Alert archive / Colorado / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 36, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 11, 1990, 2:30 PM MDT for Adams County, Denver County, Jefferson County, Colorado. It was in force for 15 min. 2 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Jul 11, 1990, 2:30 PM MDT (20:30 UTC)
- Expired
- Jul 11, 1990, 2:45 PM MDT
- In force
- 15 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
Counties Adams County, CO, Denver County, CO, Jefferson County, CO
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 11, 2:30 PM MDT | Hail 1.75 | Jefferson, CO | |
| Jul 11, 2:35 PM MDT | Hail 1.75 | Denver, CO |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Fort Carson/Butt, CO (KFCS), launched 12:00Z, 8.5 hours before the alert went out and 118 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1472 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- -4 m²/s²
- 0-3 km storm-relative helicity
- 5 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
In the hours before
Special weather statement, Jul 11, 12:48 PM MDT, 1 hour 42 minutes before
COZ011-014-111930- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 1245 PM MDT WED JUL 11 1990 ...THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THE FOOTHILLS... AT 1241 PM NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED THUNDERSTORMS BEGINNING TO FIRE OVER THE NORTHERN FOOTHILLS AND PALMER DIVIDE. THE STRONGEST STORM WAS LOCATED 7 MILES EAST OF ESTES PARK...AND MOVING SOUTHEAST AT 20 MPH. STORMS WILL CONTINUE TO DEVELOP ALONG THE FOOTHILLS EARLY THIS AFTERNOON...AND MOVE OUT INTO THE PLAINS BY MID AFTERNOON. STORMS SHOULD CONTINUE MOVING SOUTHEAST AT 15 TO 25 MPH. LOCALLY HEAVY RAIN...HAIL...AND FREQUENT LIGHTNING WILL BE POSSIBLE WITH STORMS THIS AFTERNOON. RTG
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 1:00 PM MDT | Severe Thunderstorm Warning | BOU | Boulder, Larimer | 40 min |
| Jul 11, 1:42 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Boulder, Jefferson | 48 min |
| Jul 11, 2:15 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver, Jefferson | 90 min |
| Jul 11, 3:10 PM MDT | Severe Thunderstorm Warning | BOU | Douglas | 30 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 1990Every severe thunderstorm warning in 1990
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.