An upper trough caused some multicellular thundershowers.
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.
An upper trough caused some multicellular thundershowers.
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, 7:36 PM MST, 19 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 836 PM MDT TUE MAY 5 2009 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH THURSDAY... PREFRONTAL SURFACE TROF ATTENDED BY A DISTURBANCE ALOFT TRIGGERED A ROUND OF SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. CONVECTION NOW MORE OR LESS ON ITS LAST LEGS AS IT APPROACHES THE NORTH DAKOTA BORDER. DID HAVE SOME DECENT WIND COME ACROSS MUCH OF THE AREA WITH A BROKEN LINE OF STORMS EARLIER THAT HAS SINCE BECOME EXTREMELY RAGGED AND LOST DEFINITION. WILL UPDATE TO REFLECT THE CURRENT STATE OF PRECIPITATION AND WHAT CAN NOW BE EXPECTED OVERNIGHT WHICH IS A CLEARING SKY AND A WESTERLY BREEZE AS PRECIPITATION WILL BE OVER IN THE EAST BEFORE MIDNIGHT WITH NOTHING FURTHER EXPECTED TONIGHT. MADE A FEW OTHER MINOR MODIFICATIONS TO TEMPERATURES AND WIND...BUT NOTHING MAJOR THERE. PREVIOUS DISCUSSION... A PASSING SHORTWAVE IS CURRENTLY TRIGGERING SCATTERED SHOWERS ACROSS THE CENTRAL PART OF THE TREASURE STATE. SAID FEATURE WAS SPUN OFF A PARENT LOW WHICH IS CURRENTLY OFF THE COAST OF BRITISH COLUMBIA. SHOWER AND THUNDERSTORM ACTIVITY WILL MOVE INTO THE EASTERN ZONES THIS EVENING AS THE ASSOCIATED SURFACE FRONT PUSHES THROUGH. WEDNESDAY AND WEDNESDAY NIGHT WILL BE MAINLY DRY AS WEAK RIDGING BUILDS IN BEHIND TONIGHTS SYSTEM...BUT WINDY. AN UPPER LOW CENTERED OVER SOUTHERN SASKATCHEWAN WILL BE THE DOMINANT WEATHER FEATURE...AND COULD MAKE FOR A FEW SHOWERS OVER DANIELS AND SHERIDAN COUNTIES IN THE AFTERNOON AND EVENING. GUSTY WESTERLY WINDS WILL BLOW IN RESPONSE TO THE SAME LOW PRESSURE SYSTEM. A LAKE WIND ADVISORY LOOKS LIKELY AT THIS TIME. THURSDAY ANOTHER SHORTWAVE FEATURE WILL BE EJECTED THROUGH THE NORTHERN ROCKIES. GOOD INSTABILITY EXISTS AHEAD OF AND WITH THIS FEATURE AND SCATTERED SHOWERS AND THUNDERSTORMS WILL BE A RESULT IN THE AFTERNOON. GILCHRIST .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY... AN ENERGETIC UPPER LOW...SHOWING SIGNS OF CLOSING OFF...SCOOTS OVER MONTANA THURSDAY NIGHT AND FRIDAY. MODELS ARE INDICATING QPF AMOUNTS OF 0.15 TO 0.30 INCH OF WATER FOR FRIDAY. CHANCE POPS LOOK GOOD FOR DAY 4. UPPER FLOW THEN TRENDS MORE ZONAL FOR SATURDAY AS WEAK DISTURBANCES TREK THROUGH SOUTHERN SASKATCHEWAN. MODELS AGREE WITH ANOTHER SHORTWAVE TROUGH SUNDAY MOVING INTO THE PACNW. THIS WILL EJECT ADDITIONAL IMPULSES THROUGH THE LOCAL REGION. MONDAY THE TROUGH BECOMES MORE ENERGETIC AS IT APPROACHES MT. BUT MODELS DIFFER IN LATITUDE BY A FEW HUNDRED MILES. THE DISTURBANCE COULD SWING SOUTH...ACCORDING TO GFS...OR OVER US ACCORDING TO EC AND DGEX. MODELS ALL AGREE WITH ANOTHER...MUCH STRONGER...SYSTEM MOVING INTO THE NW MONDAY NIGHT. BUT TIMING AND LOCATION VARY WIDELY AMONG MODELS. OVERALL THE PATTERN WILL CONTINUE WET AND SHOWERY WITH TEMPERATURES FAIRLY CLOSE TO NORMAL. OTHER THAN ADJUSTING POPS HERE THAN THERE IN THE FIRST HALF OF THE PERIOD...FEW CHANGES NEEDED TO ONGOING FORECAST. SCT PREVIOUS DISCUSSION... MODELS ARE IN DECENT AGREEMENT WITH THE EXTENDED FORECAST. A SHORTWAVE TROUGH PASSING THOUGH NORTHEAST MONTANA AROUND 12Z FRIDAY WILL BRING A CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY. THEN...WEST TO WNW FLOW ALOFT PREVAILS FOR MOST OF THE WEEKEND WITH WEAK SHORTWAVES PASSING THROUGH THE AREA WHICH WILL PROVIDE A SLIGHT CHANCE OF SHOWERS. TEMPERATURES FOR MOST OF THE PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL. GOING INTO NEXT WEEK...GFS AND ECMWF ARE IN BETTER AGREEMENT ON HOW THEY BRING A CLOSED UPPER LOW INLAND FROM THE PACIFIC. THE TWO MODELS AGREE ON A MOIST SHORTWAVE SUNDAY NIGHT AND MONDAY AHEAD OF THE MAIN LOW WHICH LOOKS LIKE IT WILL MOVE THROUGH EASTERN MONTANA ON TUESDAY. && .AVIATION... SHOWERS AND THUNDERSTORMS WILL QUICKLY EXIT THE AREA THIS EVENING ALLOWING VFR CONDITIONS AND A LIGHT WESTERLY WIND OF 5-10KT TO PREVAIL OVERNIGHT. BY MID MORNING WEDNESDAY...A STRONG MID-LEVEL 40KT-50KT JET WILL BEGIN MIXING TOWARDS THE SURFACE TO REINFORCE THE WESTERLY WINDS. EXPECT 15G25KT-25G35KTS SURFACE WINDS BY NOON...CONTINUING THROUGH THE AFTERNOON. SCT/AJZ && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && WEATHER.GOV/GLASGOW
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
610 PM MDT TUE MAY 05 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0538 PM TSTM WND GST GLASGOW 48.20N 106.64W
05/05/2009 M54 MPH VALLEY MT OFFICIAL NWS OBS
SUSTAINED 45 MPH WITH GUST TO 54 MPH
&&
MATTMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
623 PM MDT TUE MAY 05 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0540 PM TSTM WND GST 4 N GLASGOW 48.25N 106.64W
05/05/2009 E53 MPH VALLEY MT NWS EMPLOYEE
SUSTAINED 40 MPH WITH GUST TO 53 MPH
&&
MATTMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
648 PM MDT TUE MAY 05 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0628 PM TSTM WND GST 9 SSW LUSTRE 48.26N 105.93W
05/05/2009 M52 MPH VALLEY MT TRAINED SPOTTER
&&
MATTMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
801 PM MDT TUE MAY 05 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0654 PM TSTM WND GST WOLF POINT 48.09N 105.64W
05/05/2009 M49 MPH ROOSEVELT MT ASOS
&&
AJZPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
803 PM MDT TUE MAY 05 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0705 PM TSTM WND GST CIRCLE 47.42N 105.60W
05/05/2009 M54 MPH MCCONE MT MESONET
&&
AJZPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
806 PM MDT TUE MAY 05 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0740 PM TSTM WND GST 18 NW ENID 47.88N 105.05W
05/05/2009 M54 MPH RICHLAND MT TRAINED SPOTTER
&&
AJZThe Glasgow radar (KGGW), 191 km away, was scanning. The volume nearest the first event began at 02:55 UTC.
1 thunderstorm wind. Local standard time, as filed.
A weak thunderstorm collapsed over Sidney. The only damage reported was an old roof was blown off of an old building near the sugar plant.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2009Every state in 2009This day in weather historyWarnings in Montana, May 2009
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: 158080.