Alert archive / Montana / Special Weather Statements in 2021

Special Weather Statement, NWS Great Falls, MT

July 7, 2021Glacier County, Montana

NWS Great Falls, MT issued this special weather statement at Jul 7, 2021, 9:33 PM MDT for Glacier County, Montana. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 7, 2021, 9:33 PM MDT (03:33 UTC)
Expired
Jul 7, 2021, 10:00 PM MDT
In force
27 min
Issued by
NWS Great Falls, MT

County Glacier County, MT

The radar

The Great Falls radar (KTFX), 199 km from the middle of the area, began a volume at 03:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 3.6 hours before the alert went out and 239 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Great_falls, MT at 00:00Z on 2021-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 00:00Z on 2021-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 301 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
17 J/kg
Mixed-layer CIN
-372 J/kg
Mixed-layer LCL
2303 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
301 m²/s²
0-3 km storm-relative helicity
511 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

<!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>

What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Great Falls, MT wrote its last area forecast discussion before this special weather statement went out at Jul 7, 9:27 PM MDT, 6 minutes earlier.

Area forecast discussion, Jul 7, 9:27 PM MDT, 6 minutes before
<!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>

In the hours before

Special weather statement, Jul 7, 6:56 PM MDT, 2 hours 37 minutes before
Special Weather Statement
National Weather Service Great Falls MT
656 PM MDT Wed Jul 7 2021

MTZ051-080130-
Fergus-
656 PM MDT Wed Jul 7 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN FERGUS COUNTY...

At 655 PM MDT, a strong thunderstorm was located 20 miles south of
Zortman, moving southeast at 25 mph.

Wind gusts up to 50 mph and half inch hail are possible with this
storm.

This storm will remain over mainly rural areas of northeastern Fergus
County.

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.

To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in Great Falls.

LAT...LON 4760 10869 4762 10866 4763 10861 4761 10857
      4762 10851 4760 10850 4761 10844 4758 10842
      4760 10840 4757 10834 4758 10831 4735 10832
TIME...MOT...LOC 0055Z 308DEG 23KT 4763 10848

Kredensor
Local storm report, Jul 7, 7:00 PM MDT, 2 hours 33 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
700 PM MDT WED JUL 7 2021

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

0645 PM     HAIL             25 NE ROY               47.62N 108.62W
07/07/2021  E0.50 INCH       FERGUS             MT   TRAINED SPOTTER

            TRAINED SPOTTER REPORTED HALF INCH HAIL AND
            ESTIMATED WIND GUSTS OF 45 MPH.

&&

HART
Local storm report, Jul 7, 7:23 PM MDT, 2 hours 10 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
723 PM MDT WED JUL 7 2021

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

0525 PM     HEAVY RAIN       5 SW WINDHAM            47.04N 110.22W
07/07/2021  M1.20 INCH       JUDITH BASIN       MT   TRAINED SPOTTER

&&
Special weather statement, Jul 7, 8:02 PM MDT, 1 hour 31 minutes before
Special Weather Statement
National Weather Service Great Falls MT
802 PM MDT Wed Jul 7 2021

MTZ009-010-080230-
Northern Rocky Mountain Front-Eastern Glacier-
802 PM MDT Wed Jul 7 2021

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN GLACIER
COUNTY...

At 801 PM MDT, strong thunderstorms were clustered 20 miles north of
West Glacier, or 41 miles north of Evergreen, moving northeast at 40
mph.

Winds in excess of 40 mph and pea size hail are possible with these
storms.

Locations impacted include...
Many Glacier, Babb, Saint Mary, Goat Haunt, Logan Pass and Starr
School.

This includes Highway 89 between mile markers 19 and 50.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

LAT...LON 4900 11317 4860 11282 4864 11375 4869 11374
      4870 11371 4878 11377 4882 11376 4885 11384
      4883 11399 4886 11400 4889 11406 4892 11401
      4894 11405 4896 11403 4899 11407
TIME...MOT...LOC 0201Z 245DEG 49KT 4880 11400

RCG
Special weather statement, Jul 7, 8:48 PM MDT, 45 minutes before
Special Weather Statement
National Weather Service Great Falls MT
848 PM MDT Wed Jul 7 2021

MTZ009-010-080315-
Northern Rocky Mountain Front-Eastern Glacier-
848 PM MDT Wed Jul 7 2021

...AN AREA OF THUNDERSTORMS WILL AFFECT GLACIER COUNTY...

At 847 PM MDT, thunderstorms were clustered 26 miles northeast of
West Glacier, or 49 miles northeast of Evergreen, moving northeast
at 35 mph.

Winds up to 40 mph and pea size hail are possible with this storm.

Locations impacted include...
Browning, East Glacier Park Village, North Browning, Kiowa, South
Browning, East Glacier Park, Many Glacier, Babb, Marias Pass, Logan
Pass, Starr School, Goat Haunt, Santa Rita and Saint Mary.

This includes the following highways...
 Highway 2 between mile markers 198 and 248.
 Highway 89 between mile markers 1 and 50, and between mile markers
104 and 110.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

LAT...LON 4900 11220 4868 11233 4829 11333 4833 11338
      4837 11334 4842 11335 4842 11340 4846 11348
      4855 11347 4862 11375 4873 11371 4884 11378
      4885 11391 4882 11395 4889 11406 4891 11401
      4900 11406
TIME...MOT...LOC 0247Z 240DEG 49KT 4882 11367

RCG
Special weather statement, Jul 7, 9:33 PM MDT, 0 minutes before
<!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>

The office that day

Everything else NWS Great Falls, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 7, 6:10 PM MDTSevere Thunderstorm WarningTFXFergus, Judith Basin35 min
Jul 7, 6:36 PM MDTSpecial Weather StatementTFX24 min
Jul 7, 6:56 PM MDTSpecial Weather StatementTFXPetroleum34 min
Jul 7, 8:02 PM MDTSpecial Weather StatementTFXGlacier28 min
Jul 7, 8:48 PM MDTSpecial Weather StatementTFXGlacier27 min
Jul 8, 11:48 AM MDTSpecial Weather StatementTFXBlaine42 min

Nearby

Special Weather Statements in Montana, 2021Every special weather statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.