5 inches fell, swelling creeks and rivers.
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.
Heavy rain fell in many areas of Valley, McCone, Garfield and Dawson counties where up to 2.5 inches fell, swelling creeks and rivers.
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 10, 10:26 AM MST, 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 1126 AM MDT TUE MAY 10 2011 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY... UPDATE...BULK OF THE UPDATE THIS MORNING REVOLVED AROUND THE MOUNTING HYDRO CONCERNS. ISSUED AN ADDITIONAL SMALL STREAM FLOOD ADVISORY FOR THE THE SOUTHERN REACHES OF THE BIG SHEEP MTNS. ALSO ISSUED A FLOOD WATCH FOR THE MILK RIVER AT GLASGOW AND NASHUA AS SHARP RISES ARE EXPECTED. THE ACTUAL FORECAST WAS IN OVERALL EXCELLENT SHAPE. ONLY REAL TWEAK WAS TO LOWER TEMPS A BIT GIVEN ONGOING PRECIPITATION AND CLOUD COVER. GILCHRIST PREVIOUS DISCUSSION...DEEP CIRCULATION DEVELOPING NORTH OF THE BLACK HILLS WITH MODERATE TO LOCALLY HEAVY RAIN CONTINUING ON THE NORTH AND WEST SIDE OF THE SYSTEM OVER EASTERN MONTANA. INTENSE PRECIPITATION WILL CONTINUE TODAY AS THE LOW LIFTS ACROSS WESTERN NORTH DAKOTA THEN TAPERING OFF LATE TONIGHT. CONVECTION HAS WEAKENED WHICH WILL SLOW ACCUMULATIONS TODAY BUT PRECIPITATION AMOUNTS FOR THE EVENT STILL EXPECTED TO BE IN THE 1-3 INCH RANGE. FLOOD WATCH IN EFFECT FOR THE SOUTHEAST PORTION OF THE CWA AS WELL AS A FLOOD WARNING AND A FEW FLOOD ADVISORIES FOR TODAY FROM RAINFALL OVERNIGHT. NORTH WINDS ALSO BEGINNING TO INCREASE AS THE LOW ORGANIZES. LAKE WIND ADVISORY LOOKS ON TRACK AND SOME CONCERN FOR WINDS APPROACHING HIGH WIND LEVELS ESPECIALLY ACROSS THE NORTHEAST ZONES. FOR NOW MID LEVEL WINDS NOT QUITE STRONG ENOUGH AND LAPSE RATES ON THE LOW SIDE TO REACH FULL MIXING POTENTIAL TODAY. PROVIDED THE SYSTEM TRACKS ACROSS WESTERN NORTH DAKOTA TODAY AND DOES NOT STALL OUT AND DEEPEN...EXPECT WINDS TO REMAIN BELOW THE CRITERIA FOR HIGH WIND. SNOW POTENTIAL AT THE TAIL END OF THE SYSTEM CONTINUES TO DIMINISH AS WARM LAYER FAIRLY DEEP WITH THIS SYSTEM...PUTTING ICE PRODUCTION ZONE IN THE UPPER PORTIONS OF THE STORM SYSTEM. NOT EXPECTING ENOUGH COLD AIR ADVECTION OR DYNAMIC COOLING TO LOWER THE SNOW LEVEL LOW ENOUGH TO OVERCOME THE DRYING ALOFT. SO EXPECT MORE COLD RAIN THAN SNOW AT THIS POINT. A LITTLE RAIN MAY CONTINUE INTO WEDNESDAY OVER THE EASTERN ZONES WITH THE STORM SYSTEM LIFTING INTO MANITOBA. HIGH PRESSURE BEGINS BUILDING INTO WESTERN MONTANA AND WILL PUSH DRY AND WARMER AIR EASTWARD THROUGH THURSDAY. EBERT .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY... THURSDAY NIGHT THROUGH SATURDAY... A BATTLE OF AIRMASSES WILL BE SETTING UP BETWEEN A STALLED COOL CORE TROUGH OVER THE DAKOTAS AND A RELATIVELY WARMER RIDGE OVER WESTERN MONTANA. NORTHEASTERN MONTANA WILL BE SANDWICHED BETWEEN THESE TWO FEATURES ALLOWING UNSEASONABLY COOL TEMPERATURES AND DRY CONDITIONS. SATURDAY NIGHT THROUGH MONDAY... THE COOL CORE TROUGH IS EXPECTED TO EJECT OFF TO THE NORTH AND ALLOW A STRONG DEEPENING TROUGH OVER THE PACIFIC NORTHWEST TO NUDGE THE WESTERN MONTANA RIDGE OVER THE REGION. LOOK FORWARD TO WARMING CONDITIONS... WITH A CHANCE AT AFTERNOON THUNDERSTORMS THROUGH THIS PERIOD AS SHORTWAVES BEGIN FLINGING ACROSS EASTERN MONTANA AND TAPPING INTO THE WARM SURFACE LAYER. MONDAY NIGHT ONWARD... CONFIDENCE BEGINS TO DECREASE HERE WITH MODEL BREAKDOWN... BUT GIVEN THE STRENGTH OF THE DEVELOPING TROUGH ACROSS THE WESTERN THIRD OF THE COUNTRY THE TROUGH IS EXPECTED TO EJECT OUT OVER MONTANA AND GENERATE A COOL AND RAINY PATTERN WITH VARIABLY CLOUDY SKIES. GAH && .AVIATION... MVFR TO IFR CEILINGS THROUGH TODAY AS A LARGE SPRING STORM SYSTEM DEEPENS OVER THE NORTHERN HIGH PLAINS AND MOVES EAST. RAIN SHOWERS FOR ALL SITES AND ISOLATED THUNDER WILL BE POSSIBLE NEAR KGDV AND KSDY THROUGHOUT THE DAY. WINDS ARE ALSO EXPECTED TO RAMP UP TODAY BETWEEN SHOWERS TO 20 TO 25 KTS SUSTAINED OUT OF THE NORTH WITH GUSTS UPWARDS OF 35 KTS...SLOWLY CALMING BY MIDNIGHT. GAH/BLM && .HYDROLOGY... SIGNIFICANT RAINFALL CONTINUES TO FALL ACROSS NORTHEAST MONTANA... WITH MORE ON THE WAY TODAY. AT THIS TIME THE HEAVIEST RAINFALL IS EXPECTED EAST OF A SCOBEY TO GLASGOW TO WINNETT LINE. RISES CAN BE EXPECTED ON THE MILK...YELLOWSTONE...REDWATER...MUSSELSHELL...AND POPLAR RIVERS...AS WELL AS ON BIG MUDDY CREEK. SMALLER CREEKS WILL ALSO SEE RISES...SUCH AS BEAVER CREEK IN WIBAUX COUNTY. PERSONS ARE ADVISED TO KEEP A WATCHFUL EYE FOR CHANGING RIVER AND STREAM CONDITIONS THROUGH MIDWEEK. GILCHRIST/RAE && .GLASGOW WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH THIS EVENING FOR GARFIELD...MCCONE... DAWSON...PRAIRIE...WIBAUX. LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK LAKE. FLOOD WATCH THROUGH LATE TONIGHT FOR SHERIDAN...WESTERN ROOSEVELT...RICHLAND...EASTERN ROOSEVELT. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 1134 AM MDT TUE MAY 10 2011 MTZ016>018-059>061-111200- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- DANIELS-NORTHERN PHILLIPS-SOUTHWEST PHILLIPS-NORTHERN VALLEY- 1134 AM MDT TUE MAY 10 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT A LAKE WIND ADVISORY FOR FORT PECK LAKE CONTINUES THROUGH THIS EVENING. PERIODS OF MODERATE TO HEAVY RAIN WILL CONTINUE TODAY BUT TAPER OFF FROM WEST TO EAST LATE TONIGHT. MOST LOCATIONS HAVE ALREADY MEASURED ONE TO TWO INCHES OF RAIN. AN ADDITIONAL ONE TO TWO INCHES OF RAIN WILL BE POSSIBLE THROUGH THE OVERNIGHT HOURS. THIS WILL LIKELY RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE AREAS. MINOR FLOODING OF SMALL CREEKS AND STREAMS WILL ALSO BE POSSIBLE. NORTH WINDS WILL ALSO INCREASE TODAY AND COMBINED WITH THE RAIN WILL POSE A SIGNIFICANT HAZARD TO YOUNG LIVESTOCK. RANCHERS ARE ADVISED TO TAKE NECESSARY PRECAUTIONS TO PROTECT NEWBORN CALVES. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SHARP RISES FOR MAIN STEM RIVERS ARE EXPECTED THROUGH THIS WEEK IN RESPONSE TO THIS PERSISTENT HEAVY RAINFALL. REFER TO THE NUMEROUS HYDROLOGY FORECAST PRODUCTS FOR THE LATEST INFORMATION. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ019>027-062-111200- SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE-RICHLAND- DAWSON-PRAIRIE-WIBAUX-EASTERN ROOSEVELT- 1134 AM MDT TUE MAY 10 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT A LAKE WIND ADVISORY FOR FORT PECK LAKE CONTINUES THROUGH THIS EVENING. PERIODS OF MODERATE TO HEAVY RAIN SHOWERS WILL CONTINUE TODAY BUT TAPER OFF FROM WEST TO EAST LATE TONIGHT. MOST LOCATIONS HAVE ALREADY MEASURED TWO TO THREE INCHES OF RAIN. AN ADDITIONAL TWO INCHES OF RAIN WILL BE POSSIBLE THROUGH THE OVERNIGHT HOURS. THIS WILL LIKELY RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE AREAS. MINOR FLOODING OF SMALL CREEKS AND STREAMS WILL ALSO BE POSSIBLE. NORTH WINDS WILL ALSO INCREASE TODAY AND COMBINED WITH THE RAIN WILL POSE A SIGNIFICANT HAZARD TO YOUNG LIVESTOCK. RANCHERS ARE ADVISED TO TAKE NECESSARY PRECAUTIONS TO PROTECT NEWBORN CALVES. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SHARP RISES FOR MAIN STEM RIVERS ARE EXPECTED THROUGH THIS WEEK IN RESPONSE TO THIS PERSISTENT HEAVY RAINFALL. REFER TO THE NUMEROUS HYDROLOGY FORECAST PRODUCTS FOR THE LATEST INFORMATION. .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
702 AM MDT TUE MAY 10 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0520 AM HEAVY RAIN SIDNEY 47.72N 104.16W
05/10/2011 M1.75 INCH RICHLAND MT CO-OP OBSERVER
RAINFALL TOTAL FROM 520AM YESTERDAY TO 520AM TODAY. STILL
RAINING.
0544 AM HEAVY RAIN 13 NW MCCLOUD 47.03N 105.80W
05/10/2011 M1.34 INCH PRAIRIE MT MESONET
RAINFALL TOTAL FROM 544AM YESTERDAY TO 544AM TODAY.
0600 AM HEAVY RAIN GLASGOW 48.20N 106.64W
05/10/2011 M1.03 INCH VALLEY MT OFFICIAL NWS OBS
RAINFALL TOTAL FROM 6AM YESTERDAY TO 6AM TODAY
0600 AM HEAVY RAIN GLENDIVE 47.11N 104.71W
05/10/2011 M2.67 INCH DAWSON MT CO-OP OBSERVER
RAINFALL TOTAL FROM 6AM YESTERDAY TO 6AM TODAY. RAIN IS
STILL FALLING.
0600 AM HEAVY RAIN JORDAN 47.32N 106.91W
05/10/2011 M1.45 INCH GARFIELD MT ASOS
RAINFALL TOTAL FROM 6AM YESTERDAY TO 6AM TODAY.
0600 AM HEAVY RAIN WOLF POINT 48.09N 105.64W
05/10/2011 M1.33 INCH ROOSEVELT MT ASOS
RAINFALL TOTAL FROM 6AM YESTERDAY TO 6AM TODAY.
0600 AM HEAVY RAIN SIDNEY 47.72N 104.16W
05/10/2011 M1.32 INCH RICHLAND MT AWOS
RAINFALL TOTAL FROM 6AM YESTERDAY TO 6AM TODAY.
0600 AM HEAVY RAIN GLENDIVE 47.11N 104.71W
05/10/2011 M1.80 INCH DAWSON MT AWOS
RAINFALL TOTAL FROM 6AM YESTERDAY TO 6AM TODAY.
0630 AM HEAVY RAIN 4 SW HINSDALE 48.35N 107.15W
05/10/2011 M1.41 INCH VALLEY MT CO-OP OBSERVER
RAINFALL TOTAL SINCE AROUND 6AM YESTERDAY. LIGHT RAIN IS
FALLING.
0630 AM HEAVY RAIN 10 N LINDSAY 47.36N 105.15W
05/10/2011 M1.30 INCH DAWSON MT TRAINED SPOTTER
RAIN TOTAL SINCE 8PM YESTERDAY AND IS STILL RAINING.
WATER IS RUNNING DOWN THE DRIVEWAY AND CREEKS ARE RISING.
0650 AM HEAVY RAIN JORDAN 47.32N 106.91W
05/10/2011 M2.15 INCH GARFIELD MT TRAINED SPOTTER
THREE DAY RAINFALL TOTAL. STILL RAINING. WATER IS RUNNING
INTO BASEMENT.
0650 AM HEAVY RAIN WESTBY 48.87N 104.05W
05/10/2011 M1.35 INCH SHERIDAN MT CO-OP OBSERVER
RAINFALL TOTAL FROM 650AM YESTERDAY TO 650AM TODAY. STILL
RAINING.
0650 AM HEAVY RAIN 12 S CULBERTSON 47.97N 104.52W
05/10/2011 M1.40 INCH RICHLAND MT TRAINED SPOTTER
RAINFALL TOTAL SINCE 10PM YESTERDAY AND IS STILL RAINING.
&&
ASCHNETZPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
737 AM MDT TUE MAY 10 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0622 AM HEAVY RAIN 8 WNW U L BEND 47.53N 108.05W
05/10/2011 M1.61 INCH PETROLEUM MT MESONET
RAINFALL TOTAL FROM 622AM YESTERDAY TO 622AM TODAY AT THE
CHAIN BUTTES RAWS.
0624 AM HEAVY RAIN 17 SE HOYT 46.78N 104.58W
05/10/2011 M1.80 INCH WIBAUX MT MESONET
RAINFALL TOTAL FROM 624AM YESTERDAY TO 624AM TODAY AT THE
PINE HILL RAWS.
0625 AM HEAVY RAIN 7 SE DEVILS CREEK RECRE 47.56N 107.53W
05/10/2011 M1.95 INCH GARFIELD MT MESONET
RAINFALL TOTAL FROM 625AM YESTERDAY TO 625AM TODAY AT THE
SOUTH SAWMILL CREEK RAWS.
0641 AM HEAVY RAIN 17 N WINNETT 47.24N 108.36W
05/10/2011 M1.13 INCH PETROLEUM MT MESONET
RAINFALL TOTAL FROM 641AM YESTERDAY TO 641AM TODAY AT THE
DRY BLOOD CREEK RAWS.
0642 AM HEAVY RAIN 5 S TAMPICO 48.23N 106.84W
05/10/2011 U0.00 INCH VALLEY MT TRAINED SPOTTER
ANTELOPE CREEK WAS BARELY RUNNING YESTERDAY AND IS NOW
RUNNING BANKFUL AND BACKING UP INTO THE LOWLANDS.
0644 AM FREEZING RAIN 13 NW MCCLOUD 47.03N 105.80W
05/10/2011 M1.60 INCH PRAIRIE MT MESONET
RAINFALL TOTAL FROM 644AM YESTERDAY TO 644AM TODAY AT THE
BIG SHEEP MOUNTAIN RAWS.
0644 AM HEAVY RAIN 14 NNW HELL CREEK RECRE 47.80N 107.02W
05/10/2011 M1.62 INCH VALLEY MT MESONET
RAINFALL TOTAL FROM 644AM YESTERDAY TO 644AM TODAY AT THE
KING COULEE RAWS.
0658 AM HEAVY RAIN 4 ENE PLENTYWOOD 48.79N 104.48W
05/10/2011 M1.80 INCH SHERIDAN MT MESONET
RAINFALL TOTAL FROM 658AM YESTERDAY TO 658AM TODAY AT THE
MEDICINE LAKE RAWS.
0700 AM HEAVY RAIN GLENDIVE 47.11N 104.71W
05/10/2011 M2.26 INCH DAWSON MT TRAINED SPOTTER
RAINFALL TOTAL FROM 7AM YESTERDAY TO 7AM TODAY. STILL
RAINING.
0713 AM HEAVY RAIN 3 S CRANE 47.53N 104.27W
05/10/2011 M2.10 INCH RICHLAND MT TRAINED SPOTTER
RAINFALL TOTAL FROM 4PM YESTERDAY TO 7AM TODAY. STILL
RAINING.
0718 AM HEAVY RAIN 1 NNW SPROLE 48.13N 105.07W
05/10/2011 M1.31 INCH ROOSEVELT MT MESONET
RAINFALL TOTAL FROM 718AM YESTERDAY TO 718AM TODAY AT THE
POPLAR RAWS.
&&
ASCHNETZPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
821 AM MDT TUE MAY 10 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM HEAVY RAIN 2 WSW GLENDIVE 47.10N 104.75W
05/10/2011 M2.24 INCH DAWSON MT TRAINED SPOTTER
RAINFALL TOTAL AS OF 7AM. LIGHT RAIN IS FALLING.
0800 AM HEAVY RAIN 9 NW CARLYLE 46.73N 104.22W
05/10/2011 M1.51 INCH WIBAUX MT TRAINED SPOTTER
STORM TOTAL AS OF 8AM TODAY. RAIN IS STILL FALLING.
BEAVER CREEK IS UP SLIGHTLY.
0805 AM HEAVY RAIN 15 SSE CULBERTSON 47.93N 104.45W
05/10/2011 M2.00 INCH RICHLAND MT TRAINED SPOTTER
RAINFALL TOTAL FROM MONDAY MORNING THROUGH 630AM TODAY.
WATER IS RUNNING TOWARDS THE CREEKS AND THE COUNTY ROADS
ARE STARTING TO RUN WITH WATER.
0808 AM HEAVY RAIN 11 N CROW ROCK 47.07N 106.03W
05/10/2011 M2.30 INCH PRAIRIE MT TRAINED SPOTTER
RAINFALL TOTAL SINCE YESTERDAY MORNING. RAIN IS CURRENTLY
FALLING.
&&
ASCHNETZPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GLASGOW MT
831 AM MDT TUE MAY 10 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0644 AM HEAVY RAIN 13 NW MCCLOUD 47.03N 105.80W
05/10/2011 E1.60 INCH PRAIRIE MT MESONET
RAINFALL TOTAL FROM 644AM YESTERDAY TO 644AM TODAY AT THE
BIG SHEEP MOUNTAIN RAWS.
0823 AM HEAVY RAIN 6 N WINNETT 47.09N 108.35W
05/10/2011 M1.75 INCH PETROLEUM MT TRAINED SPOTTER
RAINFALL TOTAL FROM SUNDAY THROUGH 7AM TODAY. BOX ELDER
CREEK HAS STARTED TO LEAVE ITS BANKS BUT REMAINS BELOW
THE BRIDGES.
&&
ASCHNETZPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
934 AM MDT TUE MAY 10 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0925 AM HEAVY RAIN 1 SE CIRCLE 47.41N 105.59W
05/10/2011 M2.10 INCH MCCONE MT TRAINED SPOTTER
MEASURED 2.10 INCHES OF RAINFALL IN THE PAST 24 HOURS.
&&
RMORGANThe national radar mosaic for the moment the first event began.
4 flood. Local standard time, as filed.
Flooding was reported on many creeks in central and southern Valley County, including Antelope, Willow and Brazil Creeks. Rainfall amounts totaled: 1.41 inches 4 southwest of Hinsdale; 1.62 inches at King Coulee Raws; 2.5 inches 5 miles south-southeast of Tampico.
Minor flooding was reported on the Big Dry Creek. Hell Creek Recreation Area measured 3.2 inches of rainfall.
Flooding was reported on the Redwater River. Wolf Point ASOS reported 1.33 inches with this storm. One mile southeast of Circle measured 2.1 inches of rain, while a spotter 20 miles north of Circle reported 3.72 inches.
Two to three inches of rain fell across the area resulting in some minor flooding of creeks and streams.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2011Every state in 2011This day in weather historyWarnings in Montana, May 2011
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: 309005, 309009, 309010, 309011.