Alert archive / Wyoming / Flash Flood Warnings in 2011
Flash Flood Warning 21, NWS Cheyenne, WY
NWS Cheyenne, WY issued this flash flood warning at Aug 3, 2011, 3:08 PM MDT for Laramie County, Wyoming. It was in force for 3 hr. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 3, 2011, 3:08 PM MDT (21:08 UTC)
- Expired
- Aug 3, 2011, 5:41 PM MDT
- In force
- 3 hr
- Issued by
- NWS Cheyenne, WY
- Area
- Storm-based polygon
- Flood severity
- None
County Laramie County, WY
The radar
The Cheyenne radar (KCYS), 22 km from the middle of the area, began a volume at 21:07 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 3, 5:33 PM MDT | FLOOD | Cheyenne, WY | INTERSECTION OF PERSHING AND DILLON WATER 1 TO 2 FEET DEEP |
| Aug 3, 5:33 PM MDT | FLASH FLOOD | Cheyenne, WY | INTERSECTION OF PERSHING AND DILLON WATER 1 TO 2 FEET DEEP |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 9.1 hours before the alert went out and 198 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.
- Mixed-layer CAPE
- 15 J/kg
- Mixed-layer CIN
- -54 J/kg
- Mixed-layer LCL
- 1190 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- -14 m²/s²
- 0-3 km storm-relative helicity
- 4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
147 WGUS55 KCYS 032108 FFWCYS WYC021-040300- /O.NEW.KCYS.FF.W.0021.110803T2108Z-110804T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE CHEYENNE WY 308 PM MDT WED AUG 3 2011 THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A * FLASH FLOOD WARNING FOR... CENTRAL LARAMIE COUNTY IN SOUTHEAST WYOMING... * UNTIL 900 PM MDT * AT 307 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR ESTIMATES OF NEARLY 2 INCHES OF RAIN ARE INDICATED. * RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... CHEYENNE...NORTH CHEYENNE AND WHITAKER. PRECAUTIONARY/PREPAREDNESS ACTIONS... DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. && LAT...LON 4142 10444 4106 10448 4116 10484 4145 10495 $$ GRIFFITH
2 follow-up statements
194 WGUS75 KCYS 032309 FFSCYS FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 509 PM MDT WED AUG 3 2011 WYC021-040300- /O.CON.KCYS.FF.W.0021.000000T0000Z-110804T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ LARAMIE WY- 509 PM MDT WED AUG 3 2011 ...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL LARAMIE COUNTY UNTIL 900 PM MDT... AT 508 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. DOPPLER RADAR ESTIMATES 2 TO 3 INCHES OF RAIN NORTH OF CHEYENNE HAS FALLEN. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...NORTH CHEYENNE AND WHITAKER. 0.72 INCHES RAIN HAS BEEN RECORDED AT THE CHEYENNE AIRPORT. PRECAUTIONARY/PREPAREDNESS ACTIONS... DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. && LAT...LON 4142 10444 4106 10448 4116 10484 4145 10495 $$ GRIFFITH
961 WGUS75 KCYS 032341 FFSCYS FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 541 PM MDT WED AUG 3 2011 WYC021-032356- /O.CAN.KCYS.FF.W.0021.000000T0000Z-110804T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ LARAMIE WY- 541 PM MDT WED AUG 3 2011 ...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL LARAMIE COUNTY IS CANCELLED... EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED... PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY. LAT...LON 4142 10444 4106 10448 4116 10484 4145 10495 $$ GRIFFITH
Nearby
Flash Flood Warnings in Wyoming, 2011Every flash flood warning in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.