Alert archive / Colorado / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 207, NWS Denver/Boulder, CO

July 30, 1996Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 30, 1996, 2:59 PM MDT for Washington County, Colorado. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 30, 1996, 2:59 PM MDT (20:59 UTC)
Expired
Jul 30, 1996, 3:40 PM MDT
In force
41 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Washington County, CO

The radar

The Denver radar (KFTG), 117 km from the middle of the area, began a volume at 20:59 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 9.0 hours before the alert went out and 11 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 1996-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 1996-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 square meters per square second.193958Sfc1 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
11 J/kg
Mixed-layer CIN
-159 J/kg
Mixed-layer LCL
1187 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 30, 11:34 AM MDT, 3 hours 25 minutes before
COZ030-032>050-300600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER COLORADO
1140 AM MDT MON JULY 30 1996

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:  ABUNDANT MOISTURE WILL BE AVAILABLE TODAY...ALONG WITH
SOUTHEASTERLY WINDS NEAR THE GROUND...TURNING TO NORTHWESTERLY ALOFT
WHICH WILL SLOWLY INCREASE LATER TODAY.  ABUNDANT SUNSHINE WILL
ALLOW FOR THE SCATTERED THUNDERSTORMS TO BREW FIRST OVER THE
NORTHERN FOOTHILLS AND DEVELOP TO THE URBAN CORRIDOR EARLY THIS
AFTERNOON.  EASTERN COLORADO HAS BEEN UNDER A BLANKET OF CLOUDS
EARLY THIS MORNING...SO IT WILL BE MORE STABLE...THUNDERSTORMS THERE
WILL MOST LIKELY WAIT UNTIL LATE AFTERNOON TO DEVELOP...BUT WILL
CONTINUE LATE INTO THE EVENING.

THE MAIN THREAT FOR TODAY WILL BE LOCALLY HEAVY RAIN...AS
THUNDERSTORMS WILL MOVE SLOWLY SOUTHEASTWARD.  THERE MAY BE A FEW
WEAK TORNADOES WITH STORMS IN THE NORTHEASXT DUE TO THE WEAK WINDS
TURNING COUNTER CLOCKWISE WITH HEIGHT.

SPOTTER ACTIVATION MAY BE NEEDED AFTER 2PM.

RTG
Special weather statement, Jul 30, 1:13 PM MDT, 1 hour 46 minutes before
COZ049-292000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
112PM MDT TUE JUL 30 1996

...VERY HEAVY RAIN IN NORTHWEST WASHINGTON COUNTY...

AT 1PM NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A VERY SLOW
MOVING THUNDERSTORMS SOUTHEAST OF PREWITT RESERVOIR THAT WAS MOVING
VERY SLOWLY TO THE SOUTH.  RAINFALL RATES WITH THIS STORM HAVE BEEN
1.5 TO 2 INCHES PER HOUR.  THE STORM WAS ALSO LIKELY PRODUCING SMALL
HAIL.

RESIDENTS OF NORTHWESTERN WASHINGTON COUNTY BETWEN AKRON AND THE
PREWITT RESERVOIR WILL CONTINUE TO HAVE VERY HEAVY RAIN THROUGH 2PM.
SMALL STREAMS AND DITCHES WILL REACH BANKFUL.  DIRT ROADS WILL
BECOME TREACHEROUS.  ANYONE TRAVELLING IN NORTHWEST WASHINGTON
COUNTY SHOULD CONSIDER DELAYING TRAVEL UNTIL LATER IN THE
AFTERNOON.

RTG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 2:29 PM MDTSevere Thunderstorm WarningBOUWashington31 min
Jul 30, 3:17 PM MDTTornado WarningBOUWashington43 min
Jul 30, 3:43 PM MDTTornado WarningBOULincoln, Washington32 min
Jul 30, 4:16 PM MDTTornado WarningBOULincoln29 min
Jul 30, 4:45 PM MDTSevere Thunderstorm WarningBOULincoln30 min
Jul 30, 5:12 PM MDTSevere Thunderstorm WarningBOULincoln38 min

Nearby

Severe Thunderstorm Warnings in Colorado, 1996Every severe thunderstorm warning in 1996

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.