Tornadoes and Flash Flood in Colorado, July 9, 2001

Name: Tornadoes and Flash Flood in Colorado, July 9, 2001
Start: 2001-07-09T12:30
End: 2001-07-09T22:45
Location: Colorado

July 9, 2001 · NWS BOU · 8 events in 4 counties and zones

2 lightning, 2 hail, 2 tornado, 1 heavy rain, 1 flash flood, as filed by the National Weather Service.

Where it happened

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.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 8

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.

What forecasters said that day

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 Jul 9, 2:30 AM MST, 10 hours earlier.

Area forecast discussion, Jul 9, 2:30 AM MST, 10 hours before

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
330 AM MDT MON JUL 9 2001

LOOKS LIKE WE COULD COPY YESTERDAYS DISCUSSION AND PUT IT IN FOR
TODAY.  NOTHING MUCH HAS CHANGED IN THE LAST 24 HOURS...EXCEPT
GROUND IS BECOMING WETTER.  WHILE LAST EVENINGS CONVECTION DID NOT
EVOLVE INTO A MESOSCALE CONVECTIVE SYSTEM...WE SAW PLENTY OF RAIN IN
THE DENVER METRO AREA.

MODELS SUGGEST DEVELOPMENT OF AN MCS WITH MORE WIDESPREAD RAINFALL
THIS EVENING AS LOW LEVEL JET ACTS TO ENHANCE STORMS AND KEEP THEM
GOING PAST MIDNIGHT.  AT THIS TIME...LOOKS LIKE BEST LOW LEVEL
CONVERGENCE AND THUS THUNDERSTORM INITIATION THIS AFTERNOON WILL
ONCE AGAIN FOCUS ON THE HIGHER TERRAIN FROM SOUTHERN JEFFERSON AND
DOUGLAS COUNTIES THROUGH THE SOUTHERN SUBURBS OF DENVER INTO
ARAPAHOE COUNTY.  ALTHOUGH THIS WOULD BE PRIMARY THREAT AREA FOR
HEAVY RAINFALL AND POSSIBLE FLOODING...CANT RULE OUT HEAVY RAINERS
ANYWHERE ACROSS THIS CWA GIVEN PRECIPITABLE WATER VALUES OF 1.1 TO
1.4 INCHES...TRAINING ECHOES DUE TO INCREASING LOW LEVEL JET...AND
FAIRLY DEEP BUT WEAK EAST/SOUTHEAST FLOW TO HELP ANCHOR STORMS.
DAY SHIFT WILL LIKELY HAVE TO ISSUE FLASH FLOOD WATCH IF THINGS ARE
COMING TOGETHER RIGHT.

CAPES AGAIN MAX OUT IN THE 1800-2500 J/KG RANGE.  SUFFICIENT WIND
SHEAR EXISTS FOR A COUPLE MORE SEVERE STORMS.

WITH MID LEVEL TEMPS COOLING ABOUT 1-2C...MAY BE DIFFICULT (BUT NOT
IMPOSSIBLE) TO REACH 90F IN DENVER.

NOT MUCH CHANGE FOR TUESDAY WITH ABUNDANT LOW LEVEL MOISTURE AND
SOME MONSOONAL MOISTURE ALOFT TO WORK WITH FOR ANOTHER ROUND OF
AFTERNOON AND NIGHTTIME STORMS AND LOCALLY HEAVY RAINFALL.  NO
CHANGES TO THE EXTENDED.

BARJENBRUCH

.DEN...NONE.

In the hours before

Local storm report, Jul 9, 8:15 AM MST, 4 hours 15 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
915 AM MDT MON JUL 09 2001

...PRELIMINARY STORM REPORT FOR JULY 08 2001...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1242 PM    GLEN HAVEN                CO   0.75 INCH HAIL
07/08/01   LARIMER

1252 PM    15 WNW STERLING           CO   0.75 INCH HAIL
07/08/01   LOGAN

0423 PM    SOUTHERN DENVER           CO   0.88 INCH HAIL
07/08/01   JEFFERSON

0441 PM    ENGLEWOOD                 CO   1.25 INCH HAIL
07/08/01   JEFFERSON

0442 PM    LITTLETON                 CO   0.75 INCH HAIL
07/08/01   ARAPAHOE

0445 PM    ENGLEWOOD                 CO   62 MPH TSTM WIND GUST
07/08/01   ARAPAHOE                       MEASURED BY SPOTTER

0448 PM    DENVER                    CO   1.00 INCH HAIL
07/08/01   DENVER

0507 PM    ENGLEWOOD                 CO   1.00 INCH HAIL
07/08/01   ARAPAHOE

0520 PM    DENVER ITNL AIRPORT       CO   63 MPH TSTM WIND GUST
07/08/01   DENVER

COOPER

Local storm report, Jul 9, 10:15 AM MST, 2 hours 15 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT MON JUL 09 2001

...PRELIMINARY STORM REPORT FOR JULY 08 2001...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1252 AM    15 WNW STERLING           CO   0.75 INCH HAIL
07/08/01   LOGAN

1242 PM    GLEN HAVEN                CO   0.75 INCH HAIL
07/08/01   LARIMER

0423 PM    SOUTHERN DENVER           CO   0.88 INCH HAIL
07/08/01   JEFFERSON

0441 PM    ENGLEWOOD                 CO   1.25 INCH HAIL
07/08/01   JEFFERSON

0442 PM    LITTLETON                 CO   0.75 INCH HAIL
07/08/01   ARAPAHOE

0445 PM    ENGLEWOOD                 CO   62 MPH TSTM WIND GUST
07/08/01   ARAPAHOE                       MEASURED BY SPOTTER

0448 PM    DENVER                    CO   1.00 INCH HAIL
07/08/01   DENVER

0507 PM    ENGLEWOOD                 CO   1.00 INCH HAIL
07/08/01   ARAPAHOE

0520 PM    DENVER INTL AIRPORT       CO   63 MPH TSTM WIND GUST
07/08/01   DENVER

COOPER

Local storm report, Jul 9, 10:56 AM MST, 1 hour 34 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT MON JUL 09 2001

...PRELIMINARY STORM REPORT FOR JULY 08 2001...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1252 AM    15 WNW STERLING           CO   0.75 INCH HAIL
07/08/01   LOGAN

1242 PM    GLEN HAVEN                CO   0.75 INCH HAIL
07/08/01   LARIMER

0423 PM    SOUTHERN DENVER           CO   0.88 INCH HAIL
07/08/01   JEFFERSON

0441 PM    ENGLEWOOD                 CO   1.25 INCH HAIL
07/08/01   JEFFERSON

0442 PM    LITTLETON                 CO   0.75 INCH HAIL
07/08/01   ARAPAHOE

0445 PM    ENGLEWOOD                 CO   62 MPH TSTM WIND GUST
07/08/01   ARAPAHOE                       MEASURED BY SPOTTER

0448 PM    DENVER                    CO   1.00 INCH HAIL
07/08/01   DENVER

0507 PM    ENGLEWOOD                 CO   1.00 INCH HAIL
07/08/01   ARAPAHOE

0520 PM    DENVER INTL AIRPORT       CO   63 MPH TSTM WIND GUST
07/08/01   DENVER

COOPER

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 lightning, 2 hail, 2 tornado, 1 heavy rain, 1 flash flood. Local standard time, as filed.

Lightning, Summit

When: July 9, 12:30 PM MST
Where: Summit County, 5 mi ESE of Dillon
Reported by: NEWSPAPER
Coordinates: 39.634, -106.116 (the zone’s center; the record gives no point)

Lightning struck a home in Keystone, damaging the roof.

Hail, Morgan

When: July 9, 5:50 PM MST
Where: Morgan County, Hoyt
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 40.017, -104.067

Hail, Morgan

When: July 9, 7:30 PM MST
Where: Morgan County, 17 mi S of Brush
Measured: 1.5 in hail
Reported by: TRAINED SPOTTER
Coordinates: 40.000, -103.617

Tornado, Morgan

When: July 9, 7:44 PM MST
Where: Morgan County, 2 mi SE of Brush
Rating: F0
Path length: 0.1 mi
Path width: 25 yd
Reported by: GENERAL PUBLIC
Coordinates: 40.233, -103.583

A small tornado touched down but did no damage.

Tornado, Morgan

When: July 9, 8:10 PM MST
Where: Morgan County, 6 mi S of Brush
Rating: F0
Path length: 0.1 mi
Path width: 25 yd
Reported by: GENERAL PUBLIC
Coordinates: 40.167, -103.617

A small tornado touched down but did no damage.

Heavy Rain, Logan

When: July 9, 9:00 PM MST
Where: Logan County, Sterling
Reported by: NEWSPAPER
Coordinates: 40.725, -103.110 (the zone’s center; the record gives no point)

A wet microburst caused the roof of a service garage at a Cadillac dealership to collapse. Four cadillacs being serviced at the time were damaged.

Lightning, Sedgwick

When: July 9, 9:00 PM MST
Where: Sedgwick County, Sedgwick
Reported by: NEWSPAPER
Coordinates: 40.876, -102.352 (the zone’s center; the record gives no point)

Lightning ignited a fire in the basement of a home causing minor damage.

Flash Flood, Morgan

When: July 9, 9:00 PM MST to 10:45 PM MST
Where: Morgan County, Brush
Reported by: EMERGENCY MANAGER
Coordinates: 40.263, -103.810 (the zone’s center; the record gives no point)

The combination of heavy rain and hail caused flooding and flash flooding problems in the Brush and Fort Morgan areas. Several roads as well as the basments of home and businesses were flooded.

What these are

Lightning: A lightning strike that killed, injured or caused damage.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Colorado in 2001 Every state in 2001 This day in weather history The tornado archive for Colorado, 2001 Warnings in Colorado, July 2001

Sources

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: 5267143, 5267137, 5267138, 5267139, 5267140, 5267141, 5267142, 5267144.