Severe Thunderstorm Warning 40, NWS Great Falls, MT

Area Forecast Discussion
National Weather Service Great Falls MT
928 PM MDT Sat Jun 14 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Daily rounds of widely scattered showers and thunderstorms
   continue through Tuesday, with a few of the strongest storms
   capable of localized strong, gusty winds, hail, and brief
   downpours.

 - Drier conditions with continued seasonable temperatures move
   in for the second half of the workweek.

 - Confidence is increasing for a period of cooler and wetter
   weather next weekend.

&&

.DISCUSSION...
/Issued 200 PM MDT Sat Jun 14 2025/

 - Meteorological Overview:

Scattered showers and thunderstorms will redevelop this afternoon,
mainly over the elevated terrain of the Little Belt and Snowy
mountain ranges. The afternoon upper air sounding at Great Falls
revealed a mid-level capping inversion and strong directional
shear, so any thunderstorms today will be rather weak until they
move further east into the Glasgow and/or Billings forecast areas.

More of the same is expected for Sunday, but a nicely timed
shortwave will increase bulk shear above 40 kts while CAPE
increases above 1,500 J/kg. This will serve to increase coverage
and intensity of storms with some westward expansion to include
most central/North- central and southwestern locations east of
I15. Additional rounds of showers and storms can be expected for
Monday and Tuesday with the continuation of the southwesterly flow
aloft, but there isn't as much of a signal for stronger activity
at this time.

The shower and thunderstorm activity looks to slow down a bit for
the second half of the workweek with more of a westerly flow
aloft. There will still shortwaves that bring opportunities for
spotty precipitation and breezy to windy conditions, but there
will be less moisture availability. Most ensembles bring the
southwesterly flow back to the Northern Rockies by next weekend as
a large trough digs into the Pacific Northwest. The NBM catches
this nicely with increased coverage of showers and thunderstorms.

 - Forecast Confidence & Scenarios:

There is a 40% chance of thunderstorms this afternoon over Judith
Basin and Fergus counties, mostly likely between 3-6pm. An
isolated severe thunderstorm to include hail or damaging winds
cannot be ruled out for this area.

With warmer temperatures and a stronger upper level shortwave
arriving Sunday afternoon, scattered thunderstorms are expected
over a larger area of central Montana. Although more numerous,
there is less confidence on the severe potential for these
thunderstorms. The scenario for Sunday looks similar to what we
just experienced Friday afternoon, with some isolated severe
activity moving away into eastern Montana.

One more round of thunderstorms appears likely for Monday
afternoon, although shifted further into Southwest Montana.

Ensemble clusters all depicts broad ridging over the region,
providing a period of relatively dry conditions Tuesday through
Thursday. Confidence is increasing on a period of cooler and
wetter than average weather for next weekend. Ensemble clusters
are aligning around the solutions for a large scale cut off low
over the interior northwest. Scenarios in these solutions range
from scattered showers or periods of rain, up to a slow moving
cut off producing stratiform rain or mountain snow over northwest
and central Montana.

&&

.AVIATION...
15/00Z TAF Period

Severe thunderstorms move across the area, this evening, hitting
portions of central Montana with large hail and heavy downpours.

Some sites dip into the MVFR range due to lower visibility in
rain/mist or during thunderstorms and rain showers.

Outside of areas impacted by thunderstorms and rain showers, winds
are, generally, light and variable.

Afternoon and evening thunderstorm activity impacts the region,
again, tomorrow.

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

&&

.PREV DISCUSSION...
/Issued 200 PM MDT Sat Jun 14 2025/

 - Meteorological Overview:

Scattered showers and thunderstorms will redevelop this afternoon,
mainly over the elevated terrain of the Little Belt and Snowy
mountain ranges. The afternoon upper air sounding at Great Falls
revealed a mid-level capping inversion and strong directional
shear, so any thunderstorms today will be rather weak until they
move further east into the Glasgow and/or Billings forecast areas.

More of the same is expected for Sunday, but a nicely timed
shortwave will increase bulk shear above 40 kts while CAPE
increases above 1,500 J/kg. This will serve to increase coverage
and intensity of storms with some westward expansion to include
most central/North- central and southwestern locations east of
I15. Additional rounds of showers and storms can be expected for
Monday and Tuesday with the continuation of the southwesterly flow
aloft, but there isn't as much of a signal for stronger activity
at this time.

The shower and thunderstorm activity looks to slow down a bit for
the second half of the workweek with more of a westerly flow
aloft. There will still shortwaves that bring opportunities for
spotty precipitation and breezy to windy conditions, but there
will be less moisture availability. Most ensembles bring the
southwesterly flow back to the Northern Rockies by next weekend as
a large trough digs into the Pacific Northwest. The NBM catches
this nicely with increased coverage of showers and thunderstorms.

 - Forecast Confidence & Scenarios:

There is a 40% chance of thunderstorms this afternoon over Judith
Basin and Fergus counties, mostly likely between 3-6pm. An
isolated severe thunderstorm to include hail or damaging winds
cannot be ruled out for this area.

With warmer temperatures and a stronger upper level shortwave
arriving Sunday afternoon, scattered thunderstorms are expected
over a larger area of central Montana. Although more numerous,
there is less confidence on the severe potential for these
thunderstorms. The scenario for Sunday looks similar to what we
just experienced Friday afternoon, with some isolated severe
activity moving away into eastern Montana.

One more round of thunderstorms appears likely for Monday
afternoon, although shifted further into Southwest Montana.

Ensemble clusters all depicts broad ridging over the region,
providing a period of relatively dry conditions Tuesday through
Thursday. Confidence is increasing on a period of cooler and
wetter than average weather for next weekend. Ensemble clusters
are aligning around the solutions for a large scale cut off low
over the interior northwest. Scenarios in these solutions range
from scattered showers or periods of rain, up to a slow moving
cut off producing stratiform rain or mountain snow over northwest
and central Montana.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  78  54  81  51 /  20  20  40  40
CTB  75  46  76  44 /  30  10  20  20
HLN  82  55  82  54 /  20  20  50  30
BZN  83  49  83  49 /  30  20  40  40
WYS  75  38  79  37 /   0   0  20  10
DLN  80  46  79  46 /  10  10  30  10
HVR  81  54  82  50 /  40  20  50  50
LWT  75  51  76  49 /  50  60  80  80

&&

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

http://www.weather.gov/greatfalls

Preliminary Local Storm Report
National Weather Service Great Falls MT
934 PM MDT Sat Jun 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0732 PM     Hail             3 NE Danvers            47.26N 109.67W
06/14/2025  E1.75 Inch       Fergus             MT   Law Enforcement

            Patrol car traveling along Highway 81
            received substantial hail damage. Location
            and time estimated based on radar.

&&

JTG

Special Weather Statement
National Weather Service Great Falls MT
949 PM MDT Sat Jun 14 2025

MTZ306-311-150415-
Northern Blaine County MT-Bears Paw Mountains and Southern Blaine MT-
949 PM MDT Sat Jun 14 2025

...STRONG THUNDERSTORMS WILL IMPACT SOUTHEASTERN BLAINE COUNTY
THROUGH 1015 PM MDT...

At 949 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 16 miles northwest of Zortman to near Hays.
Movement was northeast at 20 mph.

HAZARD...Wind gusts up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Hays and Lodge Pole.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4798 10849 4799 10860 4792 10864 4793 10879
      4812 10882 4835 10842 4834 10840 4822 10843
      4798 10843
TIME...MOT...LOC 0349Z 234DEG 21KT 4809 10876 4804 10864 4795 10872

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

RCG

Special Weather Statement
National Weather Service Great Falls MT
1028 PM MDT Sat Jun 14 2025

MTZ317-321-150500-
Little Belt and Highwood Mountains MT-Meagher County Valleys MT-
1028 PM MDT Sat Jun 14 2025

...A STRONG THUNDERSTORM WILL IMPACT EASTERN MEAGHER COUNTY THROUGH
1100 PM MDT...

At 1027 PM MDT, Doppler radar was tracking a strong thunderstorm 23
miles west of Harlowton, moving northeast at 25 mph.

HAZARD...Nickel size hail.

SOURCE...Radar indicated.

IMPACT...Minor hail damage to vegetation is possible.

Locations impacted include...
Martinsdale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4640 11032 4656 11045 4664 11028 4641 11028
TIME...MOT...LOC 0427Z 243DEG 21KT 4651 11031

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...<30 MPH

RCG

Preliminary Local Storm Report
National Weather Service Great Falls MT
1051 PM MDT Sat Jun 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0655 PM     Hail             3 E Moccasin            47.06N 109.84W
06/14/2025  E1.75 Inch       Judith Basin       MT   Public

            Report from social media showed golf ball
            sized hail as well as significant damage to
            outdoor play equipment and shattered
            skylights and windows. Time estimated from
            radar.

&&

JTG

Special Weather Statement
National Weather Service Great Falls MT
1109 PM MDT Sat Jun 14 2025

MTZ313-314-150600-
Judith Basin County and Judith Gap MT-Fergus County below 4500ft MT-
1109 PM MDT Sat Jun 14 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN JUDITH BASIN AND
WEST CENTRAL FERGUS COUNTIES THROUGH MIDNIGHT MDT...

At 1109 PM MDT, Doppler radar was tracking a strong thunderstorm 9
miles south of Denton, or 11 miles east of Stanford, moving northeast
at 25 mph.

HAZARD...Wind gusts up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Denton and Danvers.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 100 AM MDT for
central Montana.

&&

LAT...LON 4707 10999 4723 11011 4748 10968 4718 10941
TIME...MOT...LOC 0509Z 240DEG 23KT 4718 10997

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

Glinskas

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>