Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 104, NWS Denver/Boulder, CO

July 19, 1997Adams County, Arapahoe County, Denver County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 19, 1997, 4:39 PM MDT for Adams County, Arapahoe County, Denver County, Colorado. It was in force for 36 min. 1 report 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 19, 1997, 4:39 PM MDT (22:39 UTC)
Expired
Jul 19, 1997, 5:15 PM MDT
In force
36 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Adams County, CO, Arapahoe County, CO, Denver County, CO

The radar

The Denver radar (KFTG), 4 km from the middle of the area, began a volume at 22:39 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

TimeReportWhereRemark
Jul 19, 4:45 PM MDTHail 1.25Denver, 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

Denver, CO (KDNR), launched 12:00Z, 10.7 hours before the alert went out and 111 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.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 1997-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 31 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 1997-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
31 J/kg
Mixed-layer CIN
-303 J/kg
Mixed-layer LCL
1548 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDEN 192242
SVRDEN
COC001-005-031-192315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING...CORRECTED
NATIONAL WEATHER SERVICE DENVER CO
439 PM MDT SAT JUL 19 1997

CORRECTED LOCATION

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
     NORTHWESTERN ARAPAHOE...EASTERN DENVER AND WESTERN ADAMS

INCLUDING THE FOLLOWING LOCATIONS
     AURORA...DENVER INTERNATIONAL AIRPORT...AND NORTHEASTERN      
DENVER

AT 439 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM OVER WEST CENTRAL AURORA...OR ABOUT 7 MILES EAST
OF DENVER.

THIS STORM WAS PRODUCING HAIL AT LEAST 1 INCH IN DIAMETER.  

THE STORM WAS STATIONARY.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN DENVER.

LAT...LON 3993 1t0462 3966 10481 3972 10492 3983 10489

BARJENBRUCH

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 19, 11:15 AM MDT, 5 hours 24 minutes before
COZ030-032>050-200600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT SAT JUL 19 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: MOISTURE HAS INCREASED ACROSS THE AREA AT ALL LEVELS.  IN
ADDITION A COUPLE OF UPPER LEVEL DISTURBANCES WILL ENHANCE
THUNDERSTORM ACTIVITY ACROSS THE AREA.  ONE IS MOVING NORTH ALONG
THE FRONT RANGE...LOCATED WEST OF COLORADO SPRINGS THIS MORNING.
ANOTHER IS APPROACHING FROM THE WEST.  FINALLY...A LOW LEVEL
BOUNDARY IS PRESENT FROM WEST OF LIMON NORTH ACROSS EASTERN ARAPAHOE
AND ADAMS COUNTIES...SEPARATING NORTHWEST WINDS TO THE WEST FROM
SOUTHEAST FLOW.  THUNDERSTORMS ARE ALREADY FORMING NORTHWEST OF
GREELEY AND WILL BECOME MORE WIDESPREAD THROUGH THE AFTERNOON.
WINDS ALOFT ARE LIGHT...SO WELL-ORGANIZED STORMS ARE NOT
ANTICIPATED.  THE MAIN THREAT IS EXPECTED TO BE LOCALLY HEAVY
RAINS.  HAIL IS ALSO POSSIBLE WITH SOME OF THE STRONGER STORMS BUT
SHOULD GENERALLY REMAIN BELOW SEVERE LEVELS.

AT THIS TIME SPOTTER ACTIVATION IS NOT ANTICIPATED BUT RAINFALL
REPORTS WOULD BE APPRECIATED.   SZOKE
Special weather statement, Jul 19, 12:46 PM MDT, 3 hours 53 minutes before
COZ038-191915-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1246 PM MDT SAT JUL 19 1997

...THUNDERSTORM IN NORTHWESTERN WELD COUNTY...

AT 1246 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM 3 MILES SOUTHEAST OF CARR...OR ABOUT 23 MILES NORTHEAST
OF FORT COLLINS. THIS STORM HAS A HISTORY OF PRODUCING PEA TO MARBLE
SIZE HAIL.

THE STORM WAS MOVING NORTH AT 15 MILES PER HOUR.

PERSONS IN OR NEAR CARR...NATURAL FORT REST AREA AND ROCKPORT
SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE
OF SAFETY IF BAD WEATHER APPROACHES.

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.

HERRALD
Special weather statement, Jul 19, 12:49 PM MDT, 3 hours 50 minutes before
COZ038-191915-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1246 PM MDT SAT JUL 19 1997

...THUNDERSTORM IN NORTHWESTERN WELD COUNTY...

AT 1246 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM 3 MILES SOUTHEAST OF CARR...OR ABOUT 23 MILES NORTHEAST
OF FORT COLLINS. THIS STORM HAS A HISTORY OF PRODUCING PEA TO MARBLE
SIZE HAIL.

THE STORM WAS MOVING NORTH AT 15 MILES PER HOUR.

PERSONS IN OR NEAR CARR...NATURAL FORT REST AREA AND ROCKPORT
SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE
OF SAFETY IF BAD WEATHER APPROACHES.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CRO4SS 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.

HERRALD
Special weather statement, Jul 19, 2:55 PM MDT, 1 hour 44 minutes before
COZ040-042-045-192200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
255 PM MDT SAT JUL 19 1997

...WEAK SHORT-LIVED TORNADOES MAY BE DEVELOPING NORTH AND EAST OF
DENVER...

AT 255 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
QUICKLY DEVELOPING THUNDERSTORMS OVER SOUTHEAST WELD COUNTY.  THESE
STORMS WERE DEVELOPING ON COLLIDING THUNDERSTORM OUTFLOW
BOUNDARIES.  AS STORMS CONTINUE TO DEVELOP ALONG THE BOUNDARIES...
THERE IS POTENTIAL THAT THESE STORMS COULD PRODUCE WEAK SHORT-LIVED
TORNADOES.

PERSONS BETWEEN PROSPECT VALLEY IN SOUTHEAST WELD COUNTY AND DENVER
INTERNATIONAL AIRPORT SHOULD BE ON THE LOOKOUT FOR DANGEROUS WEATHER
CONDITIONS.  IF THREATENING WEATHER APPROACHES...TAKE SHELTER IN A
REINFORCED BUILDING.  STAY AWAY FROM WINDOWS.

BARJENBRUCH
Special weather statement, Jul 19, 2:56 PM MDT, 1 hour 43 minutes before
COZ040-042-045-192200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
255 PM MDT SAT JUL 19 1997

...WEAK SHORT-LIVED TORNADOES MAY BE DEVELOPING NORTH AND EAST OF
DENVER...

AT 255 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
QUICKLY DEVELOPING THUNDERSTORMS OVER SOUTHEAST WELD COUNTY.  THESE
STORMS WERE DEVELOPING ON COLLIDING THUNDERSTORM OUTFLOW
BOUNDARIES.  AS STORMS CONTINUE TO DEVELOP ALONG THE BOUNDARIES...
THERE IS POTENTIAL THAT THESE STORMS COULD PRODUCE WEAK SHORT-LIVED
TORNADOES.

PERSONS BETWEEN PROSPECT VALLEY IN SOUTHEAST WELD COUNTY AND DENVER
INTERNATIONAL AIRPORT SHOULD BE ON THE LOOKOUT FOR DANGEROUS WEATHER
CONDITIONS.  IF THREATvENING WEATHER APPROACHES...TAKE SHELTER IN A
REINFORCED BUILDING.  STAY AWAY FROM WINDOWS.

BARJENBRUCH

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 19, 1:06 PM MDTSevere Thunderstorm WarningBOUWeld24 min
Jul 19, 1:35 PM MDTSevere Thunderstorm WarningBOUWeld30 min
Jul 19, 5:15 PM MDTFlash Flood WarningBOUAdams, Arapahoe, Denver90 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.