A weak surface low pressure system, including a cold front, a dryline, an ejecting upper level disturbance, and a moderately unstable atmosphere allowed strong thunderstorms to develop and become severe as they moved eastward through eastern 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 weak surface low pressure system, including a cold front, a dryline, an ejecting upper level disturbance, and a moderately unstable atmosphere allowed strong thunderstorms to develop and become severe as they moved eastward through eastern 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 Aug 28, 1:22 PM MST, 2 hours 23 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 222 PM MDT WED AUG 28 2013 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY... WITH SURFACE TEMPERATURES WELL INTO THE 90S ACROSS MOST OF THE CWA AND DEWPOINTS WELL INTO THE 60S AND SURFACE WINDS INCREASING FROM THE SOUTHEAST..THE STAGE IS BEING SET FOR STRONG TO SEVERE CONVECTIVE STORM DEVELOPMENT FROM THIS AFTERNOON THROUGH TONIGHT. CAPE VALUES IN EXCESS OF 1000J/KG ARE ALREADY IN PLACE OVER CENTRAL AND EASTERN ZONES OF OUR CWA. SEVERE THREATS SEEM TO BE MORE FOR DAMAGING WINDS AND LARGE HAIL AS SHEAR IS NOT AS STRONG AND LCL HEIGHTS ARE NOT AS LOW. CUMULUS CLOUDS ARE GROWING EARLY THIS AFTERNOON AS WE PREPARE FOR POSSIBLE SEVERE THUNDERSTORM OPERATIONS. HI-RES MODEL SOLUTIONS ARE INDICATING THAT THUNDERSTORM ACTIVITY COULD BE QUITE PROLONGED...MAYBE INTERMITTENTLY THROUGH THE LATE NIGHT HOURS ESPECIALLY OVER OUR EASTERN ZONES. TONIGHT THROUGH FRIDAY MORNING...A SHORT WAVE RIDGE PUSHES BACK INTO EASTERN MONTANA...CHASING THE STORMS AWAY. FRIDAY...FLOW ALOFT OVER OUR AREA BECOMES SOUTHWESTERLY AS A CLOSED LOW FROM THE BRITISH COLUMBIA COASTLINE RIDES UP AS AN OPEN WAVE OVER THE CANADIAN ROCKIES AND SENDS A COLD FRONT TOWARD OUR CWA FOR FRIDAY NIGHT. FOR NOW IT SEEMS THAT ANY PRECIPITATION WITH THIS FRIDAY SYSTEM WOULD BE CONFINED TO OUR NORTHERN AND EASTERN ZONES. BMICKELSON .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY... NOT TOO MANY CHANGES WERE MADE TODAY. IMPULSE HOWEVER AFFECTING THE AREA OVER THE WEEKEND LOOKS TO BE A BIT STRONGER THAN EXPECTED IN REGARDS TO TEMPS AND WINDS. MODELS WERE HINTING AT A FAIRLY STRONG RIDGE TO BUILD BACK INTO MONTANA NEXT WEEK. IF THIS TREND CONTINUES...TEMPS MAY HAVE TO BE WARMED AND POPS LOWERED. TFJ PREVIOUS DISCUSSION... THE EXTENDED FORECAST BEGINS FRIDAY NIGHT WITH NORTHEAST MONTANA UNDERNEATH ZONAL FLOW ALOFT AS UPPER LEVEL ENERGY DEPARTS EASTWARD INTO NORTH DAKOTA. THE 28/00Z MODEL GUIDANCE DEPICTS A MORE ROBUST SHORTWAVE SWEEPING ACROSS SOUTHERN SASKATCHEWAN AND EVENTUALLY MANITOBA SATURDAY AFTERNOON AND EVENING. THE FORCING FOR ASCENT WITH THIS FEATURE WILL LIKELY BE TOO FAR NORTHEAST TO AFFECT THE CWA. AN UPPER RIDGE IS EXPECTED TO BUILD ACROSS THE PACIFIC NORTHWEST AND INTO WESTERN MONTANA FOR SUNDAY WHICH WILL PLACE NORTHWEST FLOW ALOFT OVER THE CWA. ALL OF THIS WILL MEAN FAIRLY DRY CONDITIONS FOR NORTHEAST MONTANA AND A MODERATING TREND IN TEMPERATURES FOR SUNDAY WITH THE BUILDING RIDGE AFTER A RELIEF FROM THE HEAT ON SUNDAY. MONDAY AND TUESDAY...MODELS HAVE BACKED OFF ON PRECIPITATION CHANCES WITH THE RIDGE AMPLIFYING AND KEEPING THE AREA IN NORTHWEST FLOW ALOFT. MODEL 850MB TEMPERATURES WILL LIKELY BE WARM ENOUGH TO SUPPORT DAYTIME HIGHS RETURNING TO THE 90S FOR MONDAY AND PERHAPS NEAR 90 ON TUESDAY. WHILE SHORTWAVE ENERGY PROPAGATES THROUGH THE FLOW DURING THIS TIME...MODELS HANDLE THESE FEATURES DIFFERENTLY IN TERMS OF TIMING AND CHARACTERISTICS...ALTHOUGH WITH THE PLACEMENT OF THE UPPER LEVEL RIDGE...DO BELIEVE LARGE SCALE SUBSIDENCE SHOULD MAINTAIN DRY CONDITIONS ACROSS THE CWA. DID INSERT SLIGHT CHANCE POPS INTO THE GRIDS FOR TUESDAY WITH THE GFS IN PARTICULAR ADVERTISING SHORTWAVE ENERGY THROUGH THE CWA BUT NOT MUCH MOISTURE. PRECIPITATION CHANCES MAY BE A BIT OVERDONE. WILL EXPECT ADDITIONAL SHORTWAVE ENERGY TO PASS THROUGH THE AREA TOWARDS THE MIDDLE TO END OF NEXT WEEK BUT GIVEN MODEL DIFFERENCES THIS FAR OUT IN THE EXTENDED CONFIDENCE IS LOW. DID INSERT SLIGHT CHANCE POPS INTO THE GRIDS LATE WEDNESDAY TO COVER THIS POTENTIAL. FOR TEMPERATURES...INTRODUCED A GRADUAL COOLING TREND MID TO LATE WEEK PER RECENT GUIDANCE. AS SHORTWAVES BREAK DOWN THE RIDGE FROM EARLIER IN THE WEEK...AND HELP PUSH A THERMAL BOUNDARY SOUTHWARD...TEMPERATURES SHOULD RETURN TO AT OR BELOW NORMAL LEVELS BY THE MIDDLE TO END OF NEXT WEEK. MODEL GUIDANCE SHOWS CONSIDERABLY COOLER 850MB TEMPERATURES BY THE END OF NEXT WEEK AS WELL...CONSISTENT WITH THIS IDEA. MALIAWCO && .AVIATION... SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED TO MOVE EAST THROUGH THIS EVENING. TEMPORARY IFR/MVFR VISIBILITIES ARE POSSIBLE IF A HEAVIER THUNDERSTORM PASSES DIRECTLY OVER A TERMINAL LOCATION. LIGHT SOUTHEAST WINDS ARE EXPECTED EXCEPT ERRATIC AND GUSTY NEAR THUNDERSTORMS. TFJ && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 443 PM MDT WED AUG 28 2013 MTZ016>027-059>062-290600- 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- 443 PM MDT WED AUG 28 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TONIGHT A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL MIDNIGHT. ATMOSPHERIC CONDITIONS WILL FAVOR THE DEVELOPMENT OF STRONG TO SEVERE THUNDERSTORMS FROM THIS AFTERNOON THROUGH LATE TONIGHT WITH LARGE HAIL AND DAMAGING WINDS BEING THE MAIN THREATS ACROSS MOST OF NORTHEAST MONTANA. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY 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 310 PM MDT WED AUG 28 2013 MTZ022-282215- GARFIELD- 310 PM MDT WED AUG 28 2013 THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... WESTERN GARFIELD COUNTY IN NORTHEAST MONTANA... UNTIL 415 PM MDT. AT 307 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 13 MILES NORTHWEST OF SAND SPRINGS...MOVING NORTHEAST AT 20 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM. LOCATIONS IN THE ADVISORY INCLUDE... RURAL AREAS OF WESTERN GARFIELD COUNTY... 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 4756 10769 4734 10714 4710 10770 4718 10780 TIME...MOT...LOC 2110Z 212DEG 16KT 4720 10771 MICKELSON WEATHER.GOV/GLASGOW
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
353 PM MDT WED AUG 28 2013
MTZ022-282300-
GARFIELD-
353 PM MDT WED AUG 28 2013
THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A
SIGNIFICANT WEATHER ADVISORY FOR...
CENTRAL GARFIELD COUNTY IN NORTHEAST MONTANA...
UNTIL 500 PM MDT.
AT 350 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 10 MILES SOUTHWEST OF BRUSETT...MOVING NORTHEAST
AT 30 MPH.
HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.
LOCATIONS IN THE ADVISORY INCLUDE...
BRUSETT...
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 4728 10745 4735 10756 4766 10723 4767 10713
4740 10667
TIME...MOT...LOC 2153Z 226DEG 24KT 4735 10741
MICKELSON
WEATHER.GOV/GLASGOWThe Glasgow radar (KGGW), 74 km away, was scanning. The volume nearest the first event began at 22:47 UTC.
6 thunderstorm wind, 6 hail. Local standard time, as filed.
Public reported dead cottonwood tree blown down and grain auger blown over 4 miles SSW of the Hell Creek Recreation Area.
Trained Spotter reported walnut-sized hail.
Cooperative observer reported half dollar sized hail.
Trained spotter estimated half dollar sized hail.
Public reported wind gusts of 60 mph.
Prairie County Dispatch reported extensive property damage to windows, siding, and trees from winds and hail.
Trained spotter estimated hail up to size of quarters.
Trained spotter reported hail up to the size of quarters.
Trained spotter reported shingles ripped from a roof.
Trained spotter estimated quarter-sized hail and reported heavy rain.
Trained spotter reported wind gusts of 60 mph.
Trained spotter measured a 66 mph wind gust.
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, August 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: 475515, 475516, 475517, 475520, 475519, 475521, 475522, 475523, 475524, 475525, 475518, 475526.