610
FXUS65 KTFX 072036
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
236 PM MDT Mon Apr 7 2025

.KEY MESSAGES...

 - Pacific cold front moves across the region this evening,
   accompanied by locally windy conditions, scattered showers and
   a perhaps an isolated thunderstorm.

 - Periods of windy conditions persist through Wednesday with with locally
   stronger winds possible near areas adjacent to the Rocky
   Mountain Front.

 - Drier and milder conditions redevelop Thursday and Friday
   before the next Pacific upper trough begins to move into the
   area for the weekend.

&&

.DISCUSSION...

 - Meteorological Overview:

The upper ridge axis shifts east of MT tonight as an upper level
trough in the eastern Pacific broadens to the north a of fairly
potent (for April) Pacific upper level jet moving east between 40-
45N. The lead shortwave moving out of the trough Lifts out into
southern AB tonight while a Pacific cold front at the surface sweeps
east across north-central and southwest MT late this afternoon and
evening. A period of steadier precipitation with and following
the frontal passage will mainly be focused along areas of the
continental divide north of the Lincoln to the Canadian border,
while showers accompany front as it moves through areas to the
east and southeast. Drying affects in westerly flow over the
Rockies will limit the coverage of showers to isolated at best
over the Golden Triangle portion of north-central MT. Showers
will be more numerous across southwest MT this evening, where
enough weak instability may be present for an isolated
thunderstorm.

Wind is likely to be the more noticeable affect of the front at
most locations with a shift to gusty west winds occurring with
its passage and gusty winds persisting through most of tonight
and tomorrow across the N-central MT plains. A period of stronger
winds is likely to develop across western portions of north-
central MT late tonight through Thursday morning as a second
embedded shortwave disturbance tracks from NW MT into southern AB
with an associated 700mb wind maximum.

Snow levels lower to 5000-6000ft along the continental divide
late tonight and lower to less than 5000ft Tuesday morning, but
the intermittent nature of snow showers and air/road temperatures
only marginally near freezing will limit the potential for snow
accumulation on road surfaces. Weaker disturbances moving through
fast/moist westerly flow will bring additional rounds of
rain/snow showers through Wednesday, primarily focused along the
continental divide and parts of southwest MT.

 - Forecast Confidence & Scenarios:

Afternoon/Evening Showers and Isolated Thunder:
Aside from the small (<10%) risk for lightning through early this
evening, the convective nature of showers in SW and central MT
this evening and initially dry low levels could bring some
stronger wind gusts down in their vicinity.

Strong Wind Potential Tuesday:
As the shortwave and surface low pressure emerge in southern AB
Tuesday morning, a period of more favorable condtions for
mountian wave wind enhancement could allow wind gusts in excess of
55 mph to expand from the Northern Rocky Mtn Front to as far east
Cut Bank and eastern Glacier county.

Longer Range Outlook:
Warmer and drier conditions are on track to re-develop by Thursday
and Friday as a transient upper level ridge briefly amplifies
across the Northern Rockies. Looking ahead to the weekend and
beyond, there is reasonable agreement among longer range model
ensembles for upper upper level troughing in the vicinity and a
transition back to cooler and active weather. There still is a
great deal of uncertainty with the timing and other important
details of the troughing, but it is worth noting that a small
subset of longer range ensemble members (10-20%) continue to
support a spring-storm scenario with more significant precipitation.
Hoenisch

&&

.AVIATION...
07/18Z TAF Period

VFR conditions will prevail at all terminals during this TAF period.
At the end of this TAF period there will be rain showers at the KEKS
and KBZN terminals and winds will increase at all terminals except
for the KHLN and KEKS terminals. At the KBZN and KEKS terminals
between 08/00Z and 08/12Z there is a 20 - 40% chance for rain. At
the KHLN, KGTF, KLWT, and KHVR terminals between 07/22Z and
08/04Z and between 08/06Z and the end of the TAF period there is a
20 - 40% chance for rain and/or a rain/snow mix. Between now and
08/06Z there is a low (< 10%) chance for an isolated thunderstorm
at the KGTF, KHLN, KEKS, and KBZN terminals. Between 08/06Z and
the end of this TAF period there will isolated instances of low-
level wind shear and mountain wave turbulence across North-central
Montana. -IG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  40  56  36  57 /  20  10   0  10
CTB  36  51  34  53 /  10  10   0  10
HLN  37  56  36  57 /  40  20  10  10
BZN  35  54  31  55 /  40  40  10  20
WYS  30  48  23  50 /  70  70  40  10
DLN  36  54  32  55 /  30  20  10   0
HVR  39  59  34  60 /  10  10  10  10
LWT  38  54  34  52 /  30  20   0  10

&&

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

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