Alert archive / Wyoming / Flash Flood Warnings in 2002

Flash Flood Warning 3, NWS Riverton, WY

August 27, 2002Johnson County, Wyoming

NWS Riverton, WY issued this flash flood warning at Aug 27, 2002, 4:00 AM MDT for Johnson County, Wyoming. It was in force for 4 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: Aug 27, 2002, 4:00 AM MDT (10:00 UTC)
Expired: Aug 27, 2002, 8:00 AM MDT
In force: 4 hr
Issued by: NWS Riverton, WY
Area: Whole counties

County Johnson County, WY

The radar

The Riverton/Lander radar (KRIW), 187 km from the middle of the area, began a volume at 10:01 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

Riverton, WY (KRIW), launched 00:00Z, 10.0 hours before the alert went out and 182 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 172 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 3663 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 165 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

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

000 
WGUS55 KRIW 271000
FFWRIW
WYC019-271400-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
359 AM MDT TUE AUG 27 2002

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN JOHNSON COUNTY IN NORTH CENTRAL WYOMING

* UNTIL 800 AM MDT

* AT 355 AM MDT...DOPPLER RADAR CONTINUED TO INDICATE EXCESSIVE 
RAINFALL OVER SOUTHERN JOHNSON COUNTY...OR ABOUT 10 MILES SOUTH OF 
KAYCEE. AT 355 AM...THE JOHNSON COUNTY SHERIFF REPORTED FLOODING IN 
KAYCEE. AROUND 230 AM MDT...THE KAYCEE FIRE DEPARTMENT REPORTED 
FLASH FLOODING ALONG BARNUM ROAD BETWEEN KAYCEE AND BARNUM. 

DOPPLER RADAR HAS INDICATED AS MUCH AS 7 INCHES OF RAIN ABOUT 10 
MILES SOUTH OF KAYCEE IN AND NEAR LONE BEAR ROAD. DOPPLER RADAR 
INDICATED THE ASSOCIATED STORM MOVING NORTHEAST AT 20 MPH. 
WIDESPREAD MODERATE TO HEAVY RAINFALL CONTINUED OVER SOUTHERN 
JOHNSON AND NORTHWEST NATRONA COUNTY.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF
STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES...AS WELL AS FARMLAND 
ALONG THE BANKS OF STREAMS ACROSS MUCH OF SOUTHERN JOHNSON COUNTY.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IT IS NEARLY IMPOSSIBLE AT NIGHT TO TELL THE
DEPTH OF WATER ON ROADWAYS. NEVER DRIVE THROUGH WATER OF UNKNOWN 
DEPTH. 

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
RIVERTON.


$$
LAT...LON 4374 10704 4354 10698 4355 10614 4387 10626

SKRBAC

WCJIN-WYNE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 27, 1:05 AM MDT	Flash Flood Warning	RIW	Johnson	3 hr
Aug 27, 3:04 AM MDT	Severe Thunderstorm Warning	RIW	Natrona	56 min

Nearby

Flash Flood Warnings in Wyoming, 2002 Every flash flood warning in 2002

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.