Havre, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

713
FXUS65 KTFX 301713
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1113 AM MDT Sun Mar 30 2025

Aviation Section Updated.

.KEY MESSAGES...

 - The light snow over much of Southwest and Central Montana is
   expected to decrease throughout the day and into this evening,
   as temperatures remain cooler than normal.

 - After a mostly dry and warmer day on Monday, a slightly cooler
   and unsettled period develops for Monday night through
   Thursday.

 - Drier and warming conditions are then forecast for Friday
   through next weekend.

&&

.UPDATE...
/Issued 858 AM MDT Sun Mar 30 2025/
Updated forecast is out. Main adjustment was to add some fog/light
snow in Cascade County and to end the western portion of the
winter weather advisory.

The cloud cover has generally lowered over portions of North
Central MT, creating the fog over portions of North Central MT.
Because of the low ceilings, afternoon temperatures were lowered a
bit today over North Central MT. Additionally, a new band of light
snow was developing just before 9 AM over much of Cascade County.
This area of snow should decrease early this afternoon.

Further south, the snow is coming to an end over the western
portions of the CWA in Southwest MT. Thus the winter weather
advisory will end at 9 AM for our western zones and it is still on
track to end at Noon time for our eastern zones of Southwest MT.
Overall, any new snow accumulations this morning over the eastern
zones will be up to another inch. Brusda

&&

.DISCUSSION...
/Issued 858 AM MDT Sun Mar 30 2025/


 - Meteorological Overview:

Today through much of Monday... The shortwave trough responsible
for light snow across much of Southwest and Central Montana
overnight into this morning is forecast to weaken as it moves east
along the Montana/Wyoming border today, causing a gradual
decrease in the snowfall. Additional snowfall through this morning
should remain an inch or less at lower elevations and mostly 2 to
4 inches in the mountains, so will continue the Winter Weather
Advisories as is. A weak high pressure ridge is then expected to
move into the area behind the shortwave, which will bring mostly
dry conditions with temperatures closer to normal.

Monday Afternoon through Thursday... A low pressure trough off the
Canadian / Pacific Northwest coast is forecast to eject a low
pressure center into the Pacific Northwest Monday afternoon and
evening. The resulting southwesterly flow aloft over Montana will
bring increasing moisture and instability to the area, so have
added mention of a slight chance for thunderstorms during the
afternoon and early evening hours. This low is then forecast to
open up into a broad low pressure trough that settles over much of
the Western United States for Tuesday through Thursday, likely
bringing chances for precipitation each day, along with cooler
than normal temperatures. The period with the best chance for
widespread precipitation will be Monday night through Tuesday
evening as the main energy associated with the weakening low
pressure area passes overhead.

Friday through next Sunday... Ensemble cluster guidance is in
fairly good agreement in building some version of a high pressure
ridge into Montana through next weekend. Most of the clusters
(over 75 percent) continue to forecast the development of a fairly
stagnant rex blocking pattern with the low center over the Desert
Southwest with the high pressure ridge axis from the Pacific
Northwest into Montana. This is represented by a warming and
drying pattern for the forecast area.


 - Forecast Confidence & Scenarios:

Snowfall for the Monday night through Tuesday evening period...
The ECMWF Extreme Forecast Index has much of Southwest and Central
Montana in the 50th to 70th percentile for precipitation and
snowfall and between 0 and 1 for the Shift of Tails. Overall, this
does not indicate the potential for extreme snowfall amounts.
Forecast snow level values also remain in the 3500 to 4500 feet
range across the area, which would tend to lean toward mainly
mountain snowfall. The latest NBM probabilistic guidance gives a
50 to 80 percent probability for 4+ inches of snowfall over a
24-hour period at and above mountain pass level south of a Great
Falls to Lewistown line, a 40 to 70 percent chance of 6+ inches,
and a 30 to 60 percent chance of 8+ inches. Given that mountain
criteria for a Winter Storm Warning is 9 inches, current guidance
does not favor issuing a Winter Storm Watch at this time and would
lean more toward a Winter Weather Advisory. However, snowfall
amounts created separately from deterministic guidance suggests
the potential for slightly higher amounts, which may lean more
toward the issuance of a Watch. Will continue to monitor this
trend over the next couple of forecast cycles.
-Coulston

&&

.AVIATION...
30/18Z TAF Period

The initial concern this TAF period is for lingering light snow
and low clouds. Remaining snow is forecast to diminish this
afternoon, with ceilings slowly rising in most areas. Additional
low clouds will be a concern this evening and tonight, mostly
across the plains, but in some southwest MT valleys as well. Fog
will be a concern where skies at least briefly clear a bit tonight
on the plains. -AM

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  39  27  52  33 /  30  10  60  50
CTB  36  25  46  28 /  20  10  40  20
HLN  45  31  52  31 /  50  20  70  60
BZN  41  26  49  27 /  90  10  60  50
WYS  40  22  42  20 /  30  50  80  70
DLN  42  27  48  28 /  70  10  40  50
HVR  40  25  49  28 /  10   0  20  30
LWT  39  25  49  28 /  40  10  50  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon MDT today for Big Belt,
Bridger and Castle Mountains-Gallatin and Madison County
Mountains and Centennial Mountains-Little Belt and Highwood
Mountains-Snowy and Judith Mountains.

&&

$$
http://www.weather.gov/greatfalls