Alert archive / Wyoming / Flash Flood Warnings in 1998

Flash Flood Warning 1, NWS Cheyenne, WY

July 1, 1998Converse County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jul 1, 1998, 9:22 PM MDT for Converse County, Wyoming. It was in force for 6 hr. 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 1, 1998, 9:22 PM MDT (03:22 UTC)
Expired
Jul 2, 1998, 3:00 AM MDT
In force
6 hr
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Converse County, WY

The nearest sounding before it

Riverton, WY (KRIW), launched 00:00Z, 3.4 hours before the alert went out and 235 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, Riverton, WY at 00:00Z on 1998-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 228 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, Riverton, WY at 00:00Z on 1998-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.19395878Sfc1 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
228 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
3425 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCYS 020321
FFWCYS
WYC009-020900-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
922 PM MDT WED JUL 1 1998

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN CONVERSE COUNTY IN EAST CENTRAL WYOMING

* UNTIL 300 AM MDT

* AT 915 PM... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
 THUNDERSTORMS WITH EXTREMELY HEAVY RAINFALL MOVING THROUGH
 NORTHERN CONVERSE COUNTY.

* THESE THUNDERSTORMS HAVE DROPPED EXTREMELY HEAVY RAINS...IN EXCESS
 OF 3 TO 4 INCHES...IN NORTHERN CONVERSE COUNTY BETWEEN 30 AND 50
 MILES TO THE NORTH AND NORTHWEST OF DOUGLAS OR FROM NEAR BILL TO 25
 MILES WEST OF BILL.  STRONG THUNDERSTORMS ARE EXPECTED TO DROP
 ANOTHER 2 TO 3 INCHES OVER THE SAME AREAS BY 1030.

IF YOU LIVE IN A LOW LYING AREA IN NORTHERN CONVERSE COUNTY...MOVE TO
HIGHER GROUND.  WATER MAY RISE OVER HIGHWAY 59 NORTH OF BILL AND OTHER
ROADS IN NORTHERN CONVERSE COUNTY. n NEVER DRIVE THROUGH WATER COVERED
ROADS.

WCJIN-WYNE

DMM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 7:10 PM MDTSevere Thunderstorm WarningCYSConverse60 min
Jul 1, 7:59 PM MDTTornado WarningCYSConverse31 min
Jul 1, 8:30 PM MDTSevere Thunderstorm WarningCYSConverse60 min
Jul 1, 9:33 PM MDTSevere Thunderstorm WarningCYSConverse47 min
Jul 1, 10:01 PM MDTSevere Thunderstorm WarningCYSNiobrara44 min
Jul 2, 3:47 PM MDTTornado WarningCYSAlbany28 min
Jul 2, 3:53 PM MDTSevere Thunderstorm WarningCYSAlbany47 min
Jul 2, 4:35 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jul 2, 4:54 PM MDTSevere Thunderstorm WarningCYSLaramie41 min
Jul 2, 5:31 PM MDTSevere Thunderstorm WarningCYSLaramie49 min
Jul 2, 5:51 PM MDTSevere Thunderstorm WarningCYSGoshen49 min

Nearby

Flash Flood Warnings in Wyoming, 1998Every flash flood warning in 1998

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.