High winds developed along the Front Range during the early morning hours. Peak wind gusts included: 92 mph, 7 miles northwest of Berthoud; 75 mph, 2 miles west of Castle Rock; and 65 mph, 2 miles west of Elbert.
Every event with a place to put it; 2 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.
High winds developed along the Front Range during the early morning hours. Peak wind gusts included: 92 mph, 7 miles northwest of Berthoud; 75 mph, 2 miles west of Castle Rock; and 65 mph, 2 miles west of Elbert.
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 Apr 2, 8:58 PM MST, 4 hours 7 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 958 PM MDT SAT APR 2 2011 .UPDATE... && .SHORT TERM...STILL SOME CONCERN OVER HIGH WIND POTENTIAL IN AND NEAR THE FOOTHILLS LATER TONIGHT. UPDATED ZONES FOR STRONGER WINDS OVER THESE AREAS WITH GUSTS UP TO 70 MPH POSSIBLE. CROSS SECTIONS SHOWING 50-70KT OF CROSS BARRIER FLOW BY 09Z WHICH IS AWFUL STRONG. SHEAR PROFILE LOOKS GOOD BUT STABILITY IS MARGINAL AND UPSTREAM UPWARD FORCING WOULD KEEP THE STRONGEST WINDS FROM SURFACING. HAD OPTED EARLIER TO HANDLE THIS SITUATION WITH AN EXTENSION OF THE RED FLAG WARNING FOR THE FOOTHILLS...PALMER DIVIDE AND PARK COUNTY. STILL MAY SEE SOME GUSTS UP AROUND 70 MPH. THE NAM IS SURE AMBITIOUS WITH POTENTIAL SNOWFALL OVER THE FRONT RANGE BY LATE AFTN/EVENING WITH ACCUM FROM 4-8 INCHES FROM BOULDER SOUTH THROUGH DOUGLAS COUNTY. MAY NEED SOME HILITES CONSIDERING THE INSTABILITY AND JET DYNAMICS...BUT WILL LET THE MID SHIFT MAKE THE CALL BASED ON CURRENT TRENDS. .AVIATION...TERMINAL FORECASTS GENERALLY ON TRACK...BUT WITH THE COLD AIR COMING IN MORE QUICKLY THE CHANGE OVER TO SNOW MAY BE QUICKER THAN CURRENTLY ADVERTISED. THIS MAY OCCUR BY MID- LATE AFTERNOON WITH A FEW HOURS OF HEAVY SNOW POSSIBLE THROUGH THE EVENING HOURS. WILL ADJUST THE 06Z TAF'S ACCORDINGLY. && .PREV DISCUSSION... /ISSUED 740 PM MDT SAT APR 2 2011/ UPDATE... SHORT TERM...MAIN CONCERN THIS EVENING IS WHAT TO DO WITH CURRENT RED FLAG WARNINGS WHICH WILL EXPIRE AT 8 PM LOCAL. GIVEN CROSS SECTIONS SHOWING 50-60KT CROSS BARRIER FLOW INCREASING OVERNIGHT...WILL NEED TO KEEP THE RED FLAG WARNINGS FOR THE EAST SLOPES...PARK COUNTY AND PORTIONS OF THE PALMER DIVIDE. EXPECT WINDS TO DIMINISH A BIT THIS EVENING BUT INCREASE AGAIN TOWARDS MIDNIGHT AND CONTINUE THROUGH MIDDAY SUNDAY WITH POOR RH RECOVERY. WINDS HAVE ALREADY DIMINISHED OVER THE FAR NORTHEAST PLAINS. URBAN CORRIDOR IS MORE IFFY WITH STILL SOME GUSTY WINDS AND LOW RH. WOULD EXPECT SOME DECOUPLE HERE IN THE NEXT HOUR SO WILL LET THOSE EXPIRE AS WELL. UPDATE WILL SHOW NEW RED FLAG WARNING EXTENSION FOR FIRE WX ZONES 215..216..214..241. NO OTHER CHANGES FOR NOW. PREV DISCUSSION... /ISSUED 335 PM MDT SAT APR 2 2011/ SHORT TERM...DRY SOUTHWEST FLOW ALOFT CURRENTLY ACROSS COLORADO AS UPPER LEVEL TROUGH MOVES INTO THE GREAT BASING. GUSTY SOUTHWEST WINDS HAVE FINALLY DEVELOPED ACROSS PLAINS AND FOOTHILLS...WITH HUMIDITY IN THE SINGLE DIGITS AND LOW TEENS. RED FLAG WARNING HAS CERTAINLY VERIFIED. MODELS SHOW WINDS DECREASING SLIGHTLY ACROSS PLAINS AND FOOTHILLS AFTER 02Z WITH SLIGHTLY HIGHER HUMIDITY. WILL KEEP RED FLAG WARNING GOING INTO THE EVENING. WITH THE DECREASE IN WINDS PROGGED BY MODELS...WILL NOT EXTEND THE WARNING BEYOND 02Z. CROSS MOUNTAIN FLOW PROGGED TO INCREASE BY MIDNIGHT WITH 50 KTS AROUND MOUNTAIN TOP. MODEL CROSS SECTIONS SHOW LITTLE IN THE WAY OF ANY MOUNTAIN TOP STABLE LAYER...SO NOT EXPECTING WINDS REACHING HIGH WIND CRITERIA. MOISTURE TO INCREASE ACROSS AREA DURING THE EVENING....WITH THE BULK OF THE MOISTURE AFTER 06Z. SHOULD SEE SNOW DEVELOP ACROSS THE MOUNTAINS AFTER 06Z AS QG ASCENT INCREASES AHEAD OF TROUGH. DECENT COLD AIR ADVECTION ARRIVES INTO MOUNTAINS AS UPPER LEVEL TROUGH MOVES INTO COLORADO. WITH IMPROVING OROGRAPHICS AS WELL AS INCREASING QG ASCENT...WHICH IS PROGGED TO CONTINUE THROUGH THE DAY SUNDAY. WITH LONG TERM FORECASTER'S INPUT...THE WATCH FOR ZONE 31 WILL BE UPGRADED TO A WINTER STORM WARNING FOR HEAVY SNOW. AND A A WINTER WEATHER ADVISORY FOR SNOW WILL BE ISSUED FOR ZONES 33 AND 34. ALL THESE HILITES WILL BEGIN AT 3AM SUNDAY...CONTINUING INTO SUNDAY NIGHT...SEE BELOW. WILL GO SNOW AMOUNTS FOR THE ENTIRE WARNING PERIOD OF 10 TO 18 INCHES...WITH 7 TO 12 INCHES FOR THE ADVISORY. FOR THE PLAINS...MODELS NOW HAVE SIMILAR SOLUTIONS IN TIMING OF THE FRONT...MOVING INTO NORTHERN PORTION OF THE PLAINS AROUND 15Z...18Z IN DENVER AREA...AND 00Z ACROSS SOUTHERN SECTIONS OF THE CFWA. LOW LEVEL MOISTURE INCREASES BEHIND FRONT WITH UPSLOPE FLOW DEVELOPING BY 00Z. DECIDED TO GO LIKELY POPS FOR MUCH OF THE PLAINS AFTER 18Z WITH CHANCE POPS ALONG PALMER DIVIDE. TEMPERATURES WILL BE CRITICAL FOR EITHER RAIN AND/OR SNOW. FOR NOW WILL GO WITH MOSTLY RAIN FOR MUCH OF THE AFTERNOON...WITH A MIXTURE OF RAIN AND SNOW BY 21Z. WILL KEEP ANY ACCUMULATION ALONG CHEYENN RIDGE. WILL NEED TO WATCH THE TEMPS BEHIND THE FRONT...IF THEY END UP COOLER...THEN THE CHANCES FOR SNOW WILL BE GREATER WITH POSSIBLE ACCUMULATIONS. LASTLY...SOME CONCERS FOR RED FLAG CONDITIONS AHEAD OF THE FRONT ALONG THE PALMER DIVIDE. AT THIS TIME...FEEL THE HUMIDITY WILL BE HIGH ENOUGH TO PRECLUDE ANY RED FLAG WARNING. LONG TERM...MODELS HAVE THE UPPER TROUGH AXIS PUSH ACROSS THE CWA SUNDAY NIGHT...WITH STRONG NORTH-NORTHWESTERLY FLOW ALOFT ON MONDAY. THE FLOW IS NORTHWESTERLY AND DECREASING ON MONDAY NIGHT AS AN UPPER RIDGE MOVES INTO THE FORECAST AREA. ZONAL FLOW ALOFT IS PROGGED ON TUESDAY. BY TUESDAY NIGHT WEST-SOUTHWESTERLY FLOW ALOFT IS EXPECTED. THE QG VERTICAL VELOCITY FIELDS HAVE FAIRLY DECENT UPWARD SYNOPTIC SCALE ENERGY PROGGED SUNDAY EVENING...THEN DOWNWARD MOTION MOVES IN AFTER MIDNIGHT. THE DOWNWARD VERTICAL VELOCITY IS PROGGED TO CONTINUE MONDAY...BECOMING VERY WEAK MONDAY NIGHT. BENIGN ENERGY IS PROGGED FOR THE CWA TUESDAY AND TUESDAY NIGHT IN THE SYNOPTIC SCALE. THE BOUNDARY LAYER FLOW STAYS UPSLOPE NORTHERLY EARLY SUNDAY NIGHT...THEN BECOMES NORTHWESTERLY AFTER 06Z EARLY MONDAY MORNING. WEAK DOWNSLOPING IS PROGGED ON MONDAY...WITH NORMAL DIURNAL PATTERNS FOR MONDAY NIGHT. LOW LEVEL TROUGHING EAST OF THE MOUNTAINS TUESDAY POINTS TO SOUTHWESTERLY BOUNDARY LAYER FLOW FOR MOST AREAS. FOR MOISTURE...IT IS VERY DEEP OVER ALL THE CWA SUNDAY EVENING...THEN RAPID DRYING IS PROGGED ON THE MODELS AFTER MIDNIGHT. A TAD OF LOWER LEVEL MOISTURE IS PROGGED TO LINGER OVER THE MOUNTAINS ON MONDAY...WITH THE REST OF THE CWA PRETTY DRY. MONDAY NIGHT THROUGH TUESDAY EVENING ARE PRETTY DRY AS WELL...WITH A BIT OF UPPER LEVEL MOISTURE HERE AND THERE. THE QPF FIELDS HAVE FAIRLY DECENT AMOUNTS OF SNOWFALL FOR THE CWA SUNDAY NIGHT FROM 00Z TO 06Z...THEN A TAD AFTER THAT THOUGH 12Z MONDAY MORNING. THE GFS HAS A TINY BIT OVER THE MOUNTAINS MONDAY...THE NAM IS DRY. MONDAY NIGHT THROUGH TUESDAY EVENING ARE DRY. FOR MOUNTAIN POPS AND SNOW...IT LOOKS PRETTY GOOD CONCERNING THE MOISTURE AND SYNOPTIC SCALE ENERGY. THE OROGRAPHIC ENHANCEMENT WILL MAINLY HELP ZONE 31...BUT NOT IN ZONES 33 AND 34 TOO MUCH. SO WITH THE SHORT TERM FORECASTER'S INPUT...ALONG WITH THE SNOW MODEL...WE WILL GO ADVISORY IN ZONES 33 AND 34...WITH A WARNING IN ZONE 31. FOR POPS OVER THE PLAINS...THERE IS A DECENT SURGE OF COLD AIR WITH DECENT UPSLOPE BEHIND IT...ALBEIT BRIEF. THERE IS DEEP MOISTURE AND SOME SYNOPTIC SCALE UPWARD MOTION. WILL GO WITH 60-80% POPS OVER THE PLAINS. FORECAST SOUNDINGS AND 700 MB TEMPERATURES POINT SHOW THE AIR WILL BE COLD ENOUGH FOR ALL SNOW OVER THE WESTERN PLAINS BY 00Z. WILL GO WITH A SNOW/RAIN MIX FOR THE EASTERN PLAINS. FAIRLY DECENT AMOUNTS OF SNOW WILL BE LIKELY FOR THE PALMER RIDGE...FOOTHILLS...AND IMMEDIATE PLAINS...BUT DO NOT THINK THEY WARRANT HIGHLIGHTS. WILL LINGER A TAD OF SNOW POPS IN THE MOUNTAINS ON MONDAY ONLY...THEN DRY THROUGH TUESDAY NIGHT. THE PLAINS WILL BE DRY MONDAY THROUGH TUESDAY NIGHT. FOR TEMPERATURES...MONDAY'S ARE A TAD WARMER THAN SUNDAY'S HIGHS. TUESDAY'S HIGHS WARM-UP 4-9 C FROM MONDAY'S. FOR THE LATER DAYS WEDNESDAY THROUGH SATURDAY...THERE IS A WEAK UPPER TROUGH PROGGED FOR WEDNESDAY...THEN WEST-SOUTHWESTERLY FLOW ALOFT THROUGH THURSDAY NIGHT. FRIDAY HAS SOUTHWESTERLY FLOW ALOFT WITH A TROUGH/CLOSED LOW GETTING INTO THE GREAT BASIN/UTAH AREA ON SATURDAY. THE GFS AND ECMWF ARE NOT IN GOOD AGREEMENT WITH THIS FEATURE BY SATURDAY. MODELS HAVE QUITE A BIT OF MOISTURE AROUND THROUGH THE FOUR DAYS...WITH TWO OR THREE COLD FRONTS TO MOVE IN AS WELL. IT LOOKS UNSETTLED FOR THE FOUR DAYS. TEMPERATURES LOOK TO BE BELOW SEASONAL NORMALS MOST DAYS...WITH A NEAR NORMAL READINGS ON THURSDAY. AVIATION...GUSTY SOUTHWEST TO WEST WINDS TO GRADUALLY DECREASE AFTER 02Z WITH DIURNAL WIND PATTERN DEVELOPING. EXCEPTION WILL BE AT KBJC WHERE WESTERLY WINDS TO 30 KTS CAN BE EXPECTED THROUGH THE NIGHT. ON SUNDAY...WINDS ACROSS AREA AIRPORTS WILL BECOME WEST TO NORTHWEST 16Z. A COLD FRONT WILL THEN MOVE SOUTH ACROSS THE AREA WITH WINDS SHIFTING TO THE NORTH. MOISTURE WILL INCREASE BEHIND THE FRONT. VFR CONDITIONS TO PREVAIL INITIALLY...WITH CEILINGS BECOMING MVFR AFTER 21Z. RAIN SHOWERS TO DEVELOP DURING THE AFTERNOON...WITH RAIN MIXED WITH SNOW BY 00Z. CHANCE FOR MVFR VISIBILITIES IN MODERATE RAIN AND SNOW SHOWERS. NOT EXPECTING SNOW ACCUMULATION UNTIL AFTER 00Z. && .BOU WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL NOON MDT SUNDAY FOR COZ214>216-241. WINTER WEATHER ADVISORY FROM 3 AM SUNDAY TO MIDNIGHT MDT SUNDAY NIGHT FOR COZ033-034. WINTER STORM WARNING FROM 3 AM SUNDAY TO MIDNIGHT MDT SUNDAY NIGHT FOR COZ031. && SHORT TERM...ENTREKIN LONG TERM....RJK AVIATION...ENTREKIN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1238 AM MDT SUN APR 03 2011 COZ030>051-031200- 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- 1238 AM MDT SUN APR 03 2011 ...RED FLAG WARNING FOR THE FRONT RANGE FOOTHILLS...PARK COUNTY... AND PALMER DIVIDE AREA UNTIL NOON SUNDAY... ...WINTER STORM WARNING MOUNTAINS OF WESTERN GRAND AND JACKSON COUNTIES UNTIL MIDNIGHT SUNDAY NIGHT... ...WINTER WEATHER ADVISORY FRONT RANGE MOUNTAINS AND SUMMIT COUNTY UNTIL MIDNIGHT SUNDAY NIGHT... THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT CRITICAL FIRE WEATHER CONDITIONS WILL REMAIN ACROSS THE FRONT RANGE FOOTHILLS...PARK COUNTY...AND PALMER DIVIDE AREA THROUGH SUNDAY MORNING WITH STRONG GUSTY WINDS IN EXCESS OF 60 MPH AND LOW HUMIDITIES. THEN...A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA RESULTING IN RAIN SHOWERS BY SUNDAY AFTERNOON. THE RAIN WILL CHANGE OVER TO SNOW IN THE LATE AFTERNOON HOURS AS TEMPERATURES FALL SIGNIFICANTLY. THE SNOW WILL CONTINUE INTO THE EVENING BEFORE DECREASING. AT THIS TIME...ACCUMULATIONS OF 2 TO 5 INCHES WILL BE POSSIBLE IN THE FRONT RANGE URBAN CORRIDOR FROM FORT COLLINS THROUGH THE PALMER DIVIDE...WITH THE HEAVIER AMOUNTS LIKELY TO OCCUR FROM THE SOUTHWESTERN SUBURBS OF DENVER ACROSS THE PALMER DIVIDE. LIGHTER AMOUNTS LESS THAN 2 INCHES CAN BE EXPECTED OVER THE EASTERN PLAINS. IN THE MOUNTAINS...SNOW WILL INCREASE THROUGH SUNDAY MORNING AND WILL BE HEAVY AT TIMES THROUGH THE DAY. THE SNOW IS EXPECTED TO DECREASE SUNDAY NIGHT. ACCUMULATIONS OF 7 TO 12 INCHES WILL OCCUR IN THE FRONT RANGE MOUNTAINS AND SUMMIT COUNTY...WITH 8 TO 18 INCHES IN THE MOUNTAINS OF WESTERN GRAND AND JACKSON COUNTIES. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY ANOTHER WEATHER SYSTEM WILL AFFECT THE REGION BY WEDNESDAY BRINGING ANOTHER CHANCE OF SNOW TO THE MOUNTAINS ALONG WITH A CHANCE OF RAIN SHOWERS TO NORTHEAST COLORADO. FOR THURSDAY AND FRIDAY THERE WILL BE A SLIGHT CHANCE OF SNOW SHOWERS IN THE MOUNTAINS WITH A SLIGHT CHANCE OF RAIN SHOWERS OVER THE PLAINS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT...BUT ANY REPORTS OF WIND GUSTS IN EXCESS OF 60 MPH OR SNOW ACCUMULATION WILL BE APPRECIATED. BARJENBRUCH
The national radar mosaic for the moment the first event began.
2 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, April 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: 302501, 302470.