Alert archive / Montana / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 69, NWS Glasgow, MT

July 20, 2013Dawson County, McCone County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Jul 20, 2013, 6:40 PM MDT for Dawson County, McCone County, Montana. It was in force for 65 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 20, 2013, 6:40 PM MDT (00:40 UTC)
Expired: Jul 20, 2013, 7:45 PM MDT
In force: 65 min
Issued by: NWS Glasgow, MT
Area: Storm-based polygon

Counties Dawson County, MT, McCone County, MT

The radar

The Glasgow radar (KGGW), 127 km from the middle of the area, began a volume at 00:40 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.7 hours before the alert went out and 126 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: 48 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 2363 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 113 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

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 Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 20, 4:22 PM MDT, 2 hours 18 minutes earlier.

Area forecast discussion, Jul 20, 4:22 PM MDT, 2 hours 18 minutes before

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Hazardous weather outlook, Jul 20, 4:49 PM MDT, 1 hour 51 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
449 PM MDT SAT JUL 20 2013

MTZ016>027-059>062-211100-
CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE-
RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS-
SOUTHWEST PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT-
449 PM MDT SAT JUL 20 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND TONIGHT...
MOSTLY NEAR THE CANADIAN AND NORTH DAKOTA BORDERS. STRONGER STORMS
WILL LIKELY HAVE SOME BRIEF HEAVY RAIN...SMALL HAIL...GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A COLD FRONT MOVING THROUGH THE REGION ON SUNDAY WILL GENERATE
GUSTY NORTHWEST WIND. THEREFORE A LAKE WIND ADVISORY IS IN EFFECT
FOR FORT PECK LAKE FROM NOON UNTIL 9 PM SUNDAY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

In the hours before

Special weather statement, Jul 20, 5:31 PM MDT, 1 hour 9 minutes before

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Local storm report, Jul 20, 5:42 PM MDT, 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
542 PM MDT SAT JUL 20 2013

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

0535 PM     HAIL             4 N OSWEGO              48.11N 105.89W
07/20/2013  E0.88 INCH       VALLEY             MT   TRAINED SPOTTER

            SPOTTER ON THE EDGE OF THE STORM REPORTED PEA AND NICKEL
            SIZED HAIL.

&&

MATTM

Local storm report, Jul 20, 6:02 PM MDT, 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
602 PM MDT SAT JUL 20 2013

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

0545 PM     HAIL             4 N OSWEGO              48.11N 105.89W
07/20/2013  E1.00 INCH       VALLEY             MT   TRAINED SPOTTER

&&

MATTM

Special weather statement, Jul 20, 6:02 PM MDT, 38 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
602 PM MDT SAT JUL 20 2013

MTZ020-023-024-210100-
MCCONE-RICHLAND-ROOSEVELT-
602 PM MDT SAT JUL 20 2013

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

SIGNIFICANT WEATHER ADVISORY FOR...
  WESTERN ROOSEVELT COUNTY IN NORTHEAST MONTANA...
  NORTHWESTERN RICHLAND COUNTY IN NORTHEAST MONTANA...
  NORTHEASTERN MCCONE COUNTY IN NORTHEAST MONTANA...

UNTIL 700 PM MDT.

AT 559 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 13 MILES SOUTHWEST OF BREDETTE...MOVING SOUTHEAST
AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS IN THE ADVISORY INCLUDE...
   POPLAR...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4813 10498 4811 10498 4809 10495 4810 10493
      4806 10487 4790 10520 4825 10553 4838 10559
      4844 10540
TIME...MOT...LOC 0002Z 323DEG 19KT 4834 10544

CAMPBELL
WEATHER.GOV/GLASGOW

Special weather statement, Jul 20, 6:07 PM MDT, 33 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
607 PM MDT SAT JUL 20 2013

MTZ017-020-210045-
ROOSEVELT-VALLEY-
607 PM MDT SAT JUL 20 2013

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

SIGNIFICANT WEATHER ADVISORY FOR...
  EASTERN VALLEY COUNTY IN NORTHEAST MONTANA...
  SOUTHWESTERN ROOSEVELT COUNTY IN NORTHEAST MONTANA...

UNTIL 645 PM MDT.

AT 605 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 12 MILES WEST OF LUSTRE...MOVING SOUTHEAST AT 25
MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS IN THE ADVISORY INCLUDE...
  RURAL AREAS OF EASTERN VALLEY COUNTY...
  RURAL AREAS OF WESTERN ROOSEVELT COUNTY...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4842 10609 4812 10560 4804 10577 4805 10577
      4802 10579 4801 10585 4804 10590 4801 10590
      4833 10621
TIME...MOT...LOC 0007Z 318DEG 22KT 4832 10611

CAMPBELL
WEATHER.GOV/GLASGOW

Local storm report, Jul 20, 6:40 PM MDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
640 PM MDT SAT JUL 20 2013

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

0637 PM     HAIL             5 S VIDA                47.76N 105.49W
07/20/2013  E1.00 INCH       MCCONE             MT   TRAINED SPOTTER

            DIME TO QUARTER SIZED HAIL WITH 20 TO 30 MPH WINDS AND
            MODERATE RAIN REDUCING VISIBILITY TO ONE HALF MILE.

&&

MATTM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 6:02 PM MDT	Special Weather Statement	GGW	Roosevelt	58 min
Jul 20, 6:07 PM MDT	Special Weather Statement	GGW		38 min
Jul 20, 6:57 PM MDT	Tornado Warning	GGW	Dawson, McCone	33 min
Jul 20, 7:25 PM MDT	Tornado Warning	GGW	Dawson	35 min
Jul 20, 7:39 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, Prairie	51 min
Jul 20, 7:43 PM MDT	Tornado Warning	GGW	Dawson	32 min
Jul 20, 8:29 PM MDT	Tornado Warning	GGW	Dawson, Prairie	31 min
Jul 20, 8:57 PM MDT	Severe Thunderstorm Warning	GGW	Prairie	48 min

Nearby

Severe Thunderstorm Warnings in Montana, 2013 Every severe thunderstorm warning in 2013

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.