Alert archive / Wyoming / Flash Flood Warnings in 1997

Flash Flood Warning 11, NWS Cheyenne, WY

August 16, 1997Laramie County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Aug 16, 1997, 8:09 PM MDT for Laramie County, Wyoming. It was in force for 56 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
Aug 16, 1997, 8:09 PM MDT (02:09 UTC)
Expired
Aug 16, 1997, 9:05 PM MDT
In force
56 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 20 km from the middle of the area, began a volume at 02:12 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 00:00Z, 2.2 hours before the alert went out and 202 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 00:00Z on 1997-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1611 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 00:00Z on 1997-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
1611 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1576 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
-15 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 KCYS 170218 COR
FFWCYS
WYC021-170305-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTED FOR EXPIRATION TIME OF 905 PM.
NATIONAL WEATHER SERVICE CHEYENNE WY
809 PM MDT SAT AUG 16 1997

* FLASH FLOOD WARNING FOR
  SOUTHWESTERN LARAMIE COUNTY IN SOUTHEASTERN WYOMING

* UNTIL 905 PM MDT

* SOME LOCATIONS AFFECTED
  CHEYENNE

  *CAUSE AND EFFECT
  A THUNDERSTORM MOVING INTO CHEYENNE MAY CAUSE ANOTHER INCH OF
  RAINFALL OVER THE CITY.  FLOODING OF LOW AREAS IS AGAIN LIKELY
  UNTIL 905 PM.

DO NOT ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  THE ROADBED MAY BE WASHED OUT.

WCJIN-WYSE.

BAKER/PAL

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 6:03 PM MDTSevere Thunderstorm WarningCYSLaramie62 min
Aug 16, 6:14 PM MDTFlash Flood WarningCYSLaramie46 min
Aug 16, 6:14 PM MDTSevere Thunderstorm WarningCYSLaramie46 min
Aug 16, 6:51 PM MDTFlash Flood WarningCYSLaramie59 min
Aug 16, 6:51 PM MDTSevere Thunderstorm WarningCYSLaramie59 min

Nearby

Flash Flood Warnings in Wyoming, 1997Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.