Alert archive / Wyoming / Flash Flood Warnings in 2007

Flash Flood Warning 21, NWS Riverton, WY

August 18, 2007Park County, Wyoming

NWS Riverton, WY issued this flash flood warning at Aug 18, 2007, 2:13 PM MDT for Park County, Wyoming. It was in force for 3 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 18, 2007, 2:13 PM MDT (20:13 UTC)
Expired: Aug 18, 2007, 5:15 PM MDT
In force: 3 hr
Issued by: NWS Riverton, WY
Area: Whole counties

County Park County, WY

The radar

The Billings radar (KBLX), 167 km from the middle of the area, began a volume at 20:14 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 12:00Z, 8.2 hours before the alert went out and 187 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1841 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 107 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

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

000 
WGUS55 KRIW 182016
FFWRIW
WYC029-182315-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
213 PM MDT SAT AUG 18 2007

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL PARK COUNTY IN NORTHWEST WYOMING...

* UNTIL 515 PM MDT

* AT 209 PM MDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING   
  FROM A THUNDERSTORM OVER THE WARNED AREA. IN ADDITION A MUDSLIDE   
  HAS BEEN REPORTED NEAR MORMON CREEK ALONG HIGHWAY 20. ADDITIONAL   
  MUDSLIDES ARE POSSIBLE THIS AFTERNOON.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HWY
  14/16/20 MILE MARKER 10...SYLVAN PASS...SYLVAN LAKE...EAST ENTRANCE
  AND PAHASKA

ADDITIONAL RAINFALL AMOUNTS OF ONE INCH ARE POSSIBLE IN THE WARNED 
AREA UNTIL LATE AFTERNOON.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
DEBRIS FLOWS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY AUTOMOBILE.

REPORT FLOODING TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT
1-800-211-1448.

LAT...LON 4431 11015 4438 10977 4471 10984 4455 11025

$$

LYNOTT

1 follow-up statement

000 
WGUS75 KRIW 182128
FFSRIW

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
322 PM MDT SAT AUG 18 2007

WYC029-182315-
PARK WY-
322 PM MDT SAT AUG 18 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM MDT FOR
CENTRAL PARK COUNTY...

AT 316 PM MDT...LIGHT RAIN CONTINUED TO FALL OVER THE WARNED AREA.
STREAMS AND RIVERS SUCH AS MORMON CREEK WILL NEED TO BE MONITORED.
LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PAHASKA...
SYLVAN LAKE AND EAST ENTRANCE.

ADDITIONAL RAINFALL AMOUNTS OF ONE INCH ARE POSSIBLE LATER THIS 
AFTERNOON AS ADDITIONAL THUNDERSTORMS MOVE INTO THE AREA. 
THEREFORE...BE AWARE OF SUDDEN RISES ON CREEKS AND STREAMS...AS WELL 
AS MUDSLIDES NEAR STEEP TERRAIN. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
DEBRIS FLOWS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY AUTOMOBILE.

REPORT FLOODING OR MUDSLIDES TO THE NATIONAL WEATHER SERVICE OFFICE 
IN RIVERTON AT 1-800-211-1448.

LAT...LON 4431 11015 4438 10977 4471 10984 4455 11025

$$

LYNOTT

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 4:30 PM MDT	Flash Flood Warning	RIW	Teton	4 hr
Aug 18, 5:03 PM MDT	Fire Weather Watch	RIW	Fremont, Hot Springs, Lincoln, Park, Sublette, Sweetwater and 2 more	10 hr

Nearby

Flash Flood Warnings in Wyoming, 2007 Every flash flood warning in 2007

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.