Another spring storm brought heavy snow to portions of the North Central Mountains, Front Range Foothills and South Park. Snowfall totals included: 23 inches, 1 mile south of Fritz Peak, 21 inches, 4 miles southwest of Estes Park, 20 inches at Allenspark and 3 miles north of Alma, 18 inches, 1 mile east of Buckhorn Mountain, 17 inches, 2 miles west of Jamestown, 16 inches, 3 miles north of…
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.
Another spring storm brought heavy snow to portions of the North Central Mountains, Front Range Foothills and South Park. Snowfall totals included: 23 inches, 1 mile south of Fritz Peak, 21 inches, 4 miles southwest of Estes Park, 20 inches at Allenspark and 3 miles north of Alma, 18 inches, 1 mile east of Buckhorn Mountain, 17 inches, 2 miles west of Jamestown, 16 inches, 3 miles north of Blackhawk, 14 inches at Coal Creek Canyon and Estes Park, 13 inches and Idaho Springs and 4 miles northeast of Nederland, 12 inches at Hoosier Pass and 4 miles west of Jamestown, 10 miles southwest of Livermore and 3 miles east southeast of Red Feather Lakes, 11 inches at Aspen Springs, Hourglass Lake and Virginia Dale and 10 inches, 1 mile west of Bergen Park. Elsewhere, snowfall amounts ranged from 5 to 9 inches.
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 21, 2:00 PM MST, 3 hours earlier.
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
300 PM MDT SAT APR 21 2001
SHORT TERM DISCUSSION: MESOSCALE BOUNDARY HAS DEVELOPED E-W THROUGH
DENVER WITH AIR MASS MOISTENING NICELY ON THE N SIDE. REINFORCING SURGE
COMING THROUGH THE NRN BORDER NOW AND STRONG SYNOPTIC SCALE PRESSURE
FALLS TAKING SHAPE AROUND TRINIDAD. STRONG CYCLOGENESIS WITH HEAVY
PRECIP DEVELOPING OVERNIGHT PER ETA LOOKS GOOD...THE MAIN QUESTION
IS TEMPERATURES. BEST DYNAMIC LIFT DOES NOT ARRIVE UNTIL AFTER
MIDNIGHT AND FLOW WILL BE PRETTY ELY TOO...GREAT FOR PRECIP BUT NOT
MUCH COOLING. THE COLD AIR WILL RUSH IN BEHIND THE TROUGH AXIS
SOMETIME IN THE MORNING...WITH SIGNIFICANT FRONTOGENESIS ALONG A
NE-SW AXIS ACROSS THE AREA BY MORNING. MODEL GUIDANCE NOT CLEAR
CUT...ETA PUTS US RIGHT ON THE THRESHOLD OF RAIN/SNOW DURING THE
EARLY MORNING...GENERATING 6 INCHES OF SNOW ALONG THE FOOTHILLS BY
12Z WITH ALL RAIN EAST OF GREELEY-DIA. ETA SOUNDINGS AT DIA LOOK
TOO WARM FOR SNOW YET AT 12Z...BUT A DEGREE OR TWO COLDER OR A FEW
MILES NORTH AND WEST COULD MAKE A CRITICAL DIFFERENCE. IN ANY
EVENT. BOILS DOWN TO A GUT FEELING THAT ONCE THE REALLY GOOD SNOW
SETS IN TOWARD DAWN THERE WILL BE A LITTLE MORE COOLING. I WILL GO
AHEAD WITH THE WARNING ALONG THE FRONT RANGE STARTING LATE TONIGHT.
THE WATCH CAN STAY UP FOR THE PLAINS...WITH LEAST LIKELIHOOD S OF
THE PALMER DIVIDE IN LINCOLN COUNTY. LESS THAN ADVISORY AMOUNTS
EXPECTED TONIGHT IN ZONES 30-32 SO I WILL DROP THE WATCH...MAYBE AN
ADVISORY TOMORROW. GIMMESTAD
LONG TERM DISCUSSION...POTENTIAL FOR SIGNIFICANT SNOWFALL REMAINS
HIGH FOR MTN AREAS MAINLY EAST OF CONT DVD...THE FRONT RANGE URBAN
CORRIDOR AND FOR PORTIONS OF NERN PLAINS OF CO THRU 2ND PERIOD.
MODELS ALL DOING A GOOD JOB INITIALLY LARGE SCALE FEATURES WITH H5
LOW APCHG WRN AZ ATTM. MODELS LIFT CLOSED H5 LOW OUT OF AZ AND ACRS
SERN CO SUN MORNING. AS USUAL NGM AND THE NAVYS NOGAPS MODELS APR
SLOWER...WARMER AND DRIER THAN OTHER MODELS...WHILE ETA WAS THE
COLDEST AND WETTEST. AT THIS TIME PREFER ETA SOLUTION FOR VARIOUS
REASONS...NOTABLY FOR ITS WIND AND MOISTURE FIELDS. THUS WILL BASE
FCST OUT THRU MON ON THE ETA. AT 12Z/SUN ETA SHOWS LOW OVR SERN CO
VERTICALLY STACKED UP THRU 500 MBS...AND UP THRU 400 MBS BY
18Z/SUN. ETA WIND GRIDS SHOW E-NELY UPSLOPE FLOW DEEPEST/STRONGEST
BTWN 09Z-18Z/SUN...ABOUT SAME TIME WHEN ETA AND OTHER MODELS SHOW
STRONGEST 700-300MB QG FORCING AND STEEPEST SFC-500MB LAPSE RATES
OVR THE CWFA. DO NOT RECALL SEEING AS MUCH CYCLOGENESIS WITH SYSTEM
THAT PRODUCED BIG SNOWFALL LAST MONDAY. SO EVEN THOUGH ETA KEEPS
BNDRY LYR TEMPS ABV FREEZING DURING THE DAY SUN...BLV THERMODYMANIC
PROCESSES WILL KEEP PCPN FROZEN IN AREAS AOA 4500 FT ELEV. AS LOW
DEEPENS IN SERN CO SHOULD SEE BARRIER JET FORMING UP AGAINST FTHLS
DURING THE ERLY MRNG HRS SUN...WITH MOIST E-NELY FLOW OVERRUNNING
COLD AIR RAMMING DOWN FRONT RANGE. BECAUSE OF THIS BELIEVE URBAN
CORRIDOR IN BEST POSITION TO RECEIVE GREATEST SNOW AMTS. ETA GIVES
UPWARDS OF 1.30 INCHES LIQUID AND ARND 12 INCHES OF SNOW AT DENVER
BY END OF STORM. THIS ALL DEPENDS ON WHEN THE RAIN TONIGHT CHANGES
OVER TO SNOW. NOW APRS MOST OF SNOW WILL FALL IN THE URBAN CORRIDOR
AND DEN METRO AREA BEFORE 21Z/SUN. SHOULD ALSO SEE BLOWING AND
DRIFTING SNOW DURING SAME PD. SO TRAVELERS...AG INTERESTS AND LIVE
STOCK GROWERS TAKE NOTICE.
FARTHER OUT ONTO THE PLAINS...CHANCES FOR MEASURABLE SNOW
ACCUMULATION NOT AS CLEAR CUT. DEPENDING ON WHERE BAROCLINIC ZONE
ALIGNS ITSELF COULD SEE PCPN IN THE FORM OF RAIN FOR PORTION OF THE
DAY SUN SINCE DAYTIME TEMPS PROGD IN UPR 30S/LOWER 40S. NOT UNTIL
COLD AIR WRAPS BACK AROUND LOW AS IT EJECTS NEWRD OUT OF CO SUN AFTN
WILL WE SEE SNOW BEGIN PILING UP IN ZNS 46/47/48/49/50 AND 51. IN
ADDITION TO SNOWFALL...WHICH COULD BE HVY AT TIMES...COULD ALSO SEE
VRY STG/GUSTY NLY WINDS PRODUCING MUCH BLOWING AND DRIFTING ON THE
PLAINS SUN AFTN AND EVE. SINCE THE ONSET AND AMT OF SNOW STILL
REMAINS IN DOUBT FOR THIS PART OF CWFA WILL KP THEM UNDER A WINTER
STORM WATCH.
IN THE EXTENDED PERIOD...UNSEASONABLY COLD WET SYSTEM MOVES OUT OF
AREA BY MON AFTERNOON WITH BIG WARMUP PROGD BY MIDWEEK AS BROAD
HIGH PRES RIDGE ANCHORS ITSELF OVR THE WRN CONUS. BAKER
.DEN...WINTER STORM WARNING TONIGHT AND SUN FRONT RANGE MTNS/FTHLS...
ZNS 33>36.
WINTER STORM WARNING LATE TONIGHT AND SUN URBAN CORRIDOR...
ZNS 38>41.
WINTER STORM WATCH PLAINS SUN...ZNS 42>51.COZ030>051-212000- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1200 PM MDT SAT APR 21 2001 THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES ADAMS ARAPAHOE BOULDER CLEAR CREEK DENVER DOUGLAS ELBERT GILPIN GRAND JACKSON JEFFERSON LARIMER LINCOLN LOGAN MORGAN PARK PHILLIPS SEDGWICK SUMMIT WASHINGTON WELD SYNOPSIS: A STRONG SPRING STORM WILL DEVELOP OVER EASTERN COLORADO TONIGHT...MOVING EAST BY SUNDAY NIGHT. THIS AFTERNOON SNOW SHOWERS WILL BE INCREASING IN THE MOUNTAINS WITH RAIN SHOWERS DEVELOPING. THE RAIN AND SNOW SHOULD BECOME WIDESPREAD IN AND NEAR THE MOUNTAINS DURING THE EVENING...WITH THE SNOW LEVEL LOWERING TO 6 OR 7 THOUSAND FEET BY MIDNIGHT. HEAVY SNOW IS EXPECTED TO DEVELOP IN THE MOUNTAINS AND POSSIBLY ALONG THE FRONT RANGE CITIES BY SUNRISE SUNDAY. OUTLOOK FOR SUNDAY: HEAVY SNOW AND STRONG WINDS ARE LIKELY IN THE MOUNTAINS AND ACROSS AT LEAST A PORTION OF NORTHEASTERN COLORADO. THE EASTWARD AND SOUTHERN EXTENT OF THE HEAVY SNOW IS STILL UNCERTAIN. STAY TUNED FOR UPDATES LATER THIS )AFTERNOON. GIMMESTAD
The 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 2001Every state in 2001This day in weather historyWarnings in Colorado, April 2001
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: 5238164, 5238165, 5238166, 5238167.