A very strong storm system over Colorado resulted in high winds across portions of the far Eastern Plains during a 48 hour period from May 21st through the morning of the 22nd.
Every event with a place to put it; 5 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 BYZ wrote it up.
A very strong storm system over Colorado resulted in high winds across portions of the far Eastern Plains during a 48 hour period from May 21st through the morning of the 22nd.
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 Billings, MT wrote its last area forecast discussion before the first event at May 21, 8:26 AM MST, 2 hours 14 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
926 AM MDT WED MAY 21 2008
.SHORT TERM...VALID FOR TDY AND THU...
FIRST WAVE OF ACTIVITY PUSHING ACROSS THE AREA THIS MORNING. NAM
IS HANDLING THIS ACTIVITY VERY WELL. LOOKS LIKE THERE SHOULD BE A
SLOWER PERIOD AFTER THIS FIRST WAVE BEFORE STRONGER ACTIVITY AGAIN
THIS EVENING. HAVE TRIED TO TREND THIS IN POP AND WEATHER GRIDS IN
CENTRAL ZONES WITH CATEGORICAL POPS THIS MORNING AND LESSER BUT
STILL HIGH POPS THIS AFTERNOON. OVER WESTERN ZONES...LOOKS LIKE
WAVE AFTER WAVE OF MOISTURE TODAY. ACTUAL HIGH TEMPERATURES HAVE
ALREADY OCCURRED SO TWEAKED TEMPERATURES DOWN TO NEAR CURRENT
VALUES IN WEST AND CENTRAL IN THE 50S AND LOWER A TAD IN THE EAST
AHEAD OF THE FRONT.
THINGS STILL LOOKING GOOD FOR A EXTENDED RAIN EVENT THROUGH AT
LEAST FRIDAY. BETTER AGREEMENT NOT IN MODELS THAT THERE SHOULD BE
DECREASE IN RISK OF HEAVY MOISTURE AFTER FRIDAY AS ENERGY
REORGANZIED TO THE NORTH...BUT WILL OF COURSE LOOK CLOSER AT THIS
FOR AFTERNOON UPDATE. RASCH
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MODELS IN PRETTY GOOD AGREEMENT IN THE EXTENDED FORECAST PERIOD
AND THUS HAVE MADE VERY LITTLE CHANGES. OVERALL PATTERN REMAINS
UNSETTLED THROUGH THE END OF THE WEEK WITH THE WEEKEND AND EARLY
NEXT STILL A BIT UNCERTAIN.
LARGE UPPER LEVEL LOW CONTINUES TO SPIN AND BRING IN PLENTY OF
MOISTURE INTO THE FORECAST AREA ON FRIDAY. HAVE BUMPED UP POPS A
LITTLE MORE FOR THIS PERIOD AND THINK THE BEST CHANCE WILL BE
DURING THE MORNING HOURS. A SLIGHT SOUTHWEST FLOW SETS UP BEYOND
FRIDAY AS SEVERAL SHORTWAVES MOVE OVER THE AREA AND CONTINUED AT
LEAST A SLIGHT CHANCE OF PRECIP FOR EACH DAY. WITH THIS DYNAMIC
OF A SYSTEM WILL CONTINUE THE MENTION OF THUNDERSTORMS FOR MOST
DAYS.
TEMPERATURES DO LOOK A LITTLE WARMER FOR FRIDAY AND CONTINUE A
GRADUAL WARM UP INTO NEXT WEEK AS THE MAIN UPPER LOW BEGINS TO
MOVE OUT OF THE AREA AND A SOUTHWEST FLOW SETS UP OVER THE AREA.
ONLY MADE SOME MINOR TWEAKS TO THE TEMPERATURES AS THEY LOOKED ON
TRACK FOR THIS GRADUAL WARM UP. SOLUM
&&
.AVIATION...
WEST OF A ROUNDUP TO SHERIDAN LINE...NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS EXPECTED THROUGH THE DAY. MVFR CONDITIONS EXPECTED
WITH HEAVIER SHOWERS/THUNDERSTORMS...OTHERWISE VFR CEILINGS
EXPECTED. MOUNTAIN OBSCURATION EXPECTED THROUGH FRIDAY MORNING.
GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH LATE TONIGHT.
EAST OF A ROUNDUP TO SHERIDAN LINE...ISOLATED SHOWERS THIS
MORNING...SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON. VFR
CEILINGS EXPECTED...WITH OCCASIONAL MVFR CONDITIONS IN HEAVIER
PRECIPITATION. SOUTHEAST WINDS GUSTING TO NEAR 50 MPH EXPECTED
OVER EASTERN AREAS TODAY...SHIFTING TO THE NORTHWEST TONIGHT.
CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 058 040/051 043/062 044/065 045/067 044/069 045/072
8/T +8/T 77/T 53/T 32/T 22/T 22/T
LVM 048 037/046 037/058 039/059 039/062 038/066 041/066
9/T +8/T 67/T 54/T 33/T 33/T 33/T
HDN 062 042/054 045/066 046/068 046/068 046/071 045/074
4/T +8/T 77/T 53/T 32/T 22/T 22/T
MLS 067 046/060 048/065 048/070 047/069 046/071 047/070
2/T 87/T 67/T 53/T 32/T 22/T 22/T
4BQ 071 045/059 047/066 048/070 046/067 045/070 045/071
2/T 97/T 77/T 53/T 32/T 22/T 22/T
BHK 066 045/063 046/063 050/069 048/066 044/069 045/067
2/T 77/T 67/T 53/T 32/T 22/T 22/T
SHR 063 040/056 042/064 043/064 043/064 042/065 042/069
4/T +8/T 77/T 54/T 33/T 32/T 32/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FLOOD WATCH IN EFFECT FROM 6 PM MDT THIS EVENING THROUGH
SUNDAY AFTERNOON FOR ZONES 28-34-38>42-56-57-63>68.
WY...FLOOD WATCH IN EFFECT FROM 6 PM MDT THIS EVENING THROUGH
SUNDAY AFTERNOON FOR ZONES 98-99.
&&
WEATHER.GOV/BILLINGSHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BILLINGS MT 536 AM MDT WED MAY 21 2008 MTZ028>042-056>058-063>068-WYZ098-099-221145- SOUTHERN WHEATLAND-MUSSELSHELL-TREASURE-NORTHERN ROSEBUD-CUSTER- FALLON-NORTHERN STILLWATER-YELLOWSTONE-POWDER RIVER-CARTER- SOUTHERN BIG HORN-EASTERN CARBON-NORTHERN PARK- NORTHERN SWEET GRASS-GOLDEN VALLEY-RED LODGE FOOTHILLS- NORTHERN BIG HORN-SOUTHERN ROSEBUD-JUDITH GAP-PARADISE VALLEY- LIVINGSTON AREA-BEARTOOTH FOOTHILLS-ABSAROKA/BEARTOOTH MOUNTAINS- CRAZY MOUNTAINS-NORTHEAST BIG HORN MOUNTAINS-SHERIDAN FOOTHILLS- 536 AM MDT WED MAY 21 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...SOUTH CENTRAL MONTANA...SOUTHEAST MONTANA AND NORTH CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SNOWMELT CONTINUES TO CAUSE AREA STREAMS AND RIVERS TO RUN HIGH WITH A FLOOD WARNING CONTINUING FOR THE YELLOWSTONE RIVER AT LIVINGSTON. WHILE COOLER TEMPERATURES ARE EXPECTED TO MOVE INTO THE AREA WHICH WILL SLOW DOWN THE SNOWMELT...A STORM SYSTEM WILL BRING WIDESPREAD PRECIPITATION BY LATE TODAY. THIS PRECIPITATION WILL BE HEAVY AT TIMES AND COULD POSSIBLY CAUSE INCREASED LEVELS ON RIVERS AND STREAMS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE STORM SYSTEM WILL CONTINUE TO IMPACT THE AREA THROUGH FRIDAY AND SATURDAY WITH PERIODS OF HEAVY RAIN POSSIBLE. EVEN THOUGH THE SNOWMELT WILL BEGIN TO SLOW DOWN AREA STREAMS AND RIVERS WILL REMAIN HIGH WITH THE EXPECTED RAINFALL CAUSING MORE WIDESPREAD IMPACTS. A FLOOD WATCH HAS BEEN ISSUED FOR PORTIONS OF SOUTH CENTRAL MONTANA FOR THIS STORMS POTENTIAL. FOLLOW FUTURE FORECASTS AND STATEMENTS AS THIS SITUATION EVOLVES OVER THE COMING DAYS. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The national radar mosaic for the moment the first event began.
5 high wind. Local standard time, as filed.
Sustained winds of 40 mph were reported across Carter County.
Sustained winds of 43 mph were reported in Alzada.
Sustained winds of 46 mph were reported 9 SSW of Willard. At 220 pm, sustained winds of 44 mph with gusts to 58 mph were reported at the Baker ASOS.
Sustained winds of 40 mph were reported across southeast Powder River County. Sustained winds of 50 mph were reported in Biddle.
Sustained winds of 40 mph were reported at the Government Hill DOT.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2008Every state in 2008This day in weather historyWarnings in Montana, May 2008
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: 99560, 99582, 99589, 99581, 99579.