A moderately-unstable environment combined with a fair amount of surface moisture to develop a few isolated storms across northeast Montana.
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 moderately-unstable environment combined with a fair amount of surface moisture to develop a few isolated storms across northeast Montana.
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 17, 8:53 AM MST, 7 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 953 AM MDT TUE JUL 17 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY... UPDATED THE FORECAST TO LOWER POPS AND SKY COVER ACROSS THE WESTERN PART OF THE CWA. WE WILL SEE POSSIBLE STRONG TO SEVERE THUNDERSTORM ACROSS OUR EASTERN ZONES. RSMITH PREVIOUS DISCUSSION...SOUTHWEST FLOW ALOFT WILL PREVAIL TODAY WITH LARGE UPPER RIDGE TO THE EAST AND UPPER LOW OVER THE PACIFIC NORTHWEST. ONE SHORTWAVE IN THE SW FLOW ALOFT IS CURRENTLY IN SE MONTANA AND IS BRING THUNDERSTORMS TO THAT AREA. THAT SYSTEM WILL MOVE TO THE EAST THIS MORNING. AN AREA OF LOW CLOUDS AND FOG THAT COVERS MOST OF SOUTHERN SASKATCHEWAN HAS DRIFTED INTO THE NORTHERN ZONES OF THE FORECAST AREA EARLY THIS MORNING. WILL MENTION AREAS OF FOG NORTH OF THE MISSOURI RIVER EARLY. THE FOG SHOULD LIFT WITH DAYTIME HEATING. A SHORTWAVE TROUGH WILL MOVE THROUGH EASTERN MONTANA THIS AFTERNOON AND EVENING AND LIFT A WARM FRONT THROUGH THE AREA. THERE SHOULD BE ENOUGH BREAKS IN THE CLOUDS TODAY FOR GOOD DAYTIME HEATING TO DESTABILIZE THE ATMOSPHERE. THE MOST UNSTABLE AIR WILL BE IN THE EAST WITH CAPE NEAR 1000 J/KG AND LIFTED INDICIES AS LOW AS -5 THIS AFTERNOON AND EVENING. AGREE WITH SPC SLIGHT RISK IN THIS AREA. WILL MENTION THE POSSIBILITY OF SEVERE THUNDERSTORMS OVER THE EASTERN HALF OF THE FORECAST AREA. WITH PRECIPITABLE WATER APPROACHING 1.6 INCHES...COULD ALSO SEE LOCALLY HEAVY RAIN. THE WAVE MOVES TO THE EAST OVERNIGHT AND UPPER RIDGE BUILDS INTO MONTANA FOR WEDNESDAY AND THURSDAY WITH HOT AND MAINLY DRY WEATHER. THUNDERSTORMS MAY LINGER IN THE EAST WEDNESDAY MORNING WITH DEPARTING WAVE. ALSO...WEAK WAVE MOVING OVER THE RIDGE THURSDAY AFTERNOON MAY BE ENOUGH TO POP A THUNDERSTORM IN THE NORTHEAST. OTHERWISE...LOOK FOR HOT AND DRY WEATHER WEDNESDAY AND THURSDAY. FORRESTER .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY... THE LONG TERM FORECAST PERIOD CONTINUES THE EPIC STRUGGLE BETWEEN THE STABLE...HOT...HIGH PRESSURE SYSTEM OVER THE HIGH PLAINS AND THE LOW PRESSURE SYSTEM AND ASSOCIATED SHORT WAVE DISTURBANCES RIDING UP AND OVER THE NORTHERN ROCKIES. THURSDAY NIGHT THROUGH FRIDAY...THE HIGH PLAINS HIGH PRESSURE KEEPS MOST PRECIPITATION AWAY FROM NORTHEAST MONTANA. FRIDAY NIGHT THROUGH SATURDAY...A SHORT WAVE DISTURBANCE BREAKS DOWN THAT RIDGE A BIT AND SPREADS SOME SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST MONTANA WITH SOME LOCATIONS LOOKING TO RECEIVE A THIRD OF AN INCH OF RAIN. AFTER THIS...THE UPPER LEVEL HIGH PRESSURE AREA IS JUST NEVER THE SAME...SHOVED AWAY TOWARD THE SOUTH AS A SLIGHTLY MORE ZONAL UPPER LEVEL FLOW TAKES OVER FOR MONTANA. SATURDAY NIGHT THROUGH SUNDAY SEEMS TO BE A QUIET PERIOD BETWEEN DISTURBANCES. SUNDAY NIGHT THROUGH MONDAY NIGHT...ANOTHER LOW PRESSURE SYSTEM FROM BRITISH COLUMBIA SLIDES EASTWARD ALONG THE INTERNATIONAL BORDER BRINGING SOME SCATTERED SHOWERS AND THUNDERSTORMS. TUESDAY THROUGH WEDNESDAY...A MORE PURE ZONAL FLOW KEEPS MONTANA DRY. FRIDAY THIS WEEK WILL BE THE HOTTEST DAY OF THE FORECAST AHEAD OF THE FIRST SHORT WAVE DISTURBANCE. LITTLE RELIEF IN TEMPERATURES TO BE FOUND THROUGH THE REMAINDER OF THE FORECAST PERIOD. EXTENDED MODELS IN FAIRLY GOOD AGREEMENT THROUGH THIS COMING WEEKEND...THEN SOME TIMING DIFFERENCES BEGIN TO SHOW TOWARD THE END OF THE FORECAST PERIOD REDUCING FORECAST CONFIDENCE FOR THAT TIME FRAME. BMICKELSON && .AVIATION... THIS MORNING LOW CLOUDS WILL AFFECT KSDY AND KGDV BEFORE MOVING OFF TO THE EAST BY AFTERNOON. A BROAD SURFACE TROUGH WILL MAINTAIN NW WINDS AT AROUND 10KTS THAT WILL BECOME EASTERLY IN THE AFTERNOON. SOUTHWESTERLY FLOW ALOFT CONTINUES TO CHANNEL MOISTURE INTO MODERATELY UNSTABLE AIR OVER NORTHEAST MONTANA TODAY. THIS IS A GOOD SETUP FOR AFTERNOON AND EVENING THUNDERSTORMS. THE STRONGEST STORMS ARE EXPECTED TO DEVELOP EAST OF KGGW WITH THE POSSIBILITY OF A SUPER-CELL OR TWO. SCT && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 237 PM MDT TUE JUL 17 2012 MTZ016-017-021-022-059>061-181000- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- PETROLEUM-GARFIELD-NORTHERN PHILLIPS-SOUTHWEST PHILLIPS- NORTHERN VALLEY- 237 PM MDT TUE JUL 17 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY HOT TEMPERATURES ARE FORECASTED WEDNESDAY...THURSDAY AND FRIDAY. MOST AREAS WILL HAVE HIGHS IN THE MID 90S ON WEDNESDAY...NEAR 100 ON THURSDAY AND BETWEEN 95 AND 100 ON FRIDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ018>020-023>027-062-181000- DANIELS-SHERIDAN-WESTERN ROOSEVELT-MCCONE-RICHLAND-DAWSON-PRAIRIE- WIBAUX-EASTERN ROOSEVELT- 237 PM MDT TUE JUL 17 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT SCATTERED TO NUMEROUS THUNDERSTORMS CAN BE EXPECTED THIS AFTERNOON AND EVENING. SOME STORMS MAY BECOME SEVERE ACROSS THE YELLOWSTONE VALLEY. LOCALLY HEAVY RAIN IS ALSO POSSIBLE. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY HOT TEMPERATURES ARE FORECASTED WEDNESDAY...THURSDAY AND FRIDAY. MOST AREAS WILL HAVE HIGHS IN THE MID 90S ON WEDNESDAY...NEAR 100 ON THURSDAY AND BETWEEN 95 AND 100 ON FRIDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Glasgow radar (KGGW), 128 km away, was scanning. The volume nearest the first event began at 23:14 UTC.
1 thunderstorm wind. Local standard time, as filed.
A wind gust of 69 mph was measured at the Malta South US-191 DOT site.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2012Every state in 2012This day in weather historyWarnings in Montana, July 2012
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: 402020.