Alert archive / Montana / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 17, NWS Great Falls, MT

May 19, 2007Chouteau County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at May 19, 2007, 7:13 PM MDT for Chouteau County, Montana. It was in force for 47 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 19, 2007, 7:13 PM MDT (01:13 UTC)
Expired
May 19, 2007, 8:00 PM MDT
In force
47 min
Issued by
NWS Great Falls, MT
Area
Counties, with a storm outline in the text

County Chouteau County, MT

The radar

The Great Falls radar (KTFX), 85 km from the middle of the area, began a volume at 01:13 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.

IssuedProductOfficeLasted
May 19, 2:36 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.2 hours before the alert went out and 288 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, Glasgow Intl Airport, MT at 00:00Z on 2007-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Glasgow Intl Airport, MT at 00:00Z on 2007-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1211 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 19, 5:35 PM MDT, 1 hour 38 minutes earlier.

Area forecast discussion, May 19, 5:35 PM MDT, 1 hour 38 minutes before
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Hazardous weather outlook, May 19, 2:47 PM MDT, 4 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
247 PM MDT SAT MAY 19 2007

MTZ008-015-052-202100-
BEAVERHEAD-MADISON-JEFFERSON-
247 PM MDT SAT MAY 19 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

INCREASING MOISTURE AND INSTABILITY TODAY FOR INCREASING CHANCE
OF THUNDERSTORMS. SOME OF THESE STORMS COULD BE SEVERE WITH HAIL
AND GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY NIGHT THROUGH TUESDAY WILL SEE AN UPPER LEVEL SYSTEM MOVE
THROUGH THE AREA. THIS SYSTEM WILL BRING COOLER TEMPERATURES AND A GOOD
CHANCE OF PRECIPITATION. ACCUMULATING SNOW IS POSSIBLE OVER THE
MOUNTAINS AND HIGHER TERRAIN.

.SPOTTER INFORMATION STATEMENT...

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

MTZ012-013-050-051-053>055-202100-
CASCADE-CHOUTEAU-JUDITH BASIN-FERGUS-BROADWATER-MEAGHER-GALLATIN-
247 PM MDT SAT MAY 19 2007

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10 PM THIS
SATURDAY EVENING. INCREASING MOISTURE AND INSTABILITY WILL PRODUCE
AN INCREASING CHANCE OF THUNDERSTORMS. SOME OF THESE THUNDERSTORMS
WILL BE SEVERE WITH LARGE HAIL AND STRONG GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY NIGHT THROUGH TUESDAY WILL SEE AN UPPER LEVEL SYSTEM MOVE
THROUGH THE AREA. THIS SYSTEM WILL BRING COOLER TEMPERATURES AND A GOOD
CHANCE OF PRECIPITATION. ACCUMULATING SNOW IS POSSIBLE OVER THE
MOUNTAINS AND HIGHER TERRAIN.

.SPOTTER INFORMATION STATEMENT...

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

MTZ009-010-014-046-048-049-202100-
NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-
CENTRAL AND SOUTHERN LEWIS AND CLARK-EASTERN PONDERA-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-
247 PM MDT SAT MAY 19 2007

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

INCREASING MOISTURE AND INSTABILITY TODAY WILL INCREASE CHANCES OF
THUNDERSTORMS. SOME OF THESE STORMS COULD BE SEVERE WITH HAIL AND
GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY NIGHT THROUGH TUESDAY WILL SEE AN UPPER LEVEL SYSTEM MOVE
THROUGH THE AREA. THIS SYSTEM WILL BRING COOLER TEMPERATURES AND A GOOD
CHANCE OF PRECIPITATION. ACCUMULATING SNOW IS POSSIBLE OVER THE
MOUNTAINS AND HIGHER TERRAIN.

.SPOTTER INFORMATION STATEMENT...

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

MTZ011-044-045-047-202100-
HILL-TOOLE-LIBERTY-BLAINE-
247 PM MDT SAT MAY 19 2007

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

INCREASING MOISTURE AND INSTABILITY TODAY FOR INCREASING CHANCE OF
THUNDERSTORMS. SOME OF THESE STORMS COULD BE SEVERE WITH HAIL AND
GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY NIGHT THROUGH TUESDAY WILL SEE AN UPPER LEVEL SYSTEM MOVE
THROUGH THE AREA. THIS SYSTEM WILL BRING COOLER TEMPERATURES AND A GOOD
CHANCE OF PRECIPITATION. ACCUMULATING SNOW IS POSSIBLE OVER SOME
OF THE HIGHER TERRAIN.

.SPOTTER INFORMATION STATEMENT...

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

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 4:45 AM MDTWinter Storm WatchTFX23 hr

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.