Alert archive / Colorado / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 28, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 6, 1997, 4:25 PM MDT for Boulder County, Jefferson County, Weld County, Colorado. It was in force for 50 min. 1 report came from inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.
The facts
- Issued
- Jun 6, 1997, 4:25 PM MDT (22:25 UTC)
- Expired
- Jun 6, 1997, 5:15 PM MDT
- In force
- 50 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Boulder County, CO, Jefferson County, CO, Weld County, CO
The radar
The Denver radar (KFTG), 38 km from the middle of the area, began a volume at 22:28 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 6, 4:35 PM MDT | Hail 0.75 | Henderson, 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.
The nearest sounding before it
Fort Carson/Butt, CO (KFCS), launched 12:00Z, 10.4 hours before the alert went out and 142 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
- 42 J/kg
- Mixed-layer CIN
- -358 J/kg
- Mixed-layer LCL
- 1036 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 10 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDEN 062227
SVRDEN
COC001-013-059-123-062315-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
425 PM MDT FRI JUN 6 1997
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 515 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...
IN NORTHEAST COLORADO
SOUTHEASTERN BOULDER...NORTHEASTERN JEFFERSON...NORTHWESTERN
ADAMS AND SOUTHWESTERN WELD
INCLUDING THE FOLLOWING LOCATIONS
BOULDER...BROOMFIELD...COMMERCE CITY...NORTHGLENN...THORNTON
...WESTMINSTER...BARR LAKE...BRIGHTON...DACONO...ERIE...
FEDERAL HEIGHTS...FIRESTONE...FREDERICK...LAFAYETTE...
LOUISVILLE AND SUPERIOR
AT 423 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 3 MILES NORTHEAST OF THORNTON...OR ABOUT 11 MILES
NORTH OF DENVER.
THE STORM WAS NEARLY STATIONARY BUT OTHER STORMS ARE EXPECTED TO DEVELOP.
THESE SEVERE THUNDERSTORMS MAY PRODUCE SHORT LIVED TORNADOES WITH
LITTLE OR NO ADVANCE WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN
A STURDY STRUCTURE SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A
TORNADO IS SPOTTED.
VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.
HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY
MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO
RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS.
REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN DENVER.
TA
LAT...LON 3997 10475 3981 10480 3979 10493 3984 10516
4003 10529 4017 10492What 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, Jun 6, 10:58 AM MDT, 5 hours 27 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 11AM MDT FRIDAY JUNE 6 1997 ...HIGH AND FAST RIVERS AGAIN THIS WEEKEND... HIGH RIVER LEVELS IN NORTHEASTERN COLORADO WILL BE THE RULE THROUGHOUT THE COMING WEEKEND. THERE WILL BE LITTLE OR NO ADDITION OF WATER TO THE RIVERS DUE TO SNOWMELT...BUT LOCALLY HEAVY RAINS ARE FORECAST OVER THE AREA THROUGH SUNDAY AND THESE MAY PRODUCE FLASH FLOODING ON SMALLER STREAMS. PERSONS ON OR NEAR RIVERS AND STREAMS IN NORTHEASTERN COLORADO THIS WEEKEND SHOULD BE ALERT FOR RAPID RISES IN RIVER LEVELS. RESERVOIR RELEASES CONTINUE TO ACCOUNT FOR MUCH OF THE HIGH WATER DOWNSTREAM OF DAMS THROUGHOUT THE AREA. THESE RELEASES ARE BEING CLOSELY MONITORED AND ANY FLOODING RESULTING FROM THEM SHOULD BE MINOR UNLESS SIGNIFICANT RAIN FALLS IN THE VICINITY. TO REPEAT...THE NEXT FEW DAYS WILL SEE THE HIGHEST RIVER LEVELS OF THE SEASON ON MOST STREAMS IN NORTHEASTERN COLORADO AND ANYONE ON OR NEAR THEM SHOULD EXERCISE CAUTION. IN ADDITION...MUD AND ROCK SLIDES MAY BE A CONCERN IN SOME BACK COUNTRY AREAS. TUNNELL
Special weather statement, Jun 6, 11:19 AM MDT, 5 hours 6 minutes before
COZ030-032>050-070600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1115 AM MDT FRI JUN 6 1997 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: SUFFICIENT MOISTURE FOR THUNDERSTORMS CONTAINING HEAVY RAIN WILL CONTINUE TO FEED INTO THE AREA TODAY AND TONIGHT IN DEEP UPSLOPE FLOW. HEAVY RAIN AND SMALL HAIL WILL BE THE MAIN THREATS WITH THE THUNDERSTORMS AS THE FLOW ALOFT OVER COLORADO REMAINS WEAK. THUNDERSTORMS WILL INITIATE OVER THE MOUNTAINS EARLY THIS AFTERNOON AND REMAIN NEARLY STATIONARY IN THE UPSLOPE FLOW. THEREFORE... HOURLY RAINFALL RATES OF 1 TO 2 INCHES PER HOUR ARE LIKELY. MOST THUNDERSTORMS ARE EXPECTED TO STAY IN AND CLOSE TO THE HIGHER TERRAIN TODAY BUT A FEW MAY DEVELOP IN THE URBAN CORRIDOR AND ON THE PLAINS THIS AFTERNOON AND EVENING. THESE LOWER ELEVATION STORM WILL ALSO HAVE THE POTENTIAL FOR HEAVY RAIN...HAIL AND GUSTY WINDS UPTO 40 MPH. ALTHOUGH THUNDERSTORMS ARE NOT EXPECTED TO REACH SEVERE LEVELS TODAY AND TONIGHT...HEAVY RAIN ESPECIALLY IN THE HIGH COUNTRY NEEDS TO BE MONITORED. SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY. FREDIN
Special weather statement, Jun 6, 2:09 PM MDT, 2 hours 16 minutes before
COZ030-032>050-070600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 205 PM MDT FRI JUN 6 1997 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: SUFFICIENT MOISTURE FOR THUNDERSTORMS CONTAINING HEAVY RAIN WILL CONTINUE TO FEED INTO THE AREA TODAY AND TONIGHT IN DEEP UPSLOPE FLOW. HEAVY RAIN AND HAIL WILL BE THE MAIN THREATS WITH THE THUNDERSTORMS AS THE FLOW ALOFT OVER COLORADO REMAINS WEAK. THUNDERSTORMS HAVE DEVELOPED RAPIDLY OVER THE URBAN CORRIDOR AREA EARLY THIS AFTERNOON AND HAVE A HISTORY OF PRODUCING HEAVY RAIN...LARGE HAIL AND FUNNEL CLOUDS. THE POTENTIAL EXISTS FOR THUNDERSTORMS TO PASS THROUGH THE AREA INTO THE EVENING HOURS. HOURLY RAINFALL RATES OF 1 TO 2 INCHES PER HOUR AND HAIL UPTO 2 INCHES IN DIAMETER ARE LIKELY WITH THE THUNDERSTORMS. THEREFORE...SPOTTER ACTIVATION WILL BE NEEDED FOR THE REST OF THE AFTERNOON INTO THE EVENING. FREDIN
Special weather statement, Jun 6, 2:42 PM MDT, 1 hour 43 minutes before
COZ036-035-037-041-039-038-040-062300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 240 PM MDT FRI JUN 6 1997 ...HEAVY RAINS MOVING INTO THE FOOTHILLS... THUNDERSTORMS WITH HEAVY RAINS ARE MOVING INTO THE FOOTHILLS OF LARIMER...BOULDER...JEFFERSON...DOUGLAS...CLEAR CREEK...GILPIN AND PARK COUNTIES. RADAR AND PRECIPITATION GAUGES SHOW THAT UPWARDS OF AN INCH OF RAIN HAS FALLEN FROM SOME OF THESE STORMS OVER THE DENVER METRO AREA AND SOME OF THE HIGHER FOOTHILLS LOCATIONS. WITH RIVERS ALREADY RUNNING HIGH FROM SNOWMELT...THESE HEAVY RAINS COULD CAUSE SOME OF THE RIVERS TO RISE RAPIDLY LATER TODAY AND TONIGHT WHICH COULD LEADING TO MORE SIGNIFICANT FLOODING. PERSONS LIVING OR TRAVELING NEAR STREAMS ALONG THE FRONT RANGE OF NORTHEAST COLORADO SHOULD BE ON THE LOOKOUT FOR RAPIDLY RISING RIVER LEVELS THIS AFTERNOON AND TONIGHT AND BE PREPARED TO TAKE QUICK ACTION SHOULD MORE SIGNIFICANT FLOODING OCCUR.
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 6, 1:36 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver | 39 min |
| Jun 6, 1:56 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Douglas, Jefferson | 34 min |
| Jun 6, 1:56 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver | 34 min |
| Jun 6, 2:35 PM MDT | Severe Thunderstorm Warning | BOU | Boulder | 25 min |
| Jun 6, 3:37 PM MDT | Severe Thunderstorm Warning | BOU | Jefferson | 38 min |
| Jun 6, 4:25 PM MDT | Severe Thunderstorm Warning | BOU | Adams | 50 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 1997Every severe thunderstorm warning in 1997
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; radar from the NEXRAD Level II archive.