
thunderstorms that will then spread eastward during the afternoon
and evening hours. For the rest of the week, our upper level ridge
will continue to gradually shift eastward, allowing southwesterly
flow to set up, which will bring multiple disturbances through
the area. Each of these disturbances will bring afternoon showers
and thunderstorms to the area, some of which may produce some
gusty erratic winds and marginally severe hail around an inch in
diameter.

 - Forecast Confidence & Scenarios:

Confidence in the overall pattern is very high this week, with
good agreement in a warm day today followed by a prolonged period
of temperatures closer to average with near daily chances for
showers and thunderstorms. Where uncertainty increases, however,
is in the strength and timing of showers on any given day. While
most storms should be normal, run of the mill showers and
thunderstorms, there is a small chance (5% chance of occurrence
within 25 miles) for some of these to produce some wind gusts to
around 60 mph and 1 inch diameter hail per the SPC on Tuesday and
Wednesday for at least a portion of the area (mainly along the
Rocky Mountain Front and over to White Sulphur Springs on Tuesday
and south of a Helena to Great Falls to Havre line on Wednesday).
With this pattern looking likely to repeat through the week,
expect some risk of a strong to severe storm to be present every
day this week from Tuesday onward. Ludwig

&&

.AVIATION...
09/18Z TAF Period

VFR conditions will prevail throughout the duration of the
0918/1018 TAF period; however, lingering smoke/haze from
wildfires burning in Canada will continue to reduce slantwise
visibility upon ascent/descent. Mountain obscuration due to cloud
cover is not expected until after 18z Tuesday when showers and
thunderstorms will begin to develop and lift northeast across
Southwest through North Central Montana. - Moldan

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  91  56  84  53 /   0   0  20  30
CTB  90  51  79  50 /   0   0  20  40
HLN  92  59  87  55 /   0   0  30  30
BZN  88  53  85  50 /   0   0  20  40
WYS  79  41  77  40 /   0   0  40  40
DLN  86  51  84  50 /   0   0  30  20
HVR  95  53  83  53 /   0  10  10  70
LWT  85  54  80  51 /   0   0  20  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

http://www.weather.gov/greatfalls