Alert archive / Wyoming / Flash Flood Warnings in 2000

Flash Flood Warning 3, NWS Cheyenne, WY

May 17, 2000Platte County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at May 17, 2000, 10:20 PM MDT for Platte County, Wyoming. It was in force for 18 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
May 17, 2000, 10:20 PM MDT (04:20 UTC)
Expired
May 18, 2000, 4:00 PM MDT
In force
18 hr
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Platte County, WY

The radar

The Cheyenne radar (KCYS), 110 km from the middle of the area, began a volume at 04:22 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

Rapid City, SD (KUNR), launched 00:00Z, 4.3 hours before the alert went out and 274 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, Rapid City, SD at 00:00Z on 2000-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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, Rapid City, SD at 00:00Z on 2000-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 222 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
10 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
555 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
222 m²/s²
0-3 km storm-relative helicity
262 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 
WGUS55 KCYS 180420
FFWCYS
WYC031-181000-

BULLETIN...IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
1020 PM MDT WED MAY 17 2000

...FLASH FLOOD WARNING FOR ROCK CREEK UNTIL 4 AM...

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING FOR 
ROCK CREEK IN PLATTE COUNTY EAST OF WHEATLAND.

HEAVY RAINS OVER THE LAST 18 HOURS HAVE CAUSED MANY STREAMS AND 
CREEKS TO RUN BANKFULL OR HIGHER.

PLATTE COUNTY OFFICIALS REPORT OAK PARK MOBILE HOME PARK WILL BE 
EVACUATED.  WATER DISTRICT OFFICALS ARE DIVERTING WATER AWAY FROM 
ROCK CREEK BUT IT WILL BE SEVERAL HOURS BEFORE THIS LESSONS THE 
FLOODING PROBLEM.

THIS IS A DANGEROUS SITUATION!  IF YOU LIVE ALPONG ROCK CREEK GO 
TO HIGHER GROUND NOW!

REMEMBER NEVER DRIVE INTO FLOODED AREAS.  BE ESPECIALLY CAUTIOUS 
DURING HOURS OF DARKNESS WHEN FLOODED AREAS AND WASHED OUT ROADS ARE 
MORE DIFFICULT TO SEE.

GRIFFITH
WCJIN-WYSE

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 7:55 PM MDTFlash Flood WarningCYSWeston3 hr
May 17, 9:44 PM MDTFlash Flood WarningCYSConverse16 hr

Nearby

Flash Flood Warnings in Wyoming, 2000Every flash flood warning in 2000

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.