Alert archive / Nebraska / Flash Flood Warnings in 2017

Flash Flood Warning 4, NWS Cheyenne, WY

July 19, 2017Cheyenne County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Jul 19, 2017, 7:31 PM MDT for Cheyenne County, Nebraska. 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: Jul 19, 2017, 7:31 PM MDT (01:31 UTC)
Expired: Jul 19, 2017, 10:30 PM MDT
In force: 3 hr
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Flood severity: None

County Cheyenne County, NE

The radar

The Cheyenne radar (KCYS), 167 km from the middle of the area, began a volume at 01:34 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
Jul 19, 8:02 PM MDT	FLASH FLOOD	3 E Gurley, NE	REPORTS OF BASEMENT FLOODING AND FLOODING IN OUT-BUILDINGS ON PROPERTY 3 MILES EAST OF GURLEY NEBRASKA. 2.25 INCHES OF RAIN MEASURED IN 90 MINUTES.
Jul 19, 9:55 PM MDT	HEAVY RAIN 4.05	7 Ene Gurley, NE

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, 1.5 hours before the alert went out and 169 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: 3997 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 17 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

647 
WGUS55 KCYS 200131
FFWCYS
NEC033-200430-
/O.NEW.KCYS.FF.W.0004.170720T0131Z-170720T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Cheyenne WY
731 PM MDT WED JUL 19 2017

The National Weather Service in Cheyenne has issued a

* Flash Flood Warning for...
  Northeastern Cheyenne County in the Panhandle of Nebraska...

* Until 1030 PM MDT

* At 730 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding has been 
  reported 3 miles east of Gurley.

* Some locations that will experience flooding include...
  Dalton and Gurley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4143 10272 4126 10273 4126 10297 4143 10298

$$

Emanuel

1 follow-up statement

843 
WGUS75 KCYS 200347
FFSCYS

Flash Flood Statement
National Weather Service Cheyenne WY
947 PM MDT WED JUL 19 2017

NEC033-200355-
/O.CAN.KCYS.FF.W.0004.000000T0000Z-170720T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cheyenne NE-
947 PM MDT WED JUL 19 2017

...THE FLASH FLOOD WARNING FOR NORTHEASTERN CHEYENNE COUNTY IS
CANCELLED...

The heavy rain has ended and flood waters have receded. Flooding is 
no longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 4143 10272 4126 10273 4126 10297 4143 10298

$$

Emanuel

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 6:19 PM MDT	Special Weather Statement	CYS	Cheyenne	41 min
Jul 19, 6:28 PM MDT	Special Weather Statement	CYS	Cheyenne	47 min
Jul 19, 6:41 PM MDT	Areal Flood Advisory	CYS	Cheyenne	2 hr
Jul 19, 7:17 PM MDT	Special Weather Statement	CYS	Cheyenne	43 min
Jul 19, 8:50 PM MDT	Special Weather Statement	CYS	Scotts Bluff	40 min
Jul 19, 10:05 PM MDT	Special Weather Statement	CYS	Scotts Bluff	40 min

Nearby

Flash Flood Warnings in Nebraska, 2017 Every flash flood warning in 2017

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.