Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 19, NWS Missoula, MT

July 19, 1997Powell County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 19, 1997, 12:00 PM MDT for Powell County, Montana. It was in force for 45 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: Jul 19, 1997, 12:00 PM MDT (18:00 UTC)
Expired: Jul 19, 1997, 12:45 PM MDT
In force: 45 min
Issued by: NWS Missoula, MT
Area: Whole counties

County Powell County, MT

The radar

The Missoula radar (KMSX), 82 km from the middle of the area, began a volume at 18:04 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, 6.0 hours before the alert went out and 189 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 122 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 1225 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 51 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 191806 RRA
SVRMSO
MTC077-191845-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
NOON MDT SAT JUL 19 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1245 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN WEST CENTRAL MONTANA
 
   ...SOUTHERN POWELL COUNTY
 
AT NOON MDT RADAR INDICATED A SEVERE THUNDERSTORM IN SOUTHERN POWELL
COUNTY 15 MILES NORTH OF GARRISON. THE STORM WAS MOVING NORTH AT 20 MPH.
IT WILL CONTINUE MOVING OVER THE GARNET MOUNTAIN RANGE...AND CROSS STATE
HIGHWAY 141 BY 1215 PM MDT. IT WILL THEN CROSS INTO LEWIS AND CLARK
COUNTY BY 1230 PM MDT.
 
SEVERE THUNDERSTORMS PRODUCE 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 DON'T DRIVE INTO AREAS WHERE
WATER COVERS THE ROAD.
 
WHITMORE

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 Jul 19, 9:15 AM MDT, 2 hours 45 minutes earlier.

Area forecast discussion, Jul 19, 9:15 AM MDT, 2 hours 45 minutes before

WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
915 AM MDT SAT JUL 19 1997

THUNDERSTORM ACTIVITY CONTINUING...MAINLY OVER SOUTHWEST
MONTANA...BUT PLENTY OF SHOWERS ELSEWHERE AS VORT LOBES PINWHEEL
AROUND LOW.  NO NEW MODELS TO LOOK AT...HOWEVER STILL HAVE SOME
CHANGES IN MIND.  RADAR AND SATELLITE SHOWING BAND OF MOISTURE MAKING
IT UP INTO NORTHWEST MONTANA.  BELIEVE LATER BANDS SHOULD ALSO
PROGRESS INTO THE NORTH.  SO WILL BUMP UP POPS FIRST PERIOD.
MOISTURE ALSO TRACKING INTO NORTH CENTRAL IDAHO.  LATER BANDS MAY
HAVE MORE DIFFICULTY MOVING THAT FAR WESTWARD AS THE UPPER LOW DRIFTS
EAST...BUT POPS COULD STILL BE RAISED.  TEMPS LOOK REASONABLE.  WORK
ZONES DO CONTAIN CHANGES.             WHITMORE

...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 082/057 084/... ... 34532
FCA WE 081/056 080/054 082 34643
POL .. 081/057 085/... ... 34753
MSO WE 078/056 082/055 085 34874
HMM .. 077/055 085/... ... 34864
BTM .. 070/050 073/... ... 34975
S80 .. 075/055 084/... ... 34632
P69 .. 078/058 081/... ... 34742
SMN .. 073/053 082/... ... 34642

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 8:30 AM MDT	Severe Thunderstorm Warning	MSO	Beaverhead, Silver Bow	60 min
Jul 19, 9:34 AM MDT	Severe Thunderstorm Warning	MSO	Deer Lodge	56 min
Jul 19, 2:19 PM MDT	Flash Flood Warning	MSO	Beaverhead	56 min
Jul 19, 2:19 PM MDT	Severe Thunderstorm Warning	MSO	Beaverhead	56 min
Jul 19, 3:06 PM MDT	Tornado Warning	MSO	Beaverhead	69 min
Jul 19, 4:00 PM MDT	Severe Thunderstorm Warning	MSO	Silver Bow	60 min
Jul 19, 5:25 PM MDT	Severe Thunderstorm Warning	MSO	Powell	50 min

Nearby

Severe Thunderstorm Warnings in Montana, 1997 Every severe thunderstorm warning in 1997

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.