Alert archive / Montana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 4, NWS Missoula, MT

July 2, 1990Broadwater County, Lewis and Clark County, Meagher County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 2, 1990, 4:39 PM MDT for Broadwater County, Lewis and Clark County, Meagher County, Montana. It was in force for 66 min.

The area

The counties it named.

The facts

Issued
Jul 2, 1990, 4:39 PM MDT (22:39 UTC)
Expired
Jul 2, 1990, 5:45 PM MDT
In force
66 min
Issued by
NWS Missoula, MT
Area
Whole counties

Counties Broadwater County, MT, Lewis and Clark County, MT, Meagher County, MT

The radar

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

The nearest sounding before it

Great Falls, MT (KGTF), launched 12:00Z, 10.7 hours before the alert went out and 91 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 KHLN 022239
SVRHLN
MTC007-049-059-022345-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HELENA MT
439 PM MDT MON JUL 2 1990
 
THE NATIONAL WEATHER SERVICE IN HELENA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  545 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHWEST MONTANA
 
   ...NORTHERN BROADWATER COUNTY...LEWIS AND CLARK COUNTY
   ...NORTHERN MEAGHER COUNTY
 
SEVERE THUNDERSTORMS CONTINUE TO MOVE INTO THE SOUTHWESTERN MONTANA
AREA THEY ARE MOVING TOWARDS THE NORTHEAST AT 45 MPH. THESE STORMS
COULD QUITE POSSIBLY CAUSE WINDS IN EXCESS OF 55 MPH AND LARGE HAIL.
 
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.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 2, 3:49 PM MDTSevere Thunderstorm WarningMSOBroadwater, Lewis and Clark56 min
Jul 2, 4:01 PM MDTSevere Thunderstorm WarningMSOMeagher59 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; the sounding from the Mesonet's radiosonde archive.