Alert archive / Montana / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 37, NWS Great Falls, MT

July 7, 20204 counties in Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 7, 2020, 3:13 PM MDT for 4 counties in Montana. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 7, 2020, 3:13 PM MDT (21:13 UTC)
Expired: Jul 7, 2020, 3:45 PM MDT
In force: 32 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Blaine County, MT, Chouteau County, MT, Fergus County, MT, Judith Basin County, MT

The radar

The Great Falls radar (KTFX), 127 km from the middle of the area, began a volume at 21:16 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 7, 1:14 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 9.2 hours before the alert went out and 69 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 632 J/kg
Mixed-layer CIN: -264 J/kg
Mixed-layer LCL: 1637 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 265 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Jul 7, 2:44 PM MDT, 29 minutes earlier.

Area forecast discussion, Jul 7, 2:44 PM MDT, 29 minutes before

Area Forecast Discussion
National Weather Service Great Falls MT
244 PM MDT Tue Jul 7 2020

.SYNOPSIS...
Thunderstorms will exit Central MT this evening, as cooler air
moves into the region for Wednesday. A warming trend is expected
from Thursday into the weekend, with afternoon temperatures
averaging about 5 to 10 degrees above normal on Saturday. The next
chance for storms is on Friday, as a quick moving upper level
disturbance moves through the region.

&&

.DISCUSSION...
Tonight through Thursday...Severe storms continue to push eastward
through the region. The main threat will be large hail and
damaging winds. An isolated tornado, mainly east of a line from
Havre to Stanford would be possible. Most severe storms should
exit our region by 7 PM or so. It turns a bit cooler on Wednesday,
but warmer air returns on Thursday.

Friday through Tuesday...There will be a chance for showers on
Friday, as an upper level disturbance moves through. The main
concern over the weekend and into early next week will be the
potential for warmer temperatures over the weekend /increase
winds. Wind speeds could approach high wind warning criteria from
Sunday into Monday over North Central MT. Temperatures do start to
cool a bit below normal by next Mon/Tue. Brusda

&&

.AVIATION...
Updated 1155 AM MDT Tue Jul 7 2020 (18Z TAF Period)

A cold front will move from west to east across the region this
afternoon. Thunderstorms, some with hail/strong winds will likely
accompany the front. An isolated tornado is possible across Central
MT. The storms exit our region generally by 01z Wednesday. Generally
VFR conditions expected overnight and into the day Wednesday. Brusda

For more detailed aviation weather and hazard information, please
see: weather.gov/zlc

NOTE: Amendments not scheduled for Ennis (KEKS) due to ongoing
runway closure.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  51  72  46  81 /   0   0   0   0
CTB  52  68  45  77 /   0  10   0   0
HLN  48  73  46  81 /   0   0   0   0
BZN  46  76  44  83 /  10   0   0  10
WYS  38  70  38  76 /  50   0   0   0
DLN  44  74  43  81 /   0   0   0  10
HVR  53  73  49  81 /  10  10   0   0
LWT  47  70  46  78 /   0   0   0   0

&&

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

&&

http://www.weather.gov/greatfalls

In the hours before

Local storm report, Jul 7, 2:33 PM MDT, 40 minutes before

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Local storm report, Jul 7, 2:36 PM MDT, 37 minutes before

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Local storm report, Jul 7, 2:38 PM MDT, 35 minutes before

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  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <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.
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Local storm report, Jul 7, 2:51 PM MDT, 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
251 PM MDT TUE JUL 7 2020

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

0250 PM     HAIL             20 N INVERNESS          48.85N 110.69W
07/07/2020  M0.70 INCH       HILL               MT   TRAINED SPOTTER

            HALF INCH OF RAIN IN 15 MINUTES.

&&

JAA

Local storm report, Jul 7, 3:02 PM MDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
302 PM MDT TUE JUL 7 2020

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

0255 PM     HAIL             3 SE DENTON             47.29N 109.91W
07/07/2020  E1.50 INCH       FERGUS             MT   TRAINED SPOTTER

            FEW PING PONG BALL SIZE HAIL STONES.

&&

SLA

Special weather statement, Jul 7, 3:10 PM MDT, 3 minutes before

Special Weather Statement
National Weather Service Great Falls MT
310 PM MDT Tue Jul 7 2020

MTZ015-054-055-072200-
Madison MT-Gallatin MT-Meagher MT-
310 PM MDT Tue Jul 7 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN MEAGHER...NORTHEASTERN
MADISON AND GALLATIN COUNTIES UNTIL 400 PM MDT...

At 310 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 10 miles north of Manhattan to 12 miles
northwest of Crescent Lake. Movement was northeast at 40 mph.

Penny size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Bozeman, Belgrade, Manhattan, Big Sky, Logan, Maudlow, Four Corners,
Amsterdam, Bozeman Hot Springs, Gallatin Gateway, Church Hill and
Menard.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

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

&&

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
south central and central Montana.

LAT...LON 4509 11130 4587 11144 4611 11130 4624 11073
      4620 11072 4619 11078 4560 11080 4559 11086
      4553 11086 4552 11092 4536 11092 4535 11104
      4514 11104
TIME...MOT...LOC 2110Z 203DEG 37KT 4601 11127 4519 11119

JANGLIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 6:59 AM MDT	Special Weather Statement	TFX	Glacier	31 min
Jul 7, 7:15 AM MDT	Special Weather Statement	TFX	Glacier	30 min
Jul 7, 7:47 AM MDT	Special Weather Statement	TFX	Glacier	28 min
Jul 7, 11:30 AM MDT	Special Weather Statement	TFX	Madison	45 min
Jul 7, 11:36 AM MDT	Special Weather Statement	TFX	Broadwater	24 min
Jul 7, 12:39 PM MDT	Special Weather Statement	TFX	Cascade	51 min
Jul 7, 12:40 PM MDT	Special Weather Statement	TFX	Broadwater	35 min
Jul 7, 12:53 PM MDT	Special Weather Statement	TFX	Gallatin	37 min
Jul 7, 1:10 PM MDT	Special Weather Statement	TFX	Meagher	35 min
Jul 7, 1:27 PM MDT	Special Weather Statement	TFX	Chouteau	33 min
Jul 7, 1:27 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin	33 min
Jul 7, 1:28 PM MDT	Severe Thunderstorm Warning	TFX	Broadwater, Gallatin, Meagher	32 min
Jul 7, 1:35 PM MDT	Special Weather Statement	TFX	Madison	25 min
Jul 7, 1:43 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau	47 min
Jul 7, 1:48 PM MDT	Special Weather Statement	TFX	Hill	27 min
Jul 7, 1:52 PM MDT	Special Weather Statement	TFX	Liberty	38 min
Jul 7, 1:56 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	18 min
Jul 7, 2:04 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin, Madison	26 min
Jul 7, 2:13 PM MDT	Severe Thunderstorm Warning	TFX	Hill, Liberty	47 min
Jul 7, 2:29 PM MDT	Special Weather Statement	TFX	Gallatin	31 min
Jul 7, 2:31 PM MDT	Severe Thunderstorm Warning	TFX	Blaine, Chouteau, Hill	59 min
Jul 7, 2:43 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Fergus, Judith Basin	32 min
Jul 7, 3:10 PM MDT	Special Weather Statement	TFX	Gallatin	50 min
Jul 7, 3:30 PM MDT	Special Weather Statement	TFX	Blaine	45 min
Jul 7, 3:33 PM MDT	Tornado Warning	TFX	Fergus	27 min
Jul 7, 3:44 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	46 min
Jul 7, 3:55 PM MDT	Tornado Warning	TFX	Fergus	20 min
Jul 7, 4:04 PM MDT	Special Weather Statement	TFX	Gallatin	26 min
Jul 7, 4:09 PM MDT	Special Weather Statement	TFX	Blaine	36 min
Jul 7, 4:14 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	46 min
Jul 7, 4:21 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	9 min
Jul 7, 4:38 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	21 min
Jul 7, 4:56 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	17 min
Jul 7, 5:38 PM MDT	Special Weather Statement	TFX		22 min

Nearby

Severe Thunderstorm Warnings in Montana, 2020 Every severe thunderstorm warning in 2020

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.