Alert archive / Montana / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 12, NWS Great Falls, MT

July 2, 2009Broadwater County, Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 2, 2009, 3:57 PM MDT for Broadwater County, Gallatin County, Montana. It was in force for 63 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 2, 2009, 3:57 PM MDT (21:57 UTC)
Expired: Jul 2, 2009, 5:00 PM MDT
In force: 63 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon

Counties Broadwater County, MT, Gallatin County, MT

The radar

The Great Falls radar (KTFX), 169 km from the middle of the area, began a volume at 22:00 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

Riverton, WY (KRIW), launched 12:00Z, 10.0 hours before the alert went out and 395 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1511 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: -24 m²/s²
0-3 km storm-relative helicity: 69 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 2, 3:28 PM MDT, 29 minutes earlier.

Area forecast discussion, Jul 2, 3:28 PM MDT, 29 minutes before

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Hazardous weather outlook, Jul 2, 3:41 PM MDT, 16 minutes before

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In the hours before

Special weather statement, Jul 2, 1:07 PM MDT, 2 hours 50 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
107 PM MDT THU JUL 2 2009

MTZ014-052-021930-
CENTRAL AND SOUTHERN LEWIS AND CLARK MT-JEFFERSON MT-
107 PM MDT THU JUL 2 2009

...SIGNIFICANT WEATHER ADVISORY FOR EXTREME SOUTHERN LEWIS AND CLARK
AND NORTHERN JEFFERSON COUNTIES UNTIL 130 PM MDT...

AT 104 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 7 MILES NORTH OF BASIN...OR 11 MILES NORTHWEST OF
BOULDER...MOVING NORTHEAST AT 10 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND HEAVY RAINFALL IS EXPECTED
WITH THIS STORM.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

LAT...LON 4639 11236 4647 11232 4659 11209 4635 11189
      4621 11232 4639 11240
TIME...MOT...LOC 1906Z 244DEG 7KT 4638 11224

BRW

Special weather statement, Jul 2, 1:34 PM MDT, 2 hours 23 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
134 PM MDT THU JUL 2 2009

MTZ050-051-022015-
FERGUS MT-JUDITH BASIN MT-
134 PM MDT THU JUL 2 2009

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL JUDITH BASIN AND WESTERN
FERGUS COUNTIES UNTIL 215 PM MDT...

AT 131 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR STANFORD...MOVING NORTHEAST AT 15 MPH.

HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...DENTON.

IN ADDITION...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.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

LAT...LON 4741 10991 4720 10970 4701 11020 4716 11035
TIME...MOT...LOC 1933Z 235DEG 14KT 4714 11016

Special weather statement, Jul 2, 2:17 PM MDT, 1 hour 40 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
217 PM MDT THU JUL 2 2009

MTZ050-051-022100-
FERGUS MT-JUDITH BASIN MT-
217 PM MDT THU JUL 2 2009

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN JUDITH BASIN AND
CENTRAL FERGUS COUNTIES UNTIL 300 PM MDT...

AT 215 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
AN AREA OF STRONG THUNDERSTORM NEAR DENTON...OR 13 MILES NORTHEAST
OF STANFORD...MOVING NORTHEAST AT 25 MPH.

EXPECT HAIL UP TO ONE-HALF INCH IN DIAMETER...WIND GUSTS UP TO
40 MPH...A PERIOD OF VERY HEAVY RAIN AND FREQUENT LIGHTNING AS THE
STORM MOVES THROUGH. ACCORDING TO RADAR ESTIMATES...THIS STORM IS
CAPABLE OF PRODUCING OVER ONE INCH OF RAIN IN LESS THAN 30 MINUTES.

* LOCATIONS IMPACTED INCLUDE...
   DENTON...
   LEWISTOWN...
   HILGER...

LAT...LON 4767 10930 4710 10880 4688 10967 4714 10989
      4711 11022 4728 11040
TIME...MOT...LOC 2014Z 230DEG 20KT 4729 11002

Local storm report, Jul 2, 2:30 PM MDT, 1 hour 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
230 PM MDT THU JUL 02 2009

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

0228 PM     HAIL             BOULDER                 46.24N 112.12W
07/02/2009  E0.50 INCH       JEFFERSON          MT   TRAINED SPOTTER

            ESTIMATED HALF INCH HAIL FALLING.

&&

BRUSDA

Local storm report, Jul 2, 2:42 PM MDT, 1 hour 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
242 PM MDT THU JUL 02 2009

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

0230 PM     HAIL             BOULDER                 46.24N 112.12W
07/02/2009  E0.88 INCH       JEFFERSON          MT   TRAINED SPOTTER

            NICKEL SIZE HAIL FALLING IN BOULDER.

&&

BRUSDA

Local storm report, Jul 2, 3:09 PM MDT, 48 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 1:07 PM MDT	Special Weather Statement	TFX	Judith Basin	38 min
Jul 2, 1:34 PM MDT	Special Weather Statement	TFX	Judith Basin	41 min
Jul 2, 2:17 PM MDT	Special Weather Statement	TFX	Fergus	43 min
Jul 2, 2:52 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Fergus	53 min
Jul 2, 3:07 PM MDT	Severe Thunderstorm Warning	TFX	Broadwater, Jefferson	53 min
Jul 2, 3:11 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	64 min
Jul 2, 3:46 PM MDT	Severe Thunderstorm Warning	TFX	Blaine, Chouteau	59 min
Jul 2, 4:09 PM MDT	Special Weather Statement	TFX	Musselshell	36 min
Jul 2, 4:13 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	22 min
Jul 2, 5:10 PM MDT	Special Weather Statement	TFX	Blaine	50 min
Jul 2, 5:11 PM MDT	Special Weather Statement	TFX	Fergus	49 min

Nearby

Severe Thunderstorm Warnings in Montana, 2009 Every severe thunderstorm warning in 2009

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.