A strong upper-level disturbance from the pacific northwest combined with an unstable low-level atmosphere to create many severe thunderstorms which progressed eastward across the area.
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 strong upper-level disturbance from the pacific northwest combined with an unstable low-level atmosphere to create many severe thunderstorms which progressed eastward across the area.
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 8, 1:34 PM MST, 1 minute earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 234 PM MDT MON JUL 8 2013 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... MAIN FOCUS FOR THE SHORT TERM PERIOD IS A STRONG UPPER LEVEL SHORTWAVE FEATURE PUSHING INTO WESTERN MONTANA THIS AFTERNOON. OUT AHEAD OF THIS WAVE THERE IS ENOUGH INSTABILITY TO GENERATE SOME SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS SHOW VERY GOOD CAPE/DIRECTIONAL WIND SHEAR PROFILES THROUGH TONIGHT AND PRECIPITABLE WATER VALUES OF GREATER THAN ONE INCH. ALSO GIVEN SEVERE THUNDERSTORM WATCH UNTIL 7PM FOR MOST OF THE CWA EXCEPT FOR DANIELS AND SHERIDAN COUNTIES...WILL NEED TO MONITOR FOR SOME STORMS TO PRODUCE LARGE HAIL...STRONG WINDS...AND VERY HEAVY RAINFALL. SPC STORM SCALE ENSEMBLE OF OPPORTUNITY PRODUCT SHOWS CONSISTENCY WITH LATEST HRRR AND NAM MODEL SOLUTIONS. EXPECT MOST OF THE ACTIVITY TO OCCUR PRIOR TO MIDNIGHT. BEYOND MIDNIGHT...CANNOT RULE OUT SHOWERS AND STORMS BUT THEY SHOULD REDUCE IN COVERAGE AND SEVERE POTENTIAL WILL LIKELY BE LIMITED BY THAT TIME. TUESDAY AND WEDNESDAY...ANY LEFTOVER SHOWERS AND THUNDERSTORMS WILL EXIT THE CWA DURING THE MORNING HOURS ON TUESDAY. THEREAFTER...MODELS DEPICT AN UPPER LEVEL RIDGE BUILDING INTO THE CWA WHICH WILL LEAD TO AN ABUNDANCE OF SUNSHINE...DRIER CONDITIONS...AND WARMING TEMPERATURES UNDER A REGIME OF LARGE SCALE SUBSIDENCE. DID NOT MAKE MANY CHANGES TO THIS PORTION OF THE FORECAST DUE TO THE PRIMARY CONCENTRATION ON THE SEVERE WEATHER POTENTIAL FOR THIS AFTERNOON INTO TONIGHT. WILL MAKE UPDATES AS NEEDED AS CONDITIONS WARRENT. MALIAWCO .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... SYNOPTIC SET UP... LONG TERM BEGINS WITH A LARGE HEAT DOME OVER THE DESERT SOUTHWEST AND INTERMOUNTAIN WEST. A RIDGE SPUR IS ANTICIPATED TO JUT OUT OF THE DOME OVER THE HIGH PLAINS OF MONTANA AND ALBERTA. A CLOSED LOW IS EXPECTED OVER THE COAST OF BRITISH COLUMBIA AND THE PACIFIC NORTHWEST. WEDNESDAY NIGHT INTO THURSDAY... DRY CONDITIONS ARE ANTICIPATED UNTIL THURSDAY AS NORTHEAST MONTANA COMES UNDER THE FULL OF AND INCREASING RIDGE. THURSDAY... THE AXIS OF THE RIDGE WILL PASS THROUGH AND ALLOW FOR A ISOLATED THUNDERSTORMS TO DEVELOP ON THE AXIS. THURSDAY ALSO LOOKS TO BE VERY WARM AHEAD OF THE AXIS WITH UPPER 90S AND POSSIBLE AS 850 MB TEMPERATURES REACH INTO THE 30* CELSIUS RANGE. THURSDAY NIGHT INTO SATURDAY...CLOSED LOW OVER THE PACIFIC NORTHWEST IS ANTICIPATED TO MOVE EAST THROUGH WEST MONTANA INTO THE HIGH PLAINS... EXITING THE RIDGE ALOFT OVER THE GREAT PLAINS. THIS WILL PLACE NORTHEAST MONTANA IN A SOUTHWEST FLOW WITH A WEAK TROUGHS AND SHORTWAVES MOVING THROUGH THE FLOW. A SHORTWAVE IS CURRENTLY TIMED ON FRIDAY WITH THE BASE OF THE LARGE TROUGH MOVING THROUGH SATURDAY HOWEVER... TIMING OF THESE WAVES COULD EASILY SHIFT AS THE LAST COUPLE RUNS HAVE ALREADY MOVED THEM AROUND. SATURDAY NIGHT ONWARD... THE TROUGH IS ANTICIPATED TO PASS OFF TO THE EAST AND REPRESS THE HEAT TO THE SOUTH WHILE A NEW RIDGE BUILDS OVER THE PACIFIC NORTHWEST. THIS WILL GENERATE ZONAL TO NORTHWEST FLOW ACROSS NORTHEAST MONTANA. CONDITIONS WILL BE DRY SLIGHTLY WITH A WEAK WARMING TREND. GAH && .AVIATION... VFR. ISOLATED THUNDERSTORMS CAN BE EXPECTED OFF AND ON THROUGH THE DAY WITH FEW SIGNIFICANT IMPACTS THROUGH 18Z. 21Z-06Z...HOWEVER A LINE OR COMPLEX OF SEVERE THUNDERSTORMS IS EXPECTED TO ROLL ACROSS NORTHEAST MONTANA. 23-01Z FOR KGGW... 00Z-02Z FOR KOLF... AND 01-03Z FOR KSDY/KGDV BASED ON THE CURRENT GUIDANCE. DO EXPECT SIGNIFICANT IMPACTS TO FLIGHT OPERATIONS LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS WITH THESE THUNDERSTORMS. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 308 AM MDT MON JUL 8 2013 MTZ016>027-059>062-091000- 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- 308 AM MDT MON JUL 8 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE FROM LATE THIS AFTERNOON THROUGH THE EVENING HOURS. LARGE HAIL... HIGH WINDS IN EXCESS OF 70 MPH AND HEAVY RAIN IS POSSIBLE WITH ANY OF THESE STORMS AS THEY PASS THROUGH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY 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
1226 PM MDT MON JUL 8 2013
MTZ016-060-081930-
PHILLIPS-
1226 PM MDT MON JUL 8 2013
THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A
SIGNIFICANT WEATHER ADVISORY FOR...
SOUTHERN PHILLIPS COUNTY IN NORTHEAST MONTANA...
UNTIL 130 PM MDT.
AT 1221 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 15 MILES SOUTH OF ZORTMAN...MOVING EAST AT 30
MPH.
HAIL UP TO ONE-HALF INCH IN DIAMETER IS EXPECTED WITH THIS STORM...
ALONG WITH HEAVY RAIN.
LOCATIONS IN THE ADVISORY INCLUDE...
FOURCHETTE...
LAT...LON 4782 10862 4800 10759 4765 10753 4765 10760
4763 10762 4765 10765 4763 10765 4763 10769
4756 10776 4756 10792 4760 10807 4757 10836
4761 10845 4759 10850 4761 10852 4761 10860
TIME...MOT...LOC 1826Z 263DEG 26KT 4770 10849
RAE
WEATHER.GOV/GLASGOWThe Glasgow radar (KGGW), 75 km away, was scanning. The volume nearest the first event began at 20:36 UTC.
22 hail, 17 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Trained spotter located 7 miles southeast of the Hell Creek Recreation Area reported golf ball sized hail covering Haxby Road.
Trained spotter reported quarter-sized hail and estimated wind gusts up to 50 mph.
Trained spotter reported walnut-sized hail.
Public reported hail up to the size of hen eggs fell for 10 minutes, breaking a skylight and several windows.
Trained spotter reported tea cup sized hail.
Trained spotter reported hail up to the size of golf balls broke windows, damaged siding, damaged a camper, and destroyed a pea crop.
Trained spotter reported walnut-sized hail.
Trained spotter reported that hail up to the size of baseballs fell for over 10 minutes, breaking windows and stripping most of the leaves from a tree.
Trained spotter reported golf ball sized hail.
Trained spotter reported golf ball sized hail.
Trained spotter reported hail up the size of quarters lasting 10 minutes.
Trained spotter reported golf ball sized hail.
Trained spotter reported quarter-sized hail.
Trained spotter measured a 70 mph wind gust.
Trained spotter reported quarter-sized hail covering the ground with leaves shredded from trees.
Trained spotter reported a few quarter-sized hail stones among the heavy rainfall.
Trained spotter measured a wind gust of 72.5 mph.
Trained spotter estimated wind gusts up to 70 mph along with heavy rain and a small amount of pea-sized hail.
Trained spotter and Law Enforcement reported that the old drive-in theater screen in Terry was mostly destroyed, tin structures sustained roof damage, and road signs were ripped off their poles.
Trained spotter estimated wind gusts up to 60 mph with branches falling out of their trees.
Trained spotter reported quarter-sized hail.
The Glendive AWOS measured a wind gust of 61 mph.
Public reported wind gusts up to 60 mph.
NWS storm survey estimated 95 mph wind gusts. Walls blown out of a free-standing metal building near mile marker 208 on I-94 with some sheet metal blown one-half mile down wind. A manufactured home rolled over near the same area.
NWS storm survey estimated wind gusts up to 95 mph from straight-line winds which damaged up-rooted large trees, removed roofing materials, and destroyed some small outbuildings.
Trained spotter reported quarter-sized hail and heavy rain.
Trained spotter estimated wind gusts of at least 60 mph. Large cottonwood trees bending with the wind.
Prairie County Dispatch office reported an over-turned semi truck on I-94 near mile marker 191 at the Fallon exit.
Public reported quarter-sized hail with heavy rain flooding the streets and running over the curbs.
Trained spotter reported quarter-sized hail causing damage to their garden.
Trained spotter estimated wind gusts up to 60 mph.
Trained spotter measured wind gusts up to 69 mph.
Trained spotter reported hail up to the size of quarters.
Trained spotter reported heavy rain and street flooding.
Trained spotter reported quarter-sized hail and wind gusts up to 45 mph.
Public estimated wind gusts up to 70 mph.
Trained spotter estimated wind gusts up to 60 mph.
Trained spotter reported half dollar sized hail destroyed their garden.
Trained spotter estimated wind gusts up to 70 mph with several 3-inch diameter tree branches downed.
Trained spotter estimated 70 mph winds with heavy rain reducing visibility to less than one-quarter mile.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2013Every state in 2013This day in weather historyWarnings in Montana, July 2013
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: 469590, 469681, 469690, 469692, 469694, 469696, 469697, 469700, 469792, 469799, 469800, 469805, 469806, 469813, 469808, 469810, 469815, 469870, 472292, 469871, 469812, 469872, 469873, 469875, 469877, 469880, 469893, 469899, 469882, 469883, 469887, 469888, 469884, 469587, 469886, 469894, 469895, 469892, 469896, 469897.