Alert archive / Montana / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 21, NWS Billings, MT

August 2, 2012Carter County, Custer County, Fallon County, Montana

NWS Billings, MT issued this severe thunderstorm warning at Aug 2, 2012, 1:59 PM MDT for Carter County, Custer County, Fallon County, Montana. It was in force for 59 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 2, 2012, 1:59 PM MDT (19:59 UTC)
Expired
Aug 2, 2012, 2:58 PM MDT
In force
59 min
Issued by
NWS Billings, MT
Area
Storm-based polygon

Counties Carter County, MT, Custer County, MT, Fallon County, MT

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 8.0 hours before the alert went out and 269 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, Rapid City, SD at 12:00Z on 2012-08-02Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2012-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -120 square meters per square second.1939587897Sfc1 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
2040 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-120 m²/s²
0-3 km storm-relative helicity
-117 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.

926 
WUUS55 KBYZ 021959
SVRBYZ
MTC011-017-025-022100-
/O.NEW.KBYZ.SV.W.0021.120802T1959Z-120802T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BILLINGS MT
159 PM MDT THU AUG 2 2012

THE NATIONAL WEATHER SERVICE IN BILLINGS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN CARTER COUNTY IN SOUTHEAST MONTANA...
  SOUTHEASTERN CUSTER COUNTY IN SOUTHEAST MONTANA...
  WEST CENTRAL FALLON COUNTY IN SOUTHEAST MONTANA...

* UNTIL 300 PM MDT.

* AT 154 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS WITH HALF DOLLAR SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED     
  ALONG A LINE EXTENDING FROM 34 MILES SOUTHEAST OF MILES CITY TO    
  30 MILES WEST OF EKALAKA TO 28 MILES NORTH OF BROADUS...AND MOVING 
  EAST AT 20 MPH. THE STRONGEST STORM WAS ON THE SOUTHERN END OF THE 
  LINE IN SOUTHEAST CUSTER COUNTY. 

* SEVERE THUNDERSTORMS WILL BE NEAR...
  RURAL SOUTHEASTERN CUSTER COUNTY AT 210 PM MDT
  RURAL NORTHWESTERN CARTER COUNTY AT 220 PM MDT
  RURAL SOUTHWESTERN FALLON COUNTY AT 240 PM MDT
  RURAL NORTHERN CARTER COUNTY AT 300 PM MDT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR
DAMAGING WINDS...LARGE HAIL...AND DEADLY CLOUD TO GROUND LIGHTNING.
PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY INSIDE A STRONG
BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 4578 10478 4580 10558 4598 10528 4623 10539
      4630 10458 4598 10450
TIME...MOT...LOC 1957Z 270DEG 19KT 4615 10520 4598 10513
          4585 10534

$$
2 follow-up statements
226 
WWUS55 KBYZ 022034
SVSBYZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BILLINGS MT
234 PM MDT THU AUG 2 2012

MTC011-017-025-022100-
/O.CON.KBYZ.SV.W.0021.000000T0000Z-120802T2100Z/
CARTER MT-CUSTER MT-FALLON MT-
234 PM MDT THU AUG 2 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM MDT
FOR WEST CENTRAL FALLON...SOUTHEASTERN CUSTER AND NORTHWESTERN CARTER
COUNTIES...

AT 232 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM WITH GOLF BALL SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED OVER
SOUTHEASTERN CUSTER COUNTY...OR 26 MILES WEST OF EKALAKA...MOVING
EAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  RURAL NORTHWESTERN CARTER COUNTY AT 250 PM MDT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT
THURSDAY EVENING FOR SOUTHEAST MONTANA.

&&

LAT...LON 4594 10455 4588 10463 4580 10515 4597 10524
      4627 10494 4629 10476
TIME...MOT...LOC 2034Z 250DEG 31KT 4592 10506

$$
090 
WWUS55 KBYZ 022058
SVSBYZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BILLINGS MT
258 PM MDT THU AUG 2 2012

MTC011-017-025-022108-
/O.CAN.KBYZ.SV.W.0021.000000T0000Z-120802T2100Z/
CARTER MT-CUSTER MT-FALLON MT-
258 PM MDT THU AUG 2 2012

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL FALLON...
SOUTHEASTERN CUSTER AND NORTHWESTERN CARTER COUNTIES IS CANCELLED...

THE STORMS HAVE WEAKENED ARE NO LONGER CONSIDERED SEVERE. HEAVY 
RAIN...SMALL HAIL AND DANGEROUS LIGHTNING ARE STILL EXPECTED WITH 
THUNDERSTORMS THIS AFTERNOON. 

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT
THURSDAY EVENING FOR SOUTHEAST MONTANA.

LAT...LON 4594 10455 4588 10463 4580 10515 4597 10524
      4627 10494 4629 10476
TIME...MOT...LOC 2058Z 270DEG 19KT 4614 10473 4597 10467
          4584 10488

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 1:33 PM MDTSpecial Weather StatementBYZPowder River57 min
Aug 2, 1:46 PM MDTSevere Thunderstorm WarningBYZPowder River59 min
Aug 2, 2:19 PM MDTSevere Thunderstorm WarningBYZCarter, Powder River56 min
Aug 2, 2:52 PM MDTSpecial Weather StatementBYZFallon53 min
Aug 2, 3:15 PM MDTSevere Thunderstorm WarningBYZCarter, Powder River26 min
Aug 2, 3:55 PM MDTSpecial Weather StatementBYZCarter65 min
Aug 2, 4:41 PM MDTSpecial Weather StatementBYZCarter34 min

Nearby

Severe Thunderstorm Warnings in Montana, 2012Every severe thunderstorm warning in 2012

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.