Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 76, NWS Great Falls, MT

August 7, 1998Pondera County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 7, 1998, 4:19 PM MDT for Pondera County, Montana. It was in force for 51 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
Aug 7, 1998, 4:19 PM MDT (22:19 UTC)
Expired
Aug 7, 1998, 5:10 PM MDT
In force
51 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Pondera County, MT

The radar

The Great Falls radar (KTFX), 106 km from the middle of the area, began a volume at 22:20 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 nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.3 hours before the alert went out and 148 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 1998-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 70 joules per kilogram.LCLLFCEL10008507005003002001001 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 1998-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 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
70 J/kg
Mixed-layer CIN
-254 J/kg
Mixed-layer LCL
1445 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
153 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.

496 
WUUS1 KGTF 072223 RRA
SVRGTF
MTC073-072310-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
419 PM MDT FRI AUG 7 1998


THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL AND EASTERN PONDERA COUNTY IN NORTHWESTERN MONTANA

* UNTIL 510 PM MDT

* AT 418 PM MDT... DOPPLER RADAR AT GREAT FALLS INDICATED A SEVERE
  THUNDERSTORM 18 MILES WEST OF CONRAD OR 8 MILES SOUTHWEST OF
  VALIER MOVING NORTHEAST AT 30 MPH.

* SOME LOCATIONS IN OR NEAR THE PATH OF THIS STORM ARE...   VALIER
  AND   LEDGER.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 3:54 PM MDTSevere Thunderstorm WarningTFXBroadwater, Jefferson, Lewis and Clark46 min
Aug 7, 4:10 PM MDTSevere Thunderstorm WarningTFXCascade, Teton35 min
Aug 7, 4:45 PM MDTSevere Thunderstorm WarningTFXCascade, Chouteau, Teton45 min
Aug 7, 4:51 PM MDTSevere Thunderstorm WarningTFXLewis and Clark49 min
Aug 7, 4:57 PM MDTSevere Thunderstorm WarningTFXPondera, Toole48 min
Aug 7, 5:19 PM MDTSevere Thunderstorm WarningTFXLiberty, Toole36 min
Aug 7, 5:25 PM MDTSevere Thunderstorm WarningTFXChouteau50 min
Aug 7, 5:39 PM MDTSevere Thunderstorm WarningTFXBroadwater, Meagher51 min
Aug 7, 5:39 PM MDTSevere Thunderstorm WarningTFXJefferson51 min
Aug 7, 5:48 PM MDTSevere Thunderstorm WarningTFXLiberty42 min

Nearby

Severe Thunderstorm Warnings in Montana, 1998Every severe thunderstorm warning in 1998

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.