Alert archive / Montana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 3, NWS Great Falls, MT

July 2, 1990Cascade County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 2, 1990, 4:06 PM MDT for Cascade County, Montana. It was in force for 69 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 2, 1990, 4:06 PM MDT (22:06 UTC)
Expired
Jul 2, 1990, 5:15 PM MDT
In force
69 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Cascade County, MT

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
Jul 2, 4:30 PM MDTThunderstorm Wind 75Cascade, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Great Falls, MT (KGTF), launched 12:00Z, 10.1 hours before the alert went out and 19 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 1990-07-02Temperature 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°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 1990-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 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
2690 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
72 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 
TTAA00 KGTF 022205
SVRGTF
MTC013-022315-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
406 PM MDT MON JUL 2 1990
 
THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  515 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION......
 
IN NORTH CENTRAL MONTANA
 
   ...CASCADE COUNTY...INCLUDING THE CITY OF GREAT FALLS.
 
RADAR INDICATES A LIKELY SEVERE THUNDERSTORM JUST ENTERING SOUTHWEST
CASCADE COUNTY. THIS STORM IS MOVING NORTHEAST AT 45 MPH AND SHOULD
HIT THE CITY OF GREAT FALLS IN 30 MIN.
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

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.

In the hours before

Special weather statement, Jul 2, 3:28 PM MDT, 38 minutes before
MTZ006-022300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
330 PM MDT MON JUL 2 1990

STRONG THUNDERSTORMS ARE MOVING EASTWARD ACROSS WESTERN JUDITH BASIN
COUNTY AT 330 PM MDT

THGESE THUNDERSTORMS WILL MOST LIKELY CONTAIN GUSTY WINDS...SMALL
HAIL AND BRIEF HEAVY RAINFALL.  THESE THUNDERSTORMS WILL MOVE ACROSS
STANFORD DURING THE NEXT HALF HOUR.
SIMS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 2, 4:23 PM MDTSevere Thunderstorm WarningTFXTeton67 min

Nearby

Severe Thunderstorm Warnings in Montana, 1990Every severe thunderstorm warning in 1990

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.