Strong gusty winds throughout Granite and Deer Lodge Counties caused widespread power outages. In Philipsburg a 8 by 11 foot metal storage shed was lifted into the air and ended up onto power lines, triggering an outage that stretched from Anaconda Job Corps through Georgetown Lake, Philipsburg and Drummond.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MSO wrote it up.
Strong gusty winds throughout Granite and Deer Lodge Counties caused widespread power outages. In Philipsburg a 8 by 11 foot metal storage shed was lifted into the air and ended up onto power lines, triggering an outage that stretched from Anaconda Job Corps through Georgetown Lake, Philipsburg and Drummond. A transmission pole was also blown down onto power lines in Drummond causing power outages.
The local office's own words before the first event, 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 the first event at Apr 15, 10:22 AM MST, 2 hours 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MISSOULA MT 1122 AM MDT THU APR 15 2004 .UPDATE...UPDATED TO ADD WINDS TO IDAHO CAMAS PRAIRIE AND HELLS CANYON. WINDS HAVE PICKED UP HIGHER THAN EXPECTED NEAR GRANGEVILLE...THOUGH SHOULD TAPER OFF LATE AFTERNOON AFTER FRONT MOVES EAST AND SURFACE GRADIENT RELAXES. && .PREVIOUS FORECAST...TODAY THROUGH SATURDAY. A LARGE UPPER LOW PRESSURE SYSTEM ENCOMPASSES THE ENTIRE PAC NORTHWEST WITH A RATHER VIGOROUS CIRCULATION OVER SOUTHWEST OR EARLY THIS MORNING. THIS SYSTEM IS ASSOCIATED WITH A JET STREAK ENTERING SOUTHEAST ID. THUNDERSTORMS HAVE CONTINUED EAST OF THE CASCADES OVERNIGHT ALONG THE COLD FRONT WHICH IS AN INDICATION OF STRONG FORCING ABOVE THE STABLE LOW LEVELS. WILL LEAN TOWARD THE GFS MODEL GIVEN THE RECENT TRACK RECORD AND INITIALIZATION. THE FRONT SWEEPS ACROSS SOUTHERN ID INTO SOUTHWEST MT DURING THE MORNING WITH STRONGEST LIFT IN THIS REGION. MOISTURE PROFILES SHOW DRIER AIR BELOW CLOUD BASES IN THE SOUTHERN AREAS FOR POTENTIAL GUSTY WINDS NEAR SHOWERS AND THUNDERSTORMS ALONG THE FRONT. FARTHER NORTH A LARGE DEFORMATION ZONE WILL DEVELOP WITH WIDESPREAD SHOWERS. HAVE INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS FOR COORDINATION PURPOSES IN THIS AREA...BUT BELIEVE LIGHTNING WITH BE HARDER TO ACHIEVE DUE TO LESS HEATING POTENTIAL. COLD POOL ALOFT WILL HELP DESTABILIZE THE AIR MASS THOUGH AND LOW FREEZING LEVELS COULD RESULT IN SMALL HAIL. PRESSURE GRADIENT BEHIND THE COLD FRONT WILL GENERATE 10-20 MPH WINDS ACROSS MANY AREAS TODAY. ETA MODEL DEVELOPS MORE RIDGING ALOFT COMPARED TO THE GFS ON FRIDAY. WILL CONTINUE WITH THE WETTER GFS SHOWING AN INVERTED SURFACE TROUGH AND SOUTHWEST FLOW ALOFT OVER THE NORTHERN ROCKIES. LITTLE CHANGE OCCURS IN THIS SCENARIO THROUGH SATURDAY AS THE PARENT UPPER LOW ROTATES INLAND TOWARD THE GREAT BASIN. TEMPERATURES WILL BE COOLER THAN NORMAL IN THIS PATTERN. ...SATURDAY NIGHT THROUGH WEDNESDAY...MODELS HAVE COME SOMEWHAT IN LINE THIS SET OF RUNS. HOWEVER CONFIDENCE IS STILL LACKING DUE TO PAST PERFORMANCE. HAVE MADE ONLY MINOR TWEAKS TO EXISTING FORECAST. UPPER LEVEL TROUGH SHIFTS EASTWARD THROUGH TUESDAY EVENING KEEPING A MENTION OF PRECIPITATION IN THE FORECAST. WEDNESDAY BEGINS A DRYING TREND AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE REBOUNDS INTO THE NORTHERN ROCKIES. TEMPERATURES WILL HANG RIGHT AROUND SEASONABLE THROUGH THE PERIOD WITH A SLIGHT WARMING TREND. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...NONE. ID...NONE. && UPDATE/MWJ PREVIOUS DISCUSSION/BOLDT/GILCHRIST
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2004Every state in 2004This day in weather historyWarnings in Montana, April 2004
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5391137.