Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 39, NWS Billings, MT

June 21, 2002Big Horn County, Rosebud County, Montana

NWS Billings, MT issued this severe thunderstorm warning at Jun 21, 2002, 2:35 PM MDT for Big Horn County, Rosebud County, Montana. It was in force for 55 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jun 21, 2002, 2:35 PM MDT (20:35 UTC)
Expired: Jun 21, 2002, 3:30 PM MDT
In force: 55 min
Issued by: NWS Billings, MT
Area: Counties, with a storm outline in the text

Counties Big Horn County, MT, Rosebud County, MT

The radar

The Billings radar (KBLX), 139 km from the middle of the area, began a volume at 20:35 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.

What was reported inside it

Time	Report	Where	Remark
Jun 21, 3:35 PM MDT	Hail 0.75	Colstrip, MT

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 8.6 hours before the alert went out and 295 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: 2135 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 95 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 KBYZ 212035
SVRBYZ
MTC003-087-212130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BILLINGS MT
235 PM MDT FRI JUN 21 2002

THE NATIONAL WEATHER SERVICE IN BILLINGS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL BIG HORN COUNTY IN SOUTH CENTRAL MONTANA
  SOUTH CENTRAL ROSEBUD COUNTY IN SOUTHEAST MONTANA

* UNTIL 330 PM MDT

* AT 235 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER BUSBY...OR ABOUT 30 MILES SOUTHWEST OF
  COLSTRIP...MOVING NORTH AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
   LAME DEER BY 255 PM MDT.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

LAT...LON 4538 10715 4535 10650 4587 10643 4588 10709

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 Billings, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 2:09 PM MDT, 26 minutes earlier.

Area forecast discussion, Jun 21, 2:09 PM MDT, 26 minutes before

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
209 PM MDT FRI JUN 21 2002

.SHORT TERM...VALID FOR SAT...SUN...MON...
UPPER LOW DIGGING INTO CENTRAL CALIFORNIA THIS AFTERNOON SPITTING OUT A
COUPLE OF DISTURBANCES ACROSS OUR AREA WHICH SHOULD LEAD TO SIGNIFICANT
CONVECTION THIS EVENING...ALREADY DEVELOPING OVER SHERIDAN COUNTY ATTM.
AS MENTIONED IN PREVIOUS DISCUSSIONS ATMOSPHERE SET UP FOR SEVERE
THUNDERSTORMS ESPECIALLY FROM ROSEBUD COUNTY EAST WITH CAPES TO 3000
J/KG...LIS TO -10...AND WIND SHEAR TO 30 M/S. CONVECTION SHOULD LINGER
INTO THE MORNING IN THE EAST...WHILE TAPERING OFF AFTER MIDNIGHT WEST.
FOR SATURDAY UPPER TROF BECOMES NEGATIVELY TILTED AS IT MOVES INTO
WYOMING ALLOWING EASTERLY FLOW TO CONTINUE ACROSS THE AREA AND BRINGING
ANOTHER BATCH OF SHOWERS AND THUNDERSTORMS BY EARLY AFTERNOON. STRONG
CURVATURE OF SYSTEM WILL SLOW MOVEMENT DOWN KEEPING SHOWERS GOING
SATURDAY NIGHT AND SUNDAY. SURFACE TO 700 MB LOW PRESSURE CENTERED OVER
EASTERN MONTANA WILL BRING NORTHEAST WINDS AND WRAP AROUND PRECIPITATION
TO MOST OF THE AREA OVERNIGHT SUNDAY...ENDING EARLY MONDAY MORNING IN
THE EAST AS SYSTEM FINALLY MOVES OUT. MODELS INDICATING SIGNIFICANT
PRECIPITATION TOTALS OVER THE NEXT FEW DAYS WITH MILES CITY PROGGED TO
GET THREE INCHES BY SUNDAY EVENING...THIS IS PROBABLY A BIT OVER DONE
DUE TO CONVECTIVE FEEDBACK BUT STILL EXPECT A GOOD SOAKING ACROSS THE
AREA. A WEAK DISTURBANCE MOVES ACROSS NORTHERN MONTANA MONDAY AFTERNOON
PRODUCING A SLIGHT CHANCE OF PRECIP IN THE FAR NORTHEAST ZONES BUT
PARTLY CLOUDY ELSEWHERE. CHAMBERS

.LONG TERM...VALID FOR TUE...WED...THU...FRI...
MODELS ALL CONSISTENT ON BRINGING DRY AND WARM WEATHER FOR THE EXTENDED
PERIOD. UPPER TROUGH SWINGS THROUGH MONDAY NIGHT AND SHOULD BE EAST OF
THE AREA TUESDAY. THE ONE THING TO WATCH IS THE AVN WAS BRINGING A WEAK
WAVE OVER THE BUILDING RIDGE AND PRODUCING MID LEVEL OMEGA OVER NORTHERN
WYOMING TUESDAY AND TUESDAY NIGHT. WILL LEAVE POPS OUT AS SUBSIDENCE
WITH BUILDING RIDGE SHOULD BE STRONG ENOUGH TO SQUELCH CONVECTION. LARGE
UPPER RIDGE THEN BUILDS IN AND HOLDS TIGHT THROUGH FRIDAY. HUMPHREY

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 061/081 061/078 055/084 059/088 062/091 064/091 064/091
    47/T    74/W    00/B    00/B    00/U    00/U    00/U
LVM 057/077 055/075 049/081 054/085 057/087 059/087 059/087
    46/T    42/W    00/U    00/B    00/U    00/U    00/U
HDN 063/083 063/079 055/085 058/089 060/092 062/092 062/092
    47/T    76/W    20/B    00/B    00/U    00/U    00/U
MLS 065/086 064/078 057/084 061/089 064/092 066/092 066/092
    64/T    77/W    42/T    20/B    00/U    00/U    00/U
4BQ 065/086 064/078 060/086 061/089 063/092 065/092 065/092
    66/T    77/W    40/E    00/B    00/U    00/U    00/U
BHK 064/085 062/077 057/085 059/087 062/090 064/090 064/090
    77/T    88/W    42/T    20/B    00/U    00/U    00/U
SHR 060/083 063/078 054/084 054/086 057/088 059/088 059/088
    68/T    86/W    00/B    00/B    00/U    00/U    00/U

.BYZ...
MT...NONE.
WY...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 21, 3:34 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Treasure	56 min
Jun 21, 3:54 PM MDT	Severe Thunderstorm Warning	BYZ	Rosebud	66 min
Jun 21, 5:00 PM MDT	Severe Thunderstorm Warning	BYZ	Rosebud	60 min

Nearby

Severe Thunderstorm Warnings in Montana, 2002 Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.