A cold front and an area of low surface pressure combined with a moist and unstable environment to sustain multiple severe thunderstorms across portions of northeast Montana during the afternoon hours.
Every event with a place to put it. Tap one for its entry below.
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 GGW wrote it up.
A cold front and an area of low surface pressure combined with a moist and unstable environment to sustain multiple severe thunderstorms across portions of northeast Montana during the afternoon hours.
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 Glasgow, MT wrote its last area forecast discussion before the first event at Jul 4, 8:34 AM MST, 3 hours 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 934 AM MDT SAT JUL 4 2015 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY... UPDATE...GOING FORECAST IS IN GOOD SHAPE. ONLY TWEAK WAS TO TREND THE WIND FORECAST TOWARD THE LATEST HIGH RESOLUTION MODELS TO REFLECT MORE SMALL SCALE DETAILS. REMAINDER OF FORECAST UNCHANGED WITH BREEZY CONDITIONS AND THUNDERSTORMS EXPECTED THIS AFTERNOON WITH A COLD FRONTAL PASSAGE. GILCHRIST PREVIOUS DISCUSSION...SHORTWAVE SWINGING THROUGH THE CANADIAN PRAIRIES WILL PUSH A COLD FRONT INTO NORTHEAST MONTANA THIS AFTERNOON. COMPRESSIONAL WARMING AHEAD OF THE FRONT WILL AGAIN PUSH TEMPERATURES INTO THE 90S TODAY. AIRMASS DESTABILIZED WITH THE SURFACE HEATING...AND THUNDERSTORM POSSIBLE...MAINLY WITH THE CONVERGENCE PROVIDED BY THE FRONT. WITH INVERTED V SOUNDING AHEAD OF THE FRONT...GUSTY WINDS WITH LITTLE RAINFALL ARE EXPECTED TO BE THE MAIN THREAT WITH EARLY THUNDERSTORMS. AS THE AIRMASS COOLS BEHIND THE FRONT...AND PW AROUND AN INCH FOR MOST OF THE REGION...STORMS SHOULD BEGIN TO PRODUCE MORE RAIN DURING THE OVERNIGHT HOURS. WHILE WINDS ARE EXPECTED TO INCREASE AS THEY TURN NORTHWEST BEHIND THE FRONT...MAIN CONCERN FOR BOATING INTERESTS ON FORT PECK LAKE WILL BE POTENTIAL FOR ERRATIC GUSTS FROM THUNDERSTORM OUTFLOW. ANOTHER SHORTWAVE PUSHES ACROSS MONTANA ON SUNDAY...FOR A BETTER CHANCE OF RAIN FOR MOST OF THE REGION. CLEARING EXPECTED TO WORK INTO THE REGION FROM THE NORTHWEST BY SUNDAY EVENING AS HIGH PRESSURE SPREADS INTO THE STATE. DRIER BUT STILL COOL WEATHER EXPECTED ON MONDAY WITH THE HIGH PRESSURE OVER EASTERN MONTANA AND NORTHWEST FLOW ALOFT FOLLOWING THE UPPER WAVE. EBERT .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... THE EXTENDED PERIOD KICKS OFF ON MONDAY NIGHT WITH NORTHWEST FLOW ALOFT OVER THE NORTHERN HIGH PLAINS WITH AN UPSTREAM RIDGE ACROSS BRITISH COLOMBIA. DO EXPECT A COLD FRONTAL PASSAGE SOMETIME TUESDAY WHICH COULD RESULT IN AN ISOLATED SHOWER OR THUNDERSTORM. WEDNESDAY INTO FRIDAY...UPPER RIDGE WILL AMPLIFY OVER THE HIGH PLAINS ALLOWING FOR DRY WEATHER CONDITIONS AND WARMING TEMPERATURES. WILL HAVE HIGHS ONCE AGAIN APPROACHING 90 DEGREES BY WEDNESDAY OR THURSDAY. TOWARD THE WEEKEND...MODEL SOLUTIONS POINT TOWARD A PACIFIC TROUGH DEVELOPING...ALLOWING FOR SOUTHWEST FLOW ALOFT TO BECOME ESTABLISHED ACROSS THE REGION AS THE RIDGE AXIS SLIDES EAST. TIMING OF THESE DEVELOPMENTS REMAIN SOMEWHAT UNCERTAIN AND ENSEMBLE SPREAD IN THE 500MB HEIGHTS INCREASES CONSIDERABLY TOWARD THE END OF THE PERIOD...HOWEVER...BROAD AGREEMENT ON UNSETTLED WEATHER CONDITIONS RETURNING TO NORTHEAST MONTANA EXISTS AND SO INTRODUCED SLIGHT CHANCE TO LOW END CHANCE POPS TO FINISH OUT THE PERIOD. WITH UPPER LEVEL DIFFLUENT SOUTHWEST FLOW ALOFT...ANY SHORTWAVE APPROACHING THE AREA COULD EASILY ASSIST IN CONVECTION INITIATION AND SO WILL MENTION SHOWERS AND THUNDERSTORMS ON SATURDAY FOR NOW. MALIAWCO && .AVIATION... SMOKEY HAZE CONTINUES...WITH SOME MVFR AS A RESULT. VISUAL SATELLITE IMAGERY OF SOUTHERN ALBERTA SHOWS MORE SMOKE BEHIND THE COLD FRONT COMING IN FROM THE NORTHWEST. SATELLITE IMAGERY AND THE LIGHTNING DETECTION NETWORK ARE ALSO SHOWING SCATTERED THUNDERSTORMS MOVING EAST ACROSS SOUTHERN SASKATCHEWAN THIS MORNING. AS THE COLD FRONT PASSES THROUGH THE LOCAL AREA...EXPECT ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. SOME STRONGER STORMS MAY ALSO PRODUCE TEMPORARY MVFR VISIBILITY. EXPECT SOUTHEAST WINDS AT 5-10 KTS THIS MORNING TO INCREASE AND TURN VEER NORTH TO NORTHEASTERLY BY THIS EVENING AT 10 TO 20 KTS BEHIND THE COLD FRONTAL PASSAGE. SPC HAS PLACED ALL OF NORTHEAST MONTANA IN A MARGINAL RISK FOR SEVERE WEATHER AREA FOR TODAY AND EVENING. SO THERE IS THE SMALL POSSIBILITY OF SUPER-CELL DEVELOPMENT RESULTING IN LARGE HAIL AND DAMAGING WINDS. SINCE IT IS TOO ISOLATED TO PREDICT...EXPECT TAF AMENDS IF AND WHEN STORMS DEVELOP THAT WOULD AFFECT THE TERMINALS. SCT && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 338 AM MDT SAT JUL 4 2015 MTZ016>027-059>062-051000- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE- RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS- SOUTHWEST PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT- 338 AM MDT SAT JUL 4 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT HOT AND DRY CONDITIONS ARE EXPECTED TODAY WITH THE APPROACH OF A COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONTAL PASSAGE DURING THE AFTERNOON AND EVENING...WITH GUSTY WINDS AND SMALL HAIL POSSIBLE WITH THE STRONGER STORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GLASGOW MT 1241 PM MDT SAT JUL 4 2015 MTZ023>025-041945- DAWSON-MCCONE-RICHLAND- 1241 PM MDT SAT JUL 4 2015 THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... WESTERN RICHLAND COUNTY IN NORTHEAST MONTANA... EASTERN MCCONE COUNTY IN NORTHEAST MONTANA... NORTHWESTERN DAWSON COUNTY IN NORTHEAST MONTANA... UNTIL 145 PM MDT. AT 1240 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 11 MILES SOUTHWEST OF VIDA...MOVING EAST AT 30 MPH. HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM. LOCATIONS IN THE ADVISORY INCLUDE... VIDA... RICHEY... THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. LAT...LON 4793 10483 4732 10495 4765 10582 4785 10575 TIME...MOT...LOC 1841Z 280DEG 24KT 4772 10567 TEMPLER WEATHER.GOV/GLASGOW
The Glasgow radar (KGGW), 100 km away, was scanning. The volume nearest the first event began at 19:03 UTC.
6 hail, 2 thunderstorm wind. Local standard time, as filed.
Public reported hail up to the size of quarters covering the ground, brief heavy rain, and wind gusts up to 50 mph.
Public reported nickel-sized hail near the southern edge of the thunderstorm.
Public reported hail up to the size of golf balls.
Report relayed through the Dawson County dispatch office. Estimated wind gusts of 70 to 80 mph along highway 256 at mile marker 24.
Trained spotter reported 58 mph winds and pea-sized hail.
Public reported quarter-sized hail.
Public reported half dollar sized hail.
Public reported quarter-sized hail.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2015Every state in 2015This day in weather historyWarnings in Montana, July 2015
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: 593447, 593448, 593449, 593459, 593460, 593456, 593457, 593458.