Alert archive / Montana / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 11, NWS Great Falls, MT

May 12, 2007Liberty County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at May 12, 2007, 6:22 PM MDT for Liberty County, Montana. It was in force for 23 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
May 12, 2007, 6:22 PM MDT (00:22 UTC)
Expired
May 12, 2007, 6:45 PM MDT
In force
23 min
Issued by
NWS Great Falls, MT
Area
Counties, with a storm outline in the text

County Liberty County, MT

The radar

The Great Falls radar (KTFX), 125 km from the middle of the area, began a volume at 00:23 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, 0.4 hours before the alert went out and 127 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 2007-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 2007-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.193958Sfc1 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
7 J/kg
Mixed-layer CIN
-155 J/kg
Mixed-layer LCL
2492 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
325 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 May 12, 5:20 PM MDT, 1 hour 2 minutes earlier.

Area forecast discussion, May 12, 5:20 PM MDT, 1 hour 2 minutes before
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Hazardous weather outlook, May 12, 2:40 PM MDT, 3 hours 42 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
240 PM MDT SAT MAY 12 2007

MTZ011>014-047>055-132045-
HILL-CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-BLAINE-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS-
JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
240 PM MDT SAT MAY 12 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND NORTH CENTRAL
MONTANA LATE THIS AFTERNOON AND EVENING. SOME OF THE STORMS WILL
BECOME SEVERE...PRODUCING LARGE HAIL. ALONG WITH THE LARGE HAIL...A
FEW OF THE SEVERE STORMS MAY PRODUCE DAMAGING WIND GUSTS. A SEVERE
THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 PM.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A PACIFIC WEATHER SYSTEM WILL MOVE INTO THE AREA FOR SUNDAY
THROUGH MONDAY. THIS SYSTEM WILL BRING COOLER AND MORE MOIST AIR
INTO THE AREA FOR A BETTER CHANCE OF PRECIPITATION...BUT LESS OF A
CHANCE FOR THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

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

MTZ008-015-132045-
BEAVERHEAD-MADISON-
240 PM MDT SAT MAY 12 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST MONTANA LATE THIS
AFTERNOON. SOME OF THE STORMS WILL BE STRONG...PRODUCING SMALL
HAIL AND GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A PACIFIC WEATHER SYSTEM WILL MOVE INTO THE AREA FOR SUNDAY
THROUGH MONDAY. THIS SYSTEM WILL BRING COOLER AND MORE MOIST AIR
INTO THE AREA FOR A BETTER CHANCE OF PRECIPITATION...BUT LESS OF A
CHANCE FOR THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

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

MTZ009-010-044>046-132045-
NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-TOOLE-LIBERTY-
EASTERN PONDERA-
240 PM MDT SAT MAY 12 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL DEVELOP OVER NORTHERN MONTANA LATE THIS
AFTERNOON AND THIS EVENING. SOME OF THE STORMS WILL BE
STRONG...PRODUCING SMALL HAIL AND GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A PACIFIC WEATHER SYSTEM WILL MOVE INTO THE AREA FOR SUNDAY
THROUGH MONDAY. THIS SYSTEM WILL BRING COOLER AND MORE MOIST AIR
INTO THE AREA FOR A BETTER CHANCE OF PRECIPITATION...BUT LESS OF A
CHANCE FOR THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Local storm report, May 12, 5:42 PM MDT, 40 minutes before
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Local storm report, May 12, 5:48 PM MDT, 34 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
548 PM MDT SAT MAY 12 2007

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

0535 PM     HAIL             LEWISTOWN               47.06N 109.43W
05/12/2007  E0.25 INCH       FERGUS             MT   TRAINED SPOTTER

            PEA SIZE HAIL FALLING IN THE LEWISTOWN AREA.

&&

BRUSDA
Local storm report, May 12, 5:57 PM MDT, 25 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
557 PM MDT SAT MAY 12 2007

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

0556 PM     HEAVY RAIN       STANFORD                47.15N 110.22W
05/12/2007  M1.00 INCH       JUDITH BASIN       MT   TRAINED SPOTTER

&&

SAUCIER

The office that day

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

IssuedProductOfficeCountiesLasted
May 13, 2:48 PM MDTSevere Thunderstorm WarningTFXJudith Basin18 min
May 13, 3:18 PM MDTSevere Thunderstorm WarningTFXGallatin42 min

Nearby

Severe Thunderstorm Warnings in Montana, 2007Every severe thunderstorm warning in 2007

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.