Heavy snow occurred as upslope conditions developed, in and near the Front Range Foothills and Palmer Divide, as the second storm system moved across southern Colorado. 5 inches, 1 mile southwest of Lonetree.
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.
Heavy snow occurred as upslope conditions developed, in and near the Front Range Foothills and Palmer Divide, as the second storm system moved across southern Colorado. Snowfall totals included: 18 inches, 7 miles southwest of Boulder, 17 inches, 10 miles northwest of Blackforest, 8 miles west of Conifer and Intercanyon, 15 inches at Rough and Tumble, 13 inches, 12 miles southwest of Hartsel, 12 inches, 7 miles northwest of Conifer, 10.5 inches at Echo Lake, 10 inches, 3 miles north of Blackhawk, 9 inches at Castle Rock, 2 miles northwest of Fairplay and 5 miles southwest of Sedalia and 6.5 inches, 1 mile southwest of Lonetree.
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 22, 3:15 AM MST, 8 hours 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 415 AM MDT THU APR 22 2004 .SHORT TERM...ALREADY SOME SHOWERS AROUND AS WEAK EAST WINDS ALOFT HAVE ALREADY DEVELOPED. SNOW ASSOCIATED WITH THE INCOMING SYSTEM IS MOVING INTO COLORADO...AND THIS BROAD AREA OF LIFT WILL MOVE INTO THE MOUNTAINS THIS MORNING. MEANWHILE THE AREA OF RAIN ASSOCIATED WITH THE WAVE THAT CAME THROUGH LAST NIGHT IS STARTING TO WRAP BACK IN AS THE LARGER SYSTEM APPROACHES. PLENTY OF MOISTURE AROUND...BUT NO COOLING. I CAN SEE VERY LITTLE ENTRAINMENT OF DRY AIR EITHER. THE LATEST MODEL RUNS ARE WARMER THAN OUR FORECAST...AND LOOK TO BE CORRECT. RESULT IS A HIGHER SNOW LEVEL TONIGHT AND A LATER CHANGEOVER FOR THE FRONT RANGE. ETA SOUNDINGS NEVER DROP THE FREEZING LEVEL BELOW 5400 FEET OVER THE PLAINS...IMPLYING THAT THE LOWER PLAINS WILL NEVER SEE SNOW. NOTEWORTHY THAT THE MODELS ARE TOO COLD TONIGHT AS WELL. WE WILL COMPROMISE AND PLAY A 4-5 THOUSAND FOOT SNOW LEVEL TONIGHT...IF THE LATEST MODELS ARE RIGHT IT WILL BE HIGHER. ADDING CONFIDENCE TO TRIMMING HIGHLIGHTS BACK IS THE 50 DEGREE SOIL TEMPERATURES. HEAVY SNOW WITH WARM GROUND AND AIR ABOVE FREEZING WILL MELT FOR QUITE A WHILE. .LONG TERM DISCUSSION...MODELS ARE SLOWER WITH THE UPPER LOW COMPARED TO LAST NIGHTS 00Z RUNS AND THEY SHOW IT A BIT WARMER IN THE BOUNDARY LAYER THROUGH THE STORMS DURATION. SO TIMING AND THE RAIN/SNOW LINE ARE TO BIG ISSUES ESPECIALLY CONSIDERING CURRENT HIGHLIGHTS. NOW THE GRIDS LINGER THE UPPER CLOSED LOW OVER THE FOUR CORNERS THROUGH LATE FRIDAY AFTERNOON. THEN IT WEAKENS AND PUSHES NORTHEASTWARD RIGHT OVER THE FORECAST AREA THROUGH SATURDAY AFTERNOON. THIS IS SLOWER THEN WHAT I SAW YESTERDAY MORNING. BY SATURDAY EVENING THE FLOW ALOFT BECOMES NORTHWESTERLY...THEN ZONAL BY EARLY SUNDAY AT ONLY MODERATE JET LEVEL SPEEDS. DECENT SYNOPTIC SCALE ASCENT IS PROGGED FOR THE FORECAST AREA FRIDAY...FRIDAY NIGHT...AND SATURDAY MORNING. SUBSIDENCE IS PROGGED BEHIND THE TROUGH AXIS FOR SATURDAY AFTERNOON AND EVENING. CROSS SECTIONS NOW SHOW VERY DEEP MOISTURE FOR THE FORECAST AREA THROUGH FRIDAY NIGHT...THEN A RAPID DECREASE SATURDAY THROUGH MID DAY. THE UPSLOPE IS STILL PRETTY DEEP...AT LEAST THROUGH 500 MB...THROUGH FRIDAY EVENING...THEN IT DECREASES. CONCERNING THE RAIN/SNOW DEAL ...THICKNESS AND TEMPERATURE GRIDS SHOW IT A BIT WARMER THEN LAST NIGHTS RUNS. LOOKING AT THE UPSTREAM AIRMASS TEMPERATURES AND DEW POINT TEMPERATURES...LOOKS LIKE MOST OF THE PLAINS WOULD GET BELOW 35 F FOR HIGHS ON FRIDAY. IT WILL PROBABLY BE A COMPROMISE BETWEEN THE AVN AND ETA GUIDANCE NUMBERS. THE FORECAST SOUNDINGS WET BULB ZERO READINGS ARE WAY HIGH AS WELL. THE SHORT TERM FORECASTER FEELS THE SNOW LEVEL WILL BE A BIT OVER 4000 FEET MSL TONIGHT. STARTING FROM THAT...WITHOUT ANY COLD AIR ADVECTION PROGGED...THE SNOW LEVEL WILL LIKELY CLIMB TO AT LEAST 5000 FEET MSL OR HIGHER BY FRIDAY LATE MORNING. ITS DIFFICULT TO SEE THE DEW POINTS LOWERING BELOW 35 F OVER THE PLAINS FROM NOW THROUGH FRIDAY EARLY EVENING. NOW THE QPF GRIDS ARE ANOTHER STORY. THEY SHOW SIGNIFICANT PRECIPITATION THROUGH FRIDAY NIGHT...WHICH IS ACCEPTABLE. HOWEVER THEY SNOW COPIOUS AMOUNTS OF SNOW ACCUMULATION ACROSS THE PLAINS...WHEN IT WILL LIKELY BE RAIN. THE CURRENT REAL DATA ACROSS WESTERN NEBRASKA SHOWS TEMPERATURES IN THE LOWER 40S WITH RAIN. THE 00Z ETA SHOWS THAT SIGNIFICANT SNOW SHOULD BE FALLING RIGHT NOW...WITH NEAR 12 INCHES EXPECTED BY 12Z THIS MORNING? WITH EVERYTHING CONSIDERED ...SHORT TERM FORECASTER INCLUDED...WILL MERELY CONTINUE THE WATCH OVER SOME OF THE HIGHER PLAINS ZONES WITH THE UNCERTAINTY OF TEMPERATURES. WILL DROP THE WATCH OVER THE REST OF THE PLAINS FURTHER EAST AS IT WILL LIKELY BE TO WARM TO HAVE SIGNIFICANT SNOWFALLS. BUT WILL WARN FOR THE FOOTHILLS...HIGH MOUNTAINS...PARK COUNTY...AND THE PALMER RIDGE. ACCUMULATIONS OFF THE SNOW MODEL FOR THE HIGH AREAS GIVE ANYWHERE FROM 4 TO 9 MORE INCHES FRIDAY AND FRIDAY NIGHT. WILL ALSO EXTENDED THESE HIGHLIGHTS THROUGH FRIDAY NIGHT WITH THE LATEST AND GREATEST MODEL TIMING OF THIS STORM. FOR TEMPERATURES FRIDAY...GRIDS SHOW THEM ABOUT 0-1 C COOLER FROM TODAYS READINGS. THEN A 3-6 C WARM-UP FOR SATURDAY. IN THE EXTENDED PERIOD...SUNDAY THROUGH WEDNESDAY...THE VARIOUS MODELS SHOW WEAK NORTHWESTERLY FLOW ALOFT FOR THE FORECAST AREA SUNDAY...THEN A BROAD UPPER RIDGE PUSHES IN BY MONDAY AND CONTINUES THROUGH THE PERIOD. THERE IS A BIT OF MOISTURE NOTED IN THE NORTHWESTERLY FLOW FOR LATER SUNDAY INTO MONDAY. OTHERWISE IT LOOKS PRETTY DRY THROUGH WEDNESDAY...ESPECIALLY AT THE LOW LEVELS. THICKNESS GRIDS SHOW TEMPERATURES BACK ABOVE NORMALS ON MONDAY THROUGH WEDNESDAY. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING FOR THE HIGH MOUNTAINS...PARK COUNTY...FRONT RANGE FOOTHILLS...AND THE PALMER RIDGE INCLUDING ZONES 33..34..35..36..37..41 FOR TODAY THROUGH FRIDAY NIGHT. WINTER STORM WATCH FOR SOME OF THE PLAINS INCLUDING ZONES 38..39..40..45..46 FOR TONIGHT THROUGH FRIDAY NIGHT. GIMMESTAD/KOOPMEINERS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1056 AM MDT THU APR 22 2004 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- 1056 AM MDT THU APR 22 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT RAIN AND SNOW SHOWERS WILL BECOME WIDESPREAD ACROSS THE AREA DURING THE AFTERNOON...WITH THE SNOW LEVEL EXPECTED TO BE AROUND 6000 FEET. THE SNOW WILL BECOME HEAVY AT TIMES IN THE HIGHER MOUNTAINS...THE FOOTHILLS...SOUTH PARK...AND DOUGLAS COUNTY THIS AFTERNOON. A WINTER STORM WARNING IS IN EFFECT FOR THESE AREAS. THE SNOW LEVEL WILL LOWER TO BETWEEN 5000 AND 5500 FEET AFTER MIDNIGHT TONIGHT WITH RAIN OR RAIN MIXING SNOW ACROSS MUCH OF THE PLAINS. A WINTER STORM WATCH IS IN EFFECT FOR ELEVATIONS ABOVE 5000 FEET...INCLUDING FORT COLLINS... BOULDER...AS WELL AS WESTERN AND SOUTHERN PORTIONS OF THE DENVER METROPOLITAN AREA...STARTING TONIGHT...AS HEAVY SNOW IS POSSIBLE. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY PRECIPITATION WILL CONTINUE INTO FRIDAY NIGHT WITH THE SNOW LEVEL HOVERING BETWEEN 5000 AND 6000 FEET. STORM TOTAL SNOW ACCUMULATIONS OF 1 TO 3 FEET ARE EXPECTED IN THE MOUNTAINS ALONG AND EAST OF THE DIVIDE...WITH 10 TO 20 INCHES IN EASTERN DOUGLAS AND WESTERN ELBERT COUNTIES. IN THE FRONT RANGE CITIES AND THE PLAINS BETWEEN DENVER AND LIMON AMOUNTS ARE MORE UNCERTAIN...BUT THERE IS THE POTENTIAL FOR 6 TO 12 INCHES OF WET SNOW. AT LOWER ELEVATIONS ON THE PLAINS THERE WILL BE SIGNIFICANT RAINFALL...AND SOME SNOW ACCUMULATION IS POSSIBLE BUT AMOUNTS WILL BE LIGHTER. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. COOPER/GARD
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
905 AM MDT THU APR 22 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0900 AM SNOW 3 N BLACK HAWK 39.84N 105.49W
04/22/2004 5.20 INCH GILPIN CO TRAINED SPOTTER
0800 AM SNOW GEORGETOWN 39.72N 105.70W
04/22/2004 1.10 INCH CLEAR CREEK CO CO-OP OBSERVER
0745 AM SNOW 3 NNE GENESEE 39.72N 105.25W
04/22/2004 1.20 INCH JEFFERSON CO TRAINED SPOTTER
0730 AM SNOW 8 NW EVERGREEN 39.72N 105.45W
04/22/2004 4.50 INCH CLEAR CREEK CO TRAINED SPOTTER
0700 AM SNOW ASPEN SPRINGS 39.83N 105.48W
04/22/2004 5.00 INCH GILPIN CO AMATEUR RADIO
0700 AM HEAVY SNOW 1 NW ROLLINSVILLE 39.93N 105.51W
04/22/2004 8.80 INCH GILPIN CO AMATEUR RADIO
0700 AM HEAVY SNOW 1 NW NEDERLAND 39.97N 105.52W
04/22/2004 6.00 INCH BOULDER CO AMATEUR RADIO
0648 AM HEAVY SNOW 5 E NEDERLAND 39.96N 105.41W
04/22/2004 8.00 INCH BOULDER CO TRAINED SPOTTER
0550 AM SNOW 3 WNW CONIFER 39.54N 105.35W
04/22/2004 4.70 INCH JEFFERSON CO TRAINED SPOTTER
0520 AM HEAVY SNOW ESTES PARK 40.37N 105.52W
04/22/2004 6.00 INCH LARIMER CO TRAINED SPOTTER
&&
CLBThe national radar mosaic for the moment the first event began.
4 winter storm. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2004Every state in 2004This day in weather historyWarnings in Colorado, April 2004
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: 5390729, 5390730, 5390731, 5390732.