Strong Bora winds developed along the Front Range following the passage of a storm system. Peak wind gusts included: 87 mph at the National Wind Technology Center; 82 mph, 6 miles northwest of Boulder; 80 mph, 7 miles northwest of Berthoud; 72 mph at Front Range Airport in Broomfield; 71 mph at Longmont; 68 mph at Berthoud and 64 mph, 4 miles west of Lakewood.
Every event with a place to put it; 4 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 BOU wrote it up.
Strong Bora winds developed along the Front Range following the passage of a storm system. Peak wind gusts included: 87 mph at the National Wind Technology Center; 82 mph, 6 miles northwest of Boulder; 80 mph, 7 miles northwest of Berthoud; 72 mph at Front Range Airport in Broomfield; 71 mph at Longmont; 68 mph at Berthoud and 64 mph, 4 miles west of Lakewood.
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 Denver/Boulder, CO wrote its last area forecast discussion before the first event at Mar 22, 2:30 PM MST, 1 hour 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 330 PM MDT TUE MAR 22 2011 .SHORT TERM...GUSTY WINDS HAVE MIXED ACROSS MUCH OF PLAINS AND FOOTHILLS AS PREVIOUSLY ADVERTISED. SPEEDS ALONG FOOTHILLS AND ADJACENT PLAINS HAVE APPROACHED THE SUSTAINED CRITERIA FOR HIGH WINDS. LATEST FORECAST SOUNDINGS INDICATE CURRENT CONDITIONS TO PERSIST INTO THE EVENING. DON'T SEE GUSTS TO 75 MPH DUE TO LACK OF DECENT STABLE LAYER. WILL CONTINUE WITH HIGH WIND WARNING FOR FOOTHILLS AND ADJACENT PLAINS THROUGH 04Z. WINDS STILL PROGGED TO DECREASE AFTER 04Z SO ANY THREAT FOR HIGH WINDS SHOULD END AT THAT TIME. AS FOR RED FLAG WARNINGS...WINDS AND RH CERTAINLY HITTING AND EVEN EXCEEDING CRITERIA. MODELS INDICATE WIND TO BE ON THE DECREASE WITH HUMIDITY INCREASING. HUMIDITY ALONG FOOTHILLS MAY BE A BIT SLOWER TO RECOVER INITIALLY. ACROSS MOUNTAINS...CROSS SECTIONS SHOW MOISTURE ON THE DECREASE THIS EVENING. STILL DECENT OROGRAPHICS TO KEEP A CHANCE OF SNOW FOR THIS EVENING...WITH A DECREASE AFTER MIDNIGHT. ON WEDNESDAY...MODELS CONTINUE TO ADVERTISE AN UPPER LEVEL RIDGE IN PLACE. CROSS SECTIONS SHOW GUSTY WINDS CONFINED TO HIGHER MOUNTAINS...WITH MUCH LESS WIND FOR FOOTHILLS AND PLAINS. HUMIDITIES WILL AGAIN BE LOW ALONG THE FOOTHILLS AND PLAINS WITH WARMER TEMPERATURES AND DRY CONDITIONS EXPECTED. THERE WILL STILL BE A NORTHWEST SURFACE GRADIENT ACROSS THE PLAINS...AND WITH ENOUGH MIXING SHOULD SEE SOME NORTHWESTERLIES DURING THE AFTERNOON. SPEED TO STAY BELOW RED FLAG CRITERIA EVEN THOUGH HUMIDITY WILL BE LOW. .LONG TERM...PROGRESSIVE WEATHER PATTERN STILL LOOKS LIKE IT WILL PREVAIL THROUGH THE WEEKEND BEFORE A LITTLE AMPLIFICATION EARLY NEXT WEEK. THROUGH THE END OF THE WEEK...ZONAL FLOW ALOFT WILL BRING MILD AND DRY CONDITIONS TO THE FORECAST AREA. THE ECMWF AND GFS BOTH SHOW FLAT RIDGING AND LOWER RELATIVE HUMDITY LEVELS. A FEW MOUNTAIN SNOW SHOWERS MAY LINGER. SURFACE PRESSURE PATTERN ALSO SHOW A GOOD LEE TROUGH OVER THE EASTERN PLAINS. OVER THE WEEKEND...MORE UNSETTLED WEATHER WILL SPREAD FROM THE MOUNTAINS OUT ACROSS THE PLAINS AS UPPER TROUGHINESS WORKS ITS WAY ACROSS THE STATE. THE UPPER TROUGH IS WEAKLY ORGANIZED SO IT IS HARD TO FOCUS ON ANY SINGLE PERIOD THAT WILL RECEIVE THE MOST PRECIPITATION. LOW LEVEL FLOW WILL HAVE AN EASTERLY COMPONENT THROUGH THE WEEKEND WHICH WILL MAKE IT POSSIBLE FOR MOISTURE FROM THE CENTRAL PLAINS TO ADVECT INTO THE AREA...ESPECIALLY ON SUNDAY WHEN GULF MOISTURE MIGHT BE ARRIVING ON SOUTHEASTERLY FLOW. SUNDAY MORNING/S PATTERN ACTUALLY HAS A NICE EARLY SPRING APPEARANCE TO IT. THIS WILL PROBABLY MAKE SUNDAY AFTERNOON AND EVENING THE WETTEST PART OF THE WEEKEND. EARLY NEXT WEEK...IT APPEARS A BIT MORE RIDGING WILL BE BUILDING OVER THE GREAT BASIN AND WESTERN SLOPE WHICH WILL DRY THINGS OUT AND ALLOW TEMPERATURES TO WARM UP. TEMPERATURES THROUGH THE REST OF THE FORECAST PERIOD SHOULD BE AROUND TO SLIGHTLY ABOVE NORMAL DUE TO THE ZONAL NATURE OF THE FLOW PATTERN. && .AVIATION...STRONG WEST TO NORTHWEST WINDS IN THE 25 TO 35 KT RANGE STILL EXPECTED TO GRADUALLY DECREASE AFTER 02Z AS GRADIENT WEAKENS. MODELS STILL INDICATING WINDS TO BECOME SOUTHWEST AROUND 12Z BY 04Z AS DRAINAGE PATTERN DEVELOPS. THIS LOOKS REASONABLE AS AIRMASS COOLS AND GRADIENT WEAKENS. GUSTY WINDS WILL BE SLOW TO DECREASE AT KBJC. BY 18Z...WINDS TO SWITCH TO THE NORTHWEST AS WINDS ALOFT MIX TO THE SURFACE. SPEEDS TO BE MUCH LIGHTER THAT TODAY...PERHAPS IN THE 10-20 KT RANGE. VFR CONDITIONS TO PREVAIL THROUGH WEDNESDAY. && .BOU WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING IN EFFECT THROUGH 10 PM MDT FOR FIRE WEATHER ZONES 214>216..238 AND 239. RED FLAG WARNING IN EFFECT UNTIL 8 PM MDT FOR FIRE WEATHER ZONES 240>251. HIGH WIND WARNING IN EFFECT UNTIL 10 PM FOR THE FRONT RANGE FOOTHILLS AND URBAN CORRIDOR...ZONES 35..36..38 AND 39. && SHORT TERM...D-L LONG TERM....KDRBY AVIATION...D-L
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1113 AM MDT TUE MAR 22 2011 COZ030>051-231200- JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000 FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/ NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/ SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/ EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES- NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS COUNTY- 1113 AM MDT TUE MAR 22 2011 ...HIGH WIND WARNING AND RED FLAG WARNINGS IN EFFECT ACROSS NORTHEAST COLORADO THIS AFTERNOON AND EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT STRONG WEST TO NORTHWEST WINDS ALOFT ARE DEVELOPING OVER THE STATE TODAY WHICH WILL BRING GUSTY WINDS TO THE EASTERN SLOPES OF THE MOUNTAINS...THE FOOTHILLS AND ADJACENT PLAINS. WINDS WILL BE STRONGEST THIS AFTERNOON AND EARLY EVENING IN AND NEAR THE FRONT RANGE FOOTHILLS AND ALONG THE CHEYENNE RIDGE. ALTHOUGH IT WILL BE COOLER TODAY...THE STRONG WINDS AND CONTINUED LOW RELATIVE HUMIDITIES THIS AFTERNOON WILL KEEP THE FIRE DANGER ELEVATED. AS A RESULT...A RED FLAG WARNING IS IN EFFECT FOR MOST OF THE REGION THIS AFTERNOON AND EVENING. A HIGH WIND WARNING IS ALSO IN EFFECT OVER THE FOOTHILLS AND THE URBAN CORRIDOR. WEST WINDS OF 45 TO 55 MPH WITH GUSTS UP TO 65 MPH WILL BE POSSIBLE. SOME LIGHT SNOW IS EXPECTED IN THE MOUNTAINS MAINLY ALONG WEST FACING SLOPES TODAY... DIMINISHING OVERNIGHT. THE STRONG WINDS OVER THE REGION WILL DECREASE LATE THIS EVENING...LINGERING LONGEST IN THE FOOTHILLS THIS EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY A SERIES OF PACIFIC STORM SYSTEMS WILL MOVE ACROSS THE REGION LATE THIS WEEK AND OVER THE WEEKEND. THIS WILL BRING PERIODS OF SNOW TO THE MOUNTAINS FROM THURSDAY THROUGH THE WEEKEND. SNOW ACCUMULATIONS SHOULD REMAIN LIGHT AS THE WEATHER SYSTEMS MOVE ACROSS THE REGION QUICKLY. THE CHANCE FOR RAIN OR SNOW WILL SPREAD ONTO THE PLAINS LATE FRIDAY AND CONTINUE THROUGH THE WEEKEND. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. D-L/DANKERS
The national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2011Every state in 2011This day in weather historyWarnings in Colorado, March 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: 287584, 287585, 287589, 287591.