Alert archive / Montana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 19, NWS Missoula, MT

August 7, 1999Missoula County, Ravalli County, Montana; Idaho County, Idaho

NWS Missoula, MT issued this severe thunderstorm warning at Aug 7, 1999, 3:36 PM MDT for Missoula County, Ravalli County, Montana; Idaho County, Idaho. It was in force for 54 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, 1999, 3:36 PM MDT (21:36 UTC)
Expired
Aug 7, 1999, 4:30 PM MDT
In force
54 min
Issued by
NWS Missoula, MT
Area
Whole counties

Counties Idaho County, ID, Missoula County, MT, Ravalli County, MT

The radar

The Missoula radar (KMSX), 89 km from the middle of the area, began a volume at 21:37 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.

IssuedProductOfficeLasted
Aug 7, 3:15 PM MDTSevere Thunderstorm WatchSPC6 hr
Aug 7, 2:00 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 9.6 hours before the alert went out and 210 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, Spokane, WA at 12:00Z on 1999-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 207 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, Spokane, WA at 12:00Z on 1999-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
207 J/kg
Mixed-layer CIN
-109 J/kg
Mixed-layer LCL
1178 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 4:30 PM MDTSevere Thunderstorm WarningMSOLake, Missoula, Sanders60 min
Aug 7, 4:32 PM MDTSevere Thunderstorm WarningMSOClearwater58 min

Nearby

Severe Thunderstorm Warnings in Montana, 1999Severe Thunderstorm Warnings in Idaho, 1999Every severe thunderstorm warning in 1999

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.