Alert archive / Idaho / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 1, NWS Missoula, MT

May 8, 1998Lemhi County, Idaho

NWS Missoula, MT issued this severe thunderstorm warning at May 8, 1998, 3:09 PM MDT for Lemhi County, Idaho. It was in force for 61 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
May 8, 1998, 3:09 PM MDT (21:09 UTC)
Expired
May 8, 1998, 4:10 PM MDT
In force
61 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Lemhi County, ID

The radar

The Pocatello radar (KSFX), 227 km from the middle of the area, began a volume at 21:12 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

Boise Airport, ID (KBOI), launched 12:00Z, 9.2 hours before the alert went out and 236 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, Boise Airport, ID at 12:00Z on 1998-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Boise Airport, ID at 12:00Z on 1998-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -91 square meters per square second.1939Sfc1 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
2 J/kg
Mixed-layer CIN
-234 J/kg
Mixed-layer LCL
1527 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-91 m²/s²
0-3 km storm-relative helicity
-28 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 KMSO 082110 RRA
SVRMSO
IDC059-082210-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
309 PM MDT (209 PM PDT) FRI MAY 8 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL LEMHI COUNTY IN EAST CENTRAL IDAHO

* UNTIL 410 PM MDT

* AT 300 PM MDT...SEVERE THUNDERSTORM INDICATED 15 MILES NORTHWEST
  OF SALMON...BY NATIONAL WEATHER SERVICE DOPPLER RADAR...MOVING
  SOUTHWEST AT 10 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  SALMON AT 330 PM MDT

SPOTTERS JUST NORTH OF SALMON REPORTED ONE INCH HAIL COVERING THE
GROUND AT 300 PM MDT WITH THIS STORM.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&*

END/BARKER

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 Missoula, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at May 8, 2:21 PM MDT, 48 minutes earlier.

Area forecast discussion, May 8, 2:21 PM MDT, 48 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
145 PM MDT FRI MAY 8 1998

UPPER TROUGH APPROACHING PACIFIC COAST WILL BECOME CLOSED BY 24 HOURS
AND SLOWLY MOVE ACROSS NORTHERN CALIFORNIA/NEVADA BY 60 HOURS.
SURFACE TROUGH NOW OVER WESTERN MONTANA WILL MOVE WEST OVER THE IDAHO
PANHANDLE UNDER BACKING FLOW. SATURDAY THE SURFACE THERMAL TROUGH
WILL EXTEND FROM THE NORTHERN IDAHO PANHANDLE DOWN INTO SOUTHWEST
MONTANA. ISOLATED THUNDERSHOWERS WILL AGAIN FORM ALONG THIS
BOUNDARY...HOWEVER BETTER MOISTURE WILL BE OVER SOUTHERN SECTIONS OF
IDAHO AND SOUTHEWEST MONTANA. WILL GO HIGHER POPS OVER SOUTHERN
SECTIONS OF OUR CWA SATURDAY AND CONTINUE THIS TREND INTO SUNDAY. BY
SUNDAY CLOSED LOW WILL MOVED INTO NORTHERN NEVADA WITH BEST
INSTABILITY OVER SOUTHERN IDAHO. A WEAK TROUGH WILL BE OVER NORTH
CENTRAL IDAHO AND WEST CENTRAL MONTANA WITH BEST MOISTURE AND
INSTABILITY SOUTH OF THE TROUGH NEAR THE COLDER AIR ALOFT.
TEMPERATURES WILL BE A FEW DEGREES COOLER SATURDAY AND SUNDAY DUE TO
A FEW MORE CLOUDS AND A SLIGHTLY COOLER AIR MASS.
TC
...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 043/078 042/076 ... 291111
FCA UB 041/077 040/075 042 291111
POL .. 049/076 049/074 ... 291112
MSO UB 044/079 043/077 044 292223
HMM .. 050/079 049/077 ... 292223
BTM .. 037/070 035/068 ... 292223
S80 .. 045/080 044/078 ... 291223
P69 .. 047/082 046/080 ... 291223
SMN .. 045/071 z043/070 ... 292224

Nearby

Severe Thunderstorm Warnings in Idaho, 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.