Hail, Weld
- When
- September 1, 1:59 PM MST
- Where
- Weld County, 10 mi E of Platteville
- Measured
- 0.75 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.220, -104.630
Tornadoes and Hail in Colorado, September 1, 1999
Heavy rain, large hail, damaging straight-line winds, tornadoes and lightning struck portions of the northeast plains of Colorado. In Fort Collins, large hail caused extensive damage to automobiles in the area.
Where it happened
Every event with a place to put it; 1 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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 10
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 happened
The episode as NWS BOU wrote it up.
Heavy rain, large hail, damaging straight-line winds, tornadoes and lightning struck portions of the northeast plains of Colorado. In Fort Collins, large hail caused extensive damage to automobiles in the area. In addition, large tree limbs, 5 inches in diameter, were snapped along with a few power poles that measured 8 inches in diameter. Millet crops in the area were also flattened, while corn and sunflower crops were stripped. Lightning struck the Fort Collins Police Department's radio tower, temporarily disabling the 911 system. Heavy rain, up to a half an inch in 15 minutes, caused minor flooding at the CSU Campus. Two small tornadoes touched down briefly near the towns of Iliff and La Salle, but did no damage.
The radar
The Denver radar (KFTG), 49 km away, was scanning. The volume nearest the first event began at 20:57 UTC.
Event by event
5 hail, 2 tornado, 2 thunderstorm wind, 1 lightning. Local standard time, as filed.
Hail, Larimer
- When
- September 1, 2:00 PM MST
- Where
- Larimer County, 1 mi E of Red Feather Lakes
- Measured
- 0.75 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.800, -105.570
Tornado, Weld
- When
- September 1, 2:13 PM MST
- Where
- Weld County, 5 mi E of La Salle
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 25 yd
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.350, -104.600
Hail, Weld
- When
- September 1, 2:21 PM MST
- Where
- Weld County, 6 mi E of La Salle
- Measured
- 0.75 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.350, -104.580
Thunderstorm Wind, Douglas
- When
- September 1, 3:33 PM MST
- Where
- Douglas County, Castle Rock
- Measured
- 50 kt (58 mph)
- Reported by
- TRAINED SPOTTER
- Coordinates
- 39.370, -104.870
Thunderstorm Wind, Logan
- When
- September 1, 4:26 PM MST
- Where
- Logan County, 17 mi WNW of Sterling
- Measured
- 57 kt (66 mph)
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.730, -103.500
Hail, Logan
- When
- September 1, 4:26 PM MST to 4:35 PM MST
- Where
- Logan County, Sterling to 17 mi WNW of Sterling
- Measured
- 1.5 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.730, -103.500
Tornado, Logan
- When
- September 1, 4:43 PM MST
- Where
- Logan County, 8 mi W of Iliff
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 25 yd
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.750, -103.220
Lightning, Larimer
- When
- September 1, 5:38 PM MST
- Where
- Larimer County, Ft Collins
- Reported by
- NEWSPAPER
- Coordinates
- 40.666, -105.461 (the zone’s center; the record gives no point)
Hail, Larimer
- When
- September 1, 5:46 PM MST
- Where
- Larimer County, Ft Collins
- Measured
- 1 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.580, -105.080
What these are
- 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.
- Thunderstorm Wind
- Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
- Lightning
- A lightning strike that killed, injured or caused damage.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Drought in Ohio, September 1 to 30, 1999
- Flooding and Hail in Arizona, September 1 to 20, 1999
- Drought in Kentucky, September 1 to 30, 1999
- Drought in New Jersey, September 1 to 27, 1999
- Tropical Storm in North Carolina, September 1 to 5, 1999
- Drought in New York, September 1 to 30, 1999
- Flooding in North Dakota, September 1 to 30, 1999
- Drought in Delaware, September 1 to 17, 1999
- Drought in Pennsylvania, September 1 to 30, 1999
- Drought in Virginia, September 1 to 30, 1999
- Wildfire in California, September 1 to 9, 1999
- Hail and Damaging Wind in Nebraska, September 1, 1999
More
Every storm in Colorado in 1999Every state in 1999This day in weather historyThe tornado archive for Colorado, 1999Warnings in Colorado, September 1999
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: 5718020, 5718021, 5718114, 5718115, 5718116, 5718117, 5718118, 5718119, 5718120, 5718121.