Alert archive / Nebraska / Flash Flood Warnings in 2015

Flash Flood Warning 21, NWS Cheyenne, WY

August 11, 2015Cheyenne County, Kimball County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Aug 11, 2015, 12:38 AM MDT for Cheyenne County, Kimball County, Nebraska. It was in force for 7 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 11, 2015, 12:38 AM MDT (06:38 UTC)
Expired: Aug 11, 2015, 7:30 AM MDT
In force: 7 hr
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Flood severity: None

Counties Cheyenne County, NE, Kimball County, NE

The radar

The Cheyenne radar (KCYS), 115 km from the middle of the area, began a volume at 06:38 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 11, 6:20 AM MDT	FLASH FLOOD	2 W Dix, NE	LAW ENFORCEMENT AND UNION PACIFIC REPORTED COUNTY ROAD 55...AND THE RAILROAD NEAR HIGHWAY 30 HAS BEEN WASHED OUT WEST OF DIX.
Aug 11, 6:20 AM MDT	FLASH FLOOD	3 E Kimball, NE	LAW ENFORCEMENT REPORTED COUNTY ROAD 47 NEAR HIGHWAY 30 IS WASHED OUT BETWEEN KIMBALL AND DIX.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 6.6 hours before the alert went out and 151 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: 40 J/kg
Mixed-layer CIN: -230 J/kg
Mixed-layer LCL: 1869 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 11 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.

492 
WGUS55 KCYS 110638
FFWCYS
NEC033-105-111330-
/O.NEW.KCYS.FF.W.0021.150811T0638Z-150811T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
1238 AM MDT TUE AUG 11 2015

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL KIMBALL COUNTY IN THE PANHANDLE OF NEBRASKA...
  WEST CENTRAL CHEYENNE COUNTY IN THE PANHANDLE OF NEBRASKA...

* UNTIL 730 AM MDT TUESDAY
    
* AT 1229 AM MDT...LAW ENFORCEMENT IN KIMBALL COUNTY REPORTED 
  FLOODING ASSOCIATED WITH HEAVY RAIN ACROSS THE WARNED AREA. RADAR 
  ESTIMATES BETWEEN THREE TO SIX INCHES OF RAIN HAVE ALREADY FALLEN 
  OVER EASTERN KIMBALL COUNTY AND EXTREME WESTERN CHEYENNE COUNTY 
  TONIGHT. 
  
ADDITIONAL RAINFALL AMOUNTS OF TWO TO THREE INCHES ARE POSSIBLE IN 
THE WARNED AREA.

IN ADDITION...FLOOD WATERS ARE POSSIBLE ALONG LODGEPOLE CREEK 
BETWEEN KIMBALL AND POTTER THIS MORNING DUE TO THE HEAVY RAINFALL 
UPSTREAM. THE FLOOD CREST IS EXPECTED TO REACH DIX BETWEEN 2 AM MDT 
AND 4 AM MDT AND POTTER BETWEEN 6 AM MDT AND 8 AM MDT THIS MORNING.

THIS INCLUDES INTERSTATE 80 IN NEBRASKA BETWEEN MILE MARKERS 20 AND
41.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 4130 10328 4112 10327 4109 10368 4128 10368

$$

TJT

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 6:48 PM MDT	Special Weather Statement	CYS	Banner	42 min
Aug 10, 7:54 PM MDT	Special Weather Statement	CYS	Banner	51 min
Aug 10, 8:01 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Kimball	59 min
Aug 10, 9:02 PM MDT	Special Weather Statement	CYS	Kimball	43 min
Aug 10, 9:04 PM MDT	Special Weather Statement	CYS	Kimball	41 min
Aug 10, 9:47 PM MDT	Flash Flood Warning	CYS	Kimball	3 hr
Aug 10, 10:42 PM MDT	Special Weather Statement	CYS	Kimball	48 min
Aug 11, 1:57 AM MDT	Flash Flood Warning	CYS	Cheyenne	6 hr
Aug 11, 7:51 AM MDT	Areal Flood Warning	CYS	Kimball	6 hr

Nearby

Flash Flood Warnings in Nebraska, 2015 Every flash flood warning in 2015

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.