Special Weather Statement, NWS Glasgow, MT

Area Forecast Discussion
National Weather Service Glasgow MT
322 PM MDT Wed Jul 7 2021

.DISCUSSION...
Short term (tonight through Thursday night)...
Main focus here is the potential for severe weather. Storms have
begun to fire up in the lee of the mountains of Central Montana,
with one storm of note near Lewistown (as of 245pm MDT). Storms
should become more numerous as the evening progresses, especially
for areas south of US-2 and more so for areas south of the
Missouri River. A severe storm is possible just about anywhere,
with damaging winds being the primary threat. Severe thunderstorm
watch has just been issued for Garfield and Petroleum Counties,
and it's possible it could be extended further east later tonight.

By sunrise tomorrow, the area should be precip-free, but by late
morning additional storms will fire up near the Canadian border
and areas north of the Missouri River. These storms should begin
to drop south and east by the afternoon. Convective parameters for
Thursday suggest all modes are on the table in the afternoon and
evening. By the evening, storms should generally be out of the
area, with some lingering showers and non-severe storms lingering.

Any storms will also have the potential to produce locally heavy
rainfall, which is definitely welcome given the ongoing drought;
however, lightning strikes outside of any storm's rain area could
trigger wildfires.

In the far southwest part of the CWA, they should get rain from
this evening's storms then dry out tomorrow. In areas that don't
get much rain, the fire danger will be up, particularly in
southern parts of Garfield and Petroleum Counties.

Medium/long term (Friday and Saturday)...
Upper level ridging will begin to build in over the West Coast,
with an upper level high centered over the Southwest US. Northeast
Montana will be caught between the building ridge and a trough
over the Upper Mississippi Valley with disturbances traveling
through the flow that will trigger showers/storms on Friday before
the ridge begins to build over the area.

Sunday seems to be the hottest day of the forecast period, and
some spots could once again see elevated fire weather conditions
then. A few showers and thunderstorms are possible Monday and
beyond as disturbances travel through the flow, with the greatest
chances in the eastern part of the area.

97

&&

.AVIATION...
SKY CONDITIONS: VFR with periods of MVFR ceilings/visibilities
with thunderstorms this evening and tonight.

WINDS: SE-E 10-15 kts through early evening becoming light SE-E
overnight tonight into Thursday morning. Stronger and gustier winds,
with variable direction, are expected with thunderstorms this
evening and tonight.

SYNOPSIS: Showers and thunderstorms will impact TAF sites this
evening into the overnight hours tonight with gusty winds, large
hail, and LLWS possible with any storms. Showery weather, with
some thunderstorms, will continue to threaten TAF sites through
the morning hours on Thursday. Another round of thunderstorms with
gusty winds, hail, and LLWS potential will impact TAF sites
Thursday afternoon and evening.

97

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

weather.gov/glasgow

Special Weather Statement
National Weather Service Glasgow MT
358 PM MDT Wed Jul 7 2021

MTZ016-021-022-072245-
Petroleum MT-Garfield MT-Central and Southeast Phillips MT-
358 PM MDT Wed Jul 7 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN PHILLIPS...SOUTHWESTERN
GARFIELD AND PETROLEUM COUNTIES UNTIL 445 PM MDT...

At 357 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 20 miles east of Roy to 6 miles northwest of
Winnett to 10 miles southwest of Flatwillow. Movement was east at 40
mph.

Penny size hail and wind gusts of 50 to 55 mph will be possible with
these storms.

Locations impacted include...
Winnett, Flatwillow, Mosby, Crooked Creek Rec Area, Petrolia Lake,
Cat Creek and Tiegen.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
northeastern Montana.

LAT...LON 4727 10872 4727 10859 4730 10859 4731 10834
      4732 10831 4748 10831 4754 10790 4702 10781
      4685 10781 4685 10789 4682 10785 4680 10785
      4679 10784 4678 10785 4676 10783 4675 10863
      4684 10863 4684 10861 4710 10861 4710 10874
TIME...MOT...LOC 2157Z 271DEG 34KT 4736 10853 4704 10847 4670 10850

NWS Glasgow

Special Weather Statement
National Weather Service Glasgow MT
442 PM MDT Wed Jul 7 2021

MTZ021-022-072330-
Petroleum MT-Garfield MT-
442 PM MDT Wed Jul 7 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN GARFIELD AND
SOUTHEASTERN PETROLEUM COUNTIES UNTIL 530 PM MDT...

At 441 PM MDT, Doppler radar was tracking a strong thunderstorm 9
miles southeast of Winnett, moving east at 50 mph.

Penny size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Winnett, Flatwillow, Sand Springs, Mosby, Petrolia Lake and Cat
Creek.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
northeastern Montana.

LAT...LON 4675 10846 4713 10837 4715 10746 4685 10748
      4685 10789 4682 10785 4679 10784 4678 10785
      4676 10783
TIME...MOT...LOC 2241Z 287DEG 42KT 4692 10819

NWS Glasgow

Special Weather Statement
National Weather Service Glasgow MT
530 PM MDT Wed Jul 7 2021

MTZ022-080015-
Garfield MT-
530 PM MDT Wed Jul 7 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN GARFIELD COUNTY
UNTIL 615 PM MDT...

At 530 PM MDT, Doppler radar was tracking a strong thunderstorm near
Sand Springs, or 35 miles east of Winnett, moving east at 25 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Edwards and Sand Springs.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
northeastern Montana.

LAT...LON 4685 10784 4714 10771 4715 10726 4686 10726
      4686 10746 4685 10747
TIME...MOT...LOC 2330Z 271DEG 21KT 4706 10761

NWS Glasgow

Special Weather Statement
National Weather Service Glasgow MT
601 PM MDT Wed Jul 7 2021

MTZ060-080045-
Southwest Phillips MT-
601 PM MDT Wed Jul 7 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN PHILLIPS COUNTY
UNTIL 645 PM MDT...

At 601 PM MDT, Doppler radar was tracking a strong thunderstorm 14
miles southwest of Hays, or 18 miles west of Zortman, moving
southeast at 35 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Zortman and Landusky.

LAT...LON 4792 10889 4793 10866 4792 10865 4792 10863
      4798 10861 4794 10832 4760 10848 4760 10851
      4761 10851 4762 10852 4761 10853 4761 10858
      4775 10889
TIME...MOT...LOC 0001Z 300DEG 30KT 4787 10891

NWS Glasgow

<!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>

<!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>