Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 11, NWS Missoula, MT

July 12, 2001Powell County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 12, 2001, 2:23 PM MDT for Powell County, Montana. It was in force for 52 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Jul 12, 2001, 2:23 PM MDT (20:23 UTC)
Expired
Jul 12, 2001, 3:15 PM MDT
In force
52 min
Issued by
NWS Missoula, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Powell County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.4 hours before the alert went out and 185 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 12:00Z on 2001-07-12Temperature 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, Great_falls, MT at 12:00Z on 2001-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2375 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KMSO 122024
SVRMSO

MTC077-122115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
223 PM MDT THU JUL 12 2001

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL POWELL COUNTY IN WEST CENTRAL MONTANA

* UNTIL 315 PM MDT

* AT 223 PM MDT...RADAR INDICATED A SEVERE THUNDERSTORM 7 MILES WEST
  OF GARRISON...OR 13 MILES NORTHWEST OF DEER LODGE...MOVING
  NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  4 MILES NORTHWEST OF GARRISON AT 230 PM MDT

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS AND HAIL...ALONG WITH
FREQUENT LIGHTNING AND HEAVY RAIN. FOR YOUR PROTECTION...GO INDOORS
AND STAY AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A
WELL PROTECTED AREA.


LAT...LON 4689 11268 4656 11303 4641 11302 4671 11242

HARMER

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 Missoula, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 12, 10:00 AM MDT, 4 hours 23 minutes earlier.

Area forecast discussion, Jul 12, 10:00 AM MDT, 4 hours 23 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1000 AM MDT THU JUL 12 2001

NO UPDATES AT THIS TIME. SOUTHWEST FLOW OVER THE CWA WITH SEVERAL
WEAK SHORT WAVES MOVING ACROSS THE AREA. EXPECT
SHOWERS/THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON. SPC HAS
ENTIRE CWA UNDER A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY.
LOOKING AT THE 12Z ETA IT APPEARS THE BEST CHANCE OF STRONG
THUNDERSTORMS WILL BE ACROSS THE SOUTHEASTERN ZONES. KOLATA

.MSO...FIRE WEATHER WATCH TODAY FOR FIRE WEATHER ZONE 104.

In the hours before

Special weather statement, Jul 12, 10:30 AM MDT, 3 hours 53 minutes before
IDZ009-010-MTZ006-007-122215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
1025 AM MDT (925 AM PDT) THU JUL 12 2001

...STRONG THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING OVER
RAVALLI...GRANITE...DEER LODGE AND SILVER BOW COUNTIES IN MONTANA
AND LEMHI COUNTY IN IDAHO...

STRONG THUNDERSTORMS PRODUCING STRONG GUSTY WINDS AND HAIL ARE
POSSIBLE OVER SOUTHWEST MONTANA WEST OF THE CONTINENTAL DIVIDE...AND
IN LEMHI COUNTY IN IDAHO THIS AFTERNOON AND EVENING.

THUNDERSTORMS WILL OCCUR ELSEWHERE...BUT ARE NOT EXPECTED TO BE AS
STRONG AS THOSE IN THESE AREAS.

THE ATMOSPHERE REMAINS VERY UNSTABLE TODAY...AND A WEAK UPPER LEVEL
DISTURBANCE PASSING OVER NORTH CENTRAL IDAHO AND SOUTHWEST MONTANA
THIS AFTERNOON AND EVENING...WILL TRIGGER SCATTERED STRONG
THUNDERSTORMS INTO THE EVENING HOURS.

STAY TUNED FOR FURTHER UPDATES ON THUNDERSTORM DEVELOPMENT THIS
AFTERNOON AND EVENING.

FELSCH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 6:10 PM MDTSevere Thunderstorm WarningMSOMissoula50 min
Jul 12, 4:36 PM MDTFlash Flood WarningMSOGranite, Ravalli114 min
Jul 12, 5:16 PM MDTSevere Thunderstorm WarningMSODeer Lodge, Granite, Powell59 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001Every severe thunderstorm warning in 2001

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.