Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 14, NWS Missoula, MT

July 12, 2001Powell County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 12, 2001, 6:16 PM MDT for Powell County, Montana. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued
Jul 12, 2001, 6:16 PM MDT (00:16 UTC)
Expired
Jul 12, 2001, 7:00 PM MDT
In force
44 min
Issued by
NWS Missoula, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Powell County, MT

What was reported inside it

TimeReportWhereRemark
Jul 12, 6:17 PM MDTHail 0.75Deer Lodge, 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.

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 0.3 hours before the alert went out and 194 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 00:00Z on 2001-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 255 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, Great_falls, MT at 00:00Z on 2001-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
255 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1606 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
101 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KMSO 130018
SVRMSO

MTC077-130100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
616 PM MDT THU JUL 12 2001

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN POWELL COUNTY IN WEST CENTRAL MONTANA

* UNTIL 700 PM MDT

* AT 616 PM MDT...SPOTTERS REPORTED A SEVERE THUNDERSTORM 5 MILES    
  SOUTH OF DEER LODGE...MOVING NORTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN SOUTH OF DEER LODGE AND MOVE
  OVER REMOTE AREAS.

LARGE HAIL IS LIKELY WITH THIS SEVERE THUNDERSTORM...IN ADDITION TO
HEAVY RAIN. FOR YOUR PROTECTION...GO INDOORS AND STAY AWAY FROM 
WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL PROTECTED AREA.


LAT...LON 4637 11289 4622 11276 4643 11220 4661 11241

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 12, 2:30 PM MDT, 3 hours 46 minutes earlier.

Area forecast discussion, Jul 12, 2:30 PM MDT, 3 hours 46 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
230 PM MDT THU JUL 12 2001

.SHORT TERM...SHOWERS AND THUNDERSTORMS FIRING OFF EARLY THIS
AFTERNOON ACROSS THE SOUTHERN ZONES IN RESPONSE TO A VORT MAX
LOCATED SOUTH OF MISSOULA. NEGATIVE LI'S AND STEEPEST LAPSE RATES
OVER THE SOUTHEASTERN ZONES THIS EVENING. SOUTHWEST FLOW ALOFT
CONTINUES ACROSS THE CWA THROUGH THE FORECAST PERIOD. SERIES OF WEAK
SHORT WAVES MOVE IN THE FLOW AND ACROSS THE AREA EACH DAY. 12Z AVN
AND ETA SIMILAR BUT FEEL THE AVN INITIALIZED BETTER. MAIN DIFFERENCE
IS ON SATURDAY...THE AVN IS DRIER ACROSS THE CWA. WILL TREND THE POPS
DOWN ON SATURDAY...BUT STILL KEEP WORDING FOR A SLIGHT CHANCE OF
SHOWERS IN. KOLATA

.EXTENDED...MODELS SIMILAR IN BRINGING THE OFFSHORE TROUGH INLAND
SUNDAY OVER WASHINGTON AND OREGON AND THEN STALLING IT. THE
ASSOCIATED CLOSED LOW ALONG THE WA/CANADIAN BORDER WEAKENS AND EJECTS
TO THE NORTHEAST INTO CANADA BY WEDNESDAY MORNING. THE MRF
MAKES THE FLOW ALOFT SLIGHTLY MORE WESTERLY...WHILE THE ECMWF KEEPS
THE FLOW SOUTHWEST BY WEDNESDAY. COOLER TEMPS EXPECTED EITHER
WAY FOR SUNDAY THROUGH TUESDAY...THEN A WARMING TREND AGAIN WITH
HEIGHTS ALOFT RISING SLOWLY WITH SOUTHWEST FLOW PERSISTING. NO
CHANGE AS FAR AS THE AFTERNOON AND EVENING CONVECTION IS CONCERNED
WITH A CHANCE EACH DAY...MAINLY SOUTHERN ZONES. FELSCH

.MSO...NONE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 2:32 PM MDTSevere Thunderstorm WarningMSORavalli33 min
Jul 13, 5:43 PM MDTSevere Thunderstorm WarningMSOSilver Bow37 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001Every severe thunderstorm warning in 2001

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.