Alert archive / Wyoming / Flash Flood Warnings in 2017

Flash Flood Warning 2, NWS Cheyenne, WY

June 5, 2017Converse County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jun 5, 2017, 5:11 PM MDT for Converse 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: Jun 5, 2017, 5:11 PM MDT (23:11 UTC)
Expired: Jun 5, 2017, 8:15 PM MDT
In force: 3 hr
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Flood severity: None

County Converse County, WY

The radar

The Cheyenne radar (KCYS), 212 km from the middle of the area, began a volume at 23:11 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
Jun 5, 6:40 PM MDT	HEAVY RAIN 0	12 Ne Glenrock, WY	CONVERSE COUNTY DEPUTIES REPORT NO WATER RUNNING IN LITTLE SAND CREEK. HOWEVER...CONSIDERABLE STANDING WATER NEAR MILE MARKER 14 AND 15 ALONG BOTH SIDES OF STATE HIGHWAY 95. DUAL POL RADAR ESTIMATES 3 TO 4 INCHES OF RAIN IN THIS AREA FROM EARLIER THUNDERSTORMS
Jun 5, 6:40 PM MDT	HEAVY RAIN 0	12 Ne Glenrock, WY	CONVERSE COUNTY DEPUTIES REPORT NO WATER RUNNING IN LITTLE SAND CREEK. HOWEVER...CONSIDERABLE STANDING WATER NEAR MILE MARKER 15 AND 16 ALONG BOTH SIDES OF STATE HIGHWAY 95. DUAL POL RADAR ESTIMATES 3 TO 4 INCHES OF RAIN IN THIS AREA FROM EARLIER THUNDERSTORMS

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

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 11.2 hours before the alert went out and 224 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: 2763 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

898 
WGUS55 KCYS 052311
FFWCYS
WYC009-060215-
/O.NEW.KCYS.FF.W.0002.170605T2311Z-170606T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Cheyenne WY
511 PM MDT MON JUN 5 2017

The National Weather Service in Cheyenne has issued a

* Flash Flood Warning for...
  West central Converse County in east central Wyoming...

* Until 815 PM MDT

* At 508 PM MDT, Doppler radar indicated slow moving thunderstorms 
  producing very heavy rain across the warned area. Up to two inches 
  of rain have already fallen, with an additional inch or two 
  possible. Flash flooding is expected to begin shortly.

This includes areas along Little Sand Creek east of Glenrock and 
Rolling Hills. This may impact portions of Highway 95 and Tank Farm 
Road near the Little Sand Creek drainage. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 4308 10556 4276 10545 4282 10580 4305 10585

$$

Hammer

1 follow-up statement

045 
WGUS75 KCYS 060054
FFSCYS

Flash Flood Statement
National Weather Service Cheyenne WY
654 PM MDT MON JUN 5 2017

WYC009-060103-
/O.CAN.KCYS.FF.W.0002.000000T0000Z-170606T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Converse WY-
654 PM MDT MON JUN 5 2017

...THE FLASH FLOOD WARNING FOR WEST CENTRAL CONVERSE COUNTY IS
CANCELLED...

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

LAT...LON 4308 10556 4276 10545 4282 10580 4305 10585

$$

Hammer

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 5, 12:04 PM MDT	Special Weather Statement	CYS	Laramie	26 min
Jun 5, 2:25 PM MDT	Special Weather Statement	CYS	Platte	50 min
Jun 5, 3:18 PM MDT	Special Weather Statement	CYS	Laramie	42 min
Jun 5, 3:27 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie, Platte	33 min
Jun 5, 4:12 PM MDT	Special Weather Statement	CYS	Albany	48 min
Jun 5, 4:33 PM MDT	Special Weather Statement	CYS	Converse	27 min
Jun 5, 4:37 PM MDT	Severe Thunderstorm Warning	CYS	Converse	23 min

Nearby

Flash Flood Warnings in Wyoming, 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.