A strong low pressure system over the northern plains, allowed very strong winds to be focused across northeast Montana.
Every event with a place to put it; 12 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 low pressure system over the northern plains, allowed very strong winds to be focused 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 May 5, 7:44 PM MST, 7 hours 41 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 844 PM MDT SAT MAY 5 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT... MODERATELY STRONG COLD FRONT HAS NOW MOVED E THRU OUR ENTIRE CWA...LEAVING BEHIND A COOLER AIRMASS WITH MOST TEMPS 45-50 AT 8 PM. THE MAIN PRECIP AREA NOW INTO OUR E. AMOUNTS AS HIGH AS ALMOST AN INCH IN OUR N REPORTED. VISIBLE SATELLITE WAS SHOWING A DRY SLOT ENTERING OUR W...BUT NOT PERFECTLY DRY THOUGH...AS THERE ARE SOME SHOWERS IN IT. SURFACE PRESSURE GRADIENTS HAVE WEAKENED A LOT...AND WITH LOSS OF HOOKUP...RESULTING WINDS HAVE DIMINISHED WELL BELOW ADVISORY CRITERIA...SO LAKE WIND ADVISORY CANCELLED. SATELLITE CHANNELS SHOW VERY WELL TOO THE LOW PRESSURE CIRCULATION CENTER OVER SE AB WHICH WILL MOVE SLOWLY E ALONG THE SK/MT BORDER OVERNIGHT. WRAP-AROUND OR BACKWASH MOISTURE WILL BRING SOME INCREASE IN SHOWERS LATE TONIGHT. MAIN UPDATE TO ADJUST POPS. SIMONSEN PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...THE LATEST 12Z MODEL RUNS HAVE THE BEST AGREEMENT TO DATE FOR THIS NEAR VERTICALLY STACKED SYSTEM. THE PREVIOUS MODEL RUNS HAD BOTH THE ECMWF AND NAM 500 MB AND 700 MB LOWS CENTERS STACKED OVER SOUTHERN SASKATCHEWAN. THE LATEST 12Z RUNS ON BOTH MODELS ARE MORE IN LINE WITH WHAT THE GFS HAS BEEN SAYING OVER THE LAST SEVERAL MODEL RUNS. THE GFS ENSEMBLE MEAN IS RIGHT IN LINE WITH THE NAM AND ECMWF OVER THROUGH MONDAY SO USED THIS AS MY GUIDE IN MAKING THE FORECAST. FOR THIS EVENING DRIER AIR WILL MOVE IN BEHIND THE COLD FRONT SHOULD KEEP THE RAIN TOTALS ACROSS THE WEST THIS EVENING TO LESS THEN A TENTH OF AN INCH. A LAKE WIND ADVISORY REMAINS IN EFFECT FOR FORT PECK LAKE THROUGH THE EARLY EVENING. THE WINDS WILL DIMINISH AROUND SUNSET THIS EVENING. ACCORDING TO THE MODELS THE DRY SLOT REMAINS ACROSS THE WHOLE AREA AFTER MIDNIGHT. THIS DRY AIR WILL CONTINUE TO WRAP UP INTO THE VERTICALLY STACKED LOW PRESSURE SYSTEM OVER THE INTERNATIONAL BOARDER. I THINK ANY LINGERING SHOWERS WILL END AROUND MIDNIGHT ACROSS THE AREA. SUNDAY THROUGH MONDAY...WITH AGREEMENT IN THE MODELS...LIKE THE ECMWF AND NAM MODEL RUNS SHIFTING THE STACKED LOW PRESSURE SYSTEM TO LOOK LIKE THE LAST SEVERAL GFS MODEL RUNS...DECIDED TO LAUNCH A HIGH WIND WATCH FOR SUNDAY. FOR THE LAST SEVERAL DAYS THE GFS HAS HAD THE STRONGEST WIND SPEEDS FOR SUNDAY. LOOKING AT NAM/GFS/SREF MODEL SOUNDING ON BUFKIT SUSTAINED WIND SPEED BETWEEN 35 TO 40 KNOTS WILL BE COMMON ON SUNDAY. WINDS GUSTS WILL AVERAGE BETWEEN 45 AND 55 KNOTS WITH OCCASIONAL GUSTS OVER 60 KNOTS SOUTH OF THE MISSOURI RIVER IN THE AFTERNOON. WILL LET THE NIGHT CREW TAKE ANOTHER LOOK AT THE 00Z MODEL RUNS FOR THIS EVENT BUT A HIGH WIND WARNING LOOK LIKE A GOOD BET FOR SUNDAY. RSMITH .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... UPPER RIDGING WILL DOMINATE TUESDAY INTO WEDNESDAY...BRINGING WARM AND DRY CONDITIONS. A POTENT COLD FRONT WILL PUSH THROUGH ON THURSDAY...USHERING IN UNSETTLED CONDITIONS LASTING INTO THURSDAY NIGHT. FRIDAY AND BEYOND UPPER RIDGING WILL PUSH BACK IN FROM THE NORTHWEST...FOR A RETURN TO DRY CONDITIONS WITH WARMING TEMPS. FORECAST MODELS AND THE GOING FORECAST ARE IN GOOD SHAPE DEPICTING ALL OF THESE FEATURES. ONLY REAL TWEAKS WERE TO CONTINUE TO TREND UP TEMPS WITH THE RIDGING ON TUESDAY INTO WEDNESDAY. GILCHRIST PREVIOUS DISCUSSION...UPPER LEVEL RIDGE WILL BRING DRY AND MAINLY SUNNY WEATHER WITH A WARMING TREND TUESDAY AND WEDNESDAY. WEDNESDAY WILL BE THE WARMEST DAY WITH THERMAL RIDGE OVER EASTERN MONTANA. THE RIDGE MOVES TO THE EAST WEDNESDAY NIGHT AND STRONG COLD FRONT MOVES THROUGH THE AREA ON THURSDAY. STRONG SHORTWAVE WITH MODELS DIFFERING ON HOW MUCH MOISTURE THERE WILL BE. WILL MENTION A CHANCE OF SHOWERS FOR NOW. WILL SEE GUSTY NORTHWEST WINDS BEHIND THE FRONT. NORTHWEST FLOW ALOFT WILL LINGER BEHIND THE WAVE FRIDAY AND SATURDAY WITH UPPER RIDGE TO THE WEST. LOOK FOR DRY WEATHER WITH NEAR NORMAL TEMPERATURES. FORRESTER && .AVIATION... CIGS ARE GENERALLY ON THE INCREASE ACROSS NORTHEAST MONTANA AND SHOULD BE VFR THROUGH 15Z. SOME SHOWERS WILL CONTINUE THROUGH AT LEAST 09Z ACROSS NORTHEASTERN MONTANA BUT NOTHING SIGNIFICANT AT THE TAF SITES. THERE COULD BE SOME MVFR CIGS WITH WDLY SCT SHOWERS AFTER 15Z AT THE TAF SITES BUT THE BIGGEST CONCERN WILL BE THE WINDS. BY 18Z MOST OF THE SITES WILL BE AT 35G50 KTS THROUGH SUNSET. WINDS WILL BE VEERING FROM WEST TO NORTHWEST THROUGH THE LOWER 5K FEET WITH SPEEDS OF 50 TO 60 KTS THROUGH 10K FEET. FRANSEN && .GLASGOW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM 6 AM MDT SUNDAY THROUGH SUNDAY EVENING FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY... WESTERN ROOSEVELT...PETROLEUM...GARFIELD...MCCONE...RICHLAND... DAWSON...PRAIRIE...WIBAUX...NORTHERN PHILLIPS...SOUTHWEST PHILLIPS...NORTHERN VALLEY...EASTERN ROOSEVELT. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 400 AM MDT SUN MAY 6 2012 MTZ016-017-020>027-059>062-071000- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE-RICHLAND-DAWSON- PRAIRIE-WIBAUX-NORTHERN PHILLIPS-SOUTHWEST PHILLIPS- NORTHERN VALLEY-EASTERN ROOSEVELT- 400 AM MDT SUN MAY 6 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT A HIGH WIND WARNING IS IN EFFECT UNTIL 9 PM. WEST WINDS SHIFTING TO NORTHWEST WILL INCREASE TO 35 TO 45 MPH. SOME GUSTS MAY REACH AS HIGH AS 60 MPH. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY 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. MTZ018-019-071000- DANIELS-SHERIDAN- 400 AM MDT SUN MAY 6 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT NORTHWEST WINDS 25 TO 35 MPH WITH GUSTS TO 50 MPH CAN BE EXPECTED TODAY. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY 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.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
406 AM MDT SUN MAY 06 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0325 AM NON-TSTM WND GST 7 SE DEVILS CREEK RECRE 47.56N 107.53W
05/06/2012 M58 MPH GARFIELD MT MESONET
SOUTH SAWMILL CREEK RAWS
&&
JBThe national radar mosaic for the moment the first event began.
12 high wind. Local standard time, as filed.
Sustained wind speeds above 40 mph were common across the county. The South Sawmill Creek RAWS site measured a 58 mph wind gust at 3:25 AM MDT, then measured a 59 mph gust at 11:25 AM MDT.
Winds near and above 40 mph were common across the area with a maximum wind gust of 64 mph measured at the Malta South US-191 DOT site.
Winds near and above 40 mph were common across the area with a maximum wind gust of 64 mph measured at the Malta South US-191 DOT site.
Sustained winds between 40 and 45 mph were common across the area for most of the day, while maximum 61 mph wind gusts were measured at the Charlie Creek mesonet site both at 2:18 PM and 5:03 PM MDT.
Sustained winds between 35 and 45 mph were common across the area for most of the day, while maximum 61 mph wind gusts were measured at the Charlie Creek mesonet site, right on the border between Richland and eastern Roosevelt counties both at 2:18 PM and 5:03 PM MDT.
Winds between 35 and 45 mph were common throughout most of the day at the Beaver Hill I-94 DOT site.
Sustained winds near and above 40 mph were measured at the Whitewater mesonet site.
Sustained winds near 40 mph were common across the area, while a 60 mph wind gust was measured at the King Coulee mesonet sensor at 2:44 PM MDT.
Sustained winds between 40 and 45 mph were common across the area, while a 58 mph wind gust was measured at the handar mesonet sensor just east of the Fort Peck Dam at 1:30 PM MDT.
Sustained winds above 40 mph were common across the area, while a maximum 59 mph wind gust was measured at the Mcdonalds DOT site at 2:40 PM MDT.
Winds in excess of 40 mph were common while a maximum wind gust of 61 mph was measured at the Lindsay Divide Hwy 200-S DOT site at 5:00 PM MDT.
Co-operative observer reported a 62 mph wind gust.
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, May 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: 377991, 377983, 385894, 384076, 384079, 384082, 377978, 384074, 384075, 384080, 384081, 384083.