Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 82, NWS Great Falls, MT

August 4, 2001Jefferson County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 4, 2001, 2:18 PM MDT for Jefferson County, Montana. It was in force for 27 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: Aug 4, 2001, 2:18 PM MDT (20:18 UTC)
Expired: Aug 4, 2001, 2:45 PM MDT
In force: 27 min
Issued by: NWS Great Falls, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Jefferson County, MT

The radar

The Great Falls radar (KTFX), 133 km from the middle of the area, began a volume at 20:21 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.

Issued	Product	Office	Lasted
Aug 4, 2:00 PM MDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.3 hours before the alert went out and 167 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: 38 J/kg
Mixed-layer CIN: -272 J/kg
Mixed-layer LCL: 2483 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: -70 m²/s²
0-3 km storm-relative helicity: -33 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.

009 
WUUS55 KTFX 042018
SVRGTF
MTC043-042045-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
218 PM MDT SAT AUG 4 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL JEFFERSON COUNTY IN SOUTHWEST MONTANA

* UNTIL 245 PM MDT

* AT 200 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 12 MILES WEST OF WICKES...OR ABOUT 13 MILES
  NORTHWEST OF BOULDER...MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES NORTHWEST OF CORBIN AT 230 PM MDT
  5 MILES NORTHWEST OF CLANCY AT 245 PM MDT

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN GREAT FALLS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM MDT
SATURDAY EVENING FOR WESTERN MONTANA.

LAT...LON 4635 11233 4619 11220 4651 11185 4653 11200

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 Aug 4, 8:53 AM MDT, 5 hours 25 minutes earlier.

Area forecast discussion, Aug 4, 8:53 AM MDT, 5 hours 25 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
853 AM MDT SAT AUG 4 2001

WILL UPDATE ZONES THIS MORNING TO INCREASE MAX TEMPERATURES F0R THIS
AFTERNOON AND REFLECT THE MOSTLY CLEAR CONDITIONS THIS MORNING.
FIRST SHORT WAVE WENT CWA THROUGH LAST NIGHT...THE 2ND NOW MOVING
THROUGH EASTERN WASHINGTON.  WATER VAPOR IMAGERY SHOWS DRY SLOT
THROUGH WRN 3RD MONTANA...RESULTING IN MOSTLY CLEAR SKIES...ALLOWING
GOOD INSOLATION AHEAD OF NEXT TROUGH.  SFC ANALYSIS SUGGESTS COLD
FRONT NEAR CTB THEN EXTENDING SW ACROSS THE DIVIDE. DON NOT EXPECT
THIS FRONT TO ACTIVELY ADVANCE UNTIL MUCH LATER TODAY. NEW ETA
PREDICTS THAT THE STRONGEST DYNAMICS WILL AFFECT THE CWA LATE THIS
AFTERNOON AND EVENING. GREATEST THREAT WILL BE THE WINDS WITH HIGH
BASED TSTMS.  WE HAVE ISSUED RED FLAG WARNING FOR LOW RH, DRY TSTMS
AND ASSOCIATED WINDS. MIELKE

GTF EU 095/057 087/055 092 14330
CTB EU 085/052 084/050 088 14330
HLN EU 095/052 089/050 091 14330
BZN EU 094/052 090/050 092 14330
WEY EU 087/044 084/042 088 14330
DLN EU 088/048 086/046 088 14320
HVR EU 099/060 090/058 094 14230
LWT EU 097/055 088/053 090 14230

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 1:17 PM MDT	Severe Thunderstorm Warning	TFX	Beaverhead	28 min
Aug 4, 1:28 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Lewis and Clark	47 min
Aug 4, 2:15 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	60 min
Aug 4, 3:12 PM MDT	Severe Thunderstorm Warning	TFX	Lewis and Clark	63 min
Aug 4, 3:39 PM MDT	Severe Thunderstorm Warning	TFX	Judith Basin	66 min
Aug 4, 3:49 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	26 min
Aug 4, 3:59 PM MDT	Severe Thunderstorm Warning	TFX	Broadwater	31 min
Aug 4, 4:00 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	30 min
Aug 4, 4:09 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	51 min
Aug 4, 4:43 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	32 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001 Every 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; radar from the NEXRAD Level II archive.