Multicellular thunderstorms produced some strong winds that caused minor damage.
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.
Multicellular thunderstorms produced some strong winds that caused minor damage.
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 14, 1:44 PM MST, 3 hours 21 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 244 PM MDT THU MAY 14 2009 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY... GOES WATER VAPOR IMAGERY DEPICTS A BROAD SHORTWAVE TROUGH DIVING INTO THE PACIFIC NORTHWEST. AT THE SURFACE...A SURFACE LOW IS ORGANIZING OVER SOUTHERN ALBERTA/NORTH CENTRAL MONTANA...WITH A SURFACE TROUGH EXTENDING SOUTH ACROSS CENTRAL MONTANA. SCATTERED CONVECTIVE SHOWERS ARE DEVELOPING OVER NORTH CENTRAL MONTANA IN A BAND OF PVA AHEAD OF THE APPROACHING TROUGH AXIS. RADAR ECHOES FROM THE KTFX RADAR SUGGEST ENOUGH INSTABILITY HAS DEVELOPED IN THIS ZONE TO PRODUCE LIGHTNING...AND THUS THUNDER. THESE SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PROGRESS ACROSS THE CWA FROM WEST TO EAST LATE THIS AFTERNOON AND EVENING. A COLD FRONT WILL DEVELOP AS THE UPPER TROUGH MOVES TO THE LEE OF THE ROCKIES...AND PASS THROUGH NORTHEAST MONTANA LATE TONIGHT. RAIN SHOWERS WILL DIMINISH RAPIDLY AFTER MIDNIGHT BEHIND THE COLD FRONT AS DRIER AIR ADVECTS SOUTHEAST FROM THE CANADIAN PRAIRIES. 850MB WIND SPEED INCREASE TO 25-35KT BEHIND THE FRONT FRIDAY MORNING AND THEN STEADILY DECREASE TO 10KT WEST...20KT EAST...BY THE AFTERNOON. A BREEZY PERIOD IS EXPECTED DURING THE MORNING...BUT THE SURFACE WIND SHOULD RELAX DURING THE AFTERNOON. LAKE WIND ADVISORY CRITERIA WIND SPEEDS ARE POSSIBLE IN THE MORNING. HOWEVER...THE DURATION MAY NOT BE LONG ENOUGH TO SUPPORT AN ADVISORY. A SECONDARY VORTICITY MAXIMA ROTATES THROUGH THE AREA AROUND MIDDAY...BUT IT IS FAIRLY WEAK AND THE AIRMASS IS DRY...SO REMOVED POPS FOR THE DAYTIME PERIOD. SURFACE MAXIMUM TEMPERATURES WILL BE UNSEASONABLY COLD AS 850MB TEMPERATURES RANGE FROM NEAR -1C NORTHEAST...TO 4C SOUTHWEST. WARM ADVECTION COMMENCES FRIDAY NIGHT AS AN UPPER RIDGE BEGINS TO BUILD OVER THE INTERMOUNTAIN WEST. ANOTHER MID-SPRING FREEZE IS LIKELY SATURDAY MORNING BEFORE TEMPERATURES WARM INTO THE 60S AND LOW 70S SATURDAY AFTERNOON. AJZ .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY... CONFIDENCE IS HIGH IN THE EARLY PART OF THE PERIOD...WITH AN UPPER RIDGE MAKING FOR WARM AND DRY CONDITIONS INTO SUNDAY NIGHT. FOR MONDAY AND BEYOND THE FORECAST MODELS AND ENSEMBLE MEMBERS ARE HAVING A DIFFICULT TIME IN RESOLVING HOW THE UPPER RIDGE WILL BE IMPACTED BY A POLAR VORTEX LOCATED OVER HUDSON BAY AND AN APPROACHING UPPER LOW OFF THE PACIFIC. GIVEN THE CONTINUED UNCERTAINTY...HAVE LOWERED CONFIDENCE IN THE FORECAST. OPTED TO LEAVE IT LARGELY UNCHANGED FAVORING THE POLAR VORTEX PUSHING DOWN THE RIDGE BEGINNING ON MONDAY...BEGINNING A COOLING TREND. ALSO CONTINUED TO REFLECT A SLOWER TIMING ON THE IMPACT OF THE PACIFIC TROUGH FROM THE WEST GIVEN THE STRENGTH OF THE UPPER RIDGE OVER THE WESTERN UNITED STATES. GILCHRIST PREVIOUS DISCUSSION...ECMWF AND GFS BOTH BRING UPPER RIDGING TO THE AREA FOR THE WEEKEND PROVIDING DRY AND WARMER CONDITIONS WITH TEMPERATURES CLIMBING ABOVE NORMAL...WHICH HAS BEEN A FAIRLY RARE OCCURRENCE THIS SPRING. THEY BEGIN TO GO THEIR SEPARATE WAYS HOWEVER EARLY NEXT WEEK WITH THE ECMWF BEING MORE STAUNCH IN KEEPING THE RIDGE ACROSS THE WEST AS OPPOSED TO THE RAPID EXIT EAST PORTRAYED BY THE GFS. AM HAVING A HARD TIME AT PRESENT COMING TO GRIPS WITH HOW QUICKLY THE GFS WANTS TO DISPATCH THE RIDGE IN THE FACE OF ANOTHER INCOMING TROF. GFS ENSEMBLE ALL OVER THE PLACE EARLY NEXT WEEK WITH SOLUTIONS RANGING FROM TROF TO RIDGE. WILL OPT FOR THE ECMWF SOLUTION AS IT DOES SEEM A LITTLE MORE PLAUSIBLE AT PRESENT AND KEEP THE EFFECTS OF THE UPPER RIDGE AROUND A BIT LONGER THRU EARLY NEXT WEEK BEFORE BRINGING A WEAKER SYSTEM ACROSS AROUND THE MIDDLE OF NEXT WEEK WITH A CHANCE FOR SHOWERS. APPEARS THAT A COLD FRONT MAY BACKDOOR ITS WAY INTO THE AREA MONDAY NIGHT FROM THE NORTHEAST AND ALSO PROVIDE A CHANCE FOR SOME SHOWERS AS IT DOES. CONDITIONS DRY ONCE AGAIN FOR THE END OF NEXT WEEK IN THE WAKE OF THE MIDWEEK SYSTEM. && .AVIATION... VFR CONDITIONS WILL PERSIST THIS EVENING UNDER A SCT-BKN MID LEVEL DECK. SCATTERED SHOWERS HOWEVER WILL BE AROUND ALONG WITH CUMULUS AROUND 6-8K FEET AGL. AN ISOLATED THUNDERSTORM REMAINS A THREAT THIS EVENING...AND COULD BRIEFLY MAKE FOR MVFR CONDITIONS AT ANY OF THE TERMINALS. WEST TO SOUTHWEST WINDS WILL CONTINUE AT 10 TO 20 KTS THROUGH THE EVENING. WINDS WILL THEN TURN TO THE NORTHWEST EARLY FRIDAY MORNING WITH THE PASSAGE OF A COLD FRONT...AND INCREASE TO 15 TO 25 KTS BY SUNUP. SHOWER ACTIVITY WILL TAPER SOME...BUT CLOUDS WILL LOWER TO NEAR MVFR BEHIND THE FRONT. MVFR CONDITIONS WILL PERSIST THRU FRIDAY MORNING BEFORE CEILINGS RISE TO VFR AND WINDS DECREASE TO 10 TO 20 KTS AROUND NOON. GILCHRIST && .CLIMATE... THE MEASURABLE SNOW IN GLASGOW YESTERDAY MAY 13TH WAS 1.5 INCHES AT THE AIRPORT. ONLY 5 TIMES IN THE PAST HAS THERE BEEN MEASURABLE SNOWFALL ANY LATER IN THE SEASON...THE LAST TIME BEING IN 2002. SEASON SNOWFALL OF 52.6 INCHES RANKS THE 2008-09 SEASON AS THE 4TH SNOWIEST ON RECORD. SIMONSEN && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 859 PM MDT WED MAY 13 2009 MTZ016>027-059>062-140400- 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- 859 PM MDT WED MAY 13 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The Glasgow radar (KGGW), 47 km away, was scanning. The volume nearest the first event began at 00:03 UTC.
1 thunderstorm wind. Local standard time, as filed.
Strong winds estimated at 60 mph caused tree limbs roughly four feet by two inch diameter to fall to the ground. Pea sized hail was also reported.
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: 159105.