Alert archive / Wyoming / Flash Flood Warnings in 2018

Flash Flood Warning 9, NWS Cheyenne, WY

July 12, 2018Albany County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jul 12, 2018, 12:42 PM MDT for Albany County, Wyoming. It was in force for 3 hr. 1 report 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 12, 2018, 12:42 PM MDT (18:42 UTC)
Expired
Jul 12, 2018, 3:30 PM MDT
In force
3 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

County Albany County, WY

The radar

The Cheyenne radar (KCYS), 108 km from the middle of the area, began a volume at 18:44 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

TimeReportWhereRemark
Jul 12, 1:45 PM MDTFLASH FLOOD1 Sse Woods Landing, WYREPORT OF MUD AND DEBRIS ACROSS HIGHWAY 230 NEAR WOODS LANDING.

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 12:00Z, 6.7 hours before the alert went out and 276 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-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2018-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2018-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
6 J/kg
Mixed-layer CIN
-334 J/kg
Mixed-layer LCL
1617 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

816 
WGUS55 KCYS 121842
FFWCYS
WYC001-122130-
/O.NEW.KCYS.FF.W.0009.180712T1842Z-180712T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Cheyenne WY
1242 PM MDT THU JUL 12 2018

The National Weather Service in Cheyenne has issued a

* Flash Flood Warning for...
  Southern Albany County in southeastern Wyoming...

* Until 330 PM MDT.

* At 1236 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. This includes the Badger Creek 
  Fire Burn Scar. Up to one inch of rain has already fallen. Flash 
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  The Badger Creek Fire Burn Scar, Boswell Creek Campground, Woods 
  Landing, Miller Lake Campground, Evans Creek Campground and Woods 
  Landing-Jelm.

Excessive rainfall over the Badger Creek burn scar will result in 
the possibility of debris flows moving through the Bear Creek Basin. 
This includes the following drainages; Bear, Eagle, Shellrock, and 
Jelm Creeks. The debris flow can consist of rock, mud, vegetation 
and other loose materials.

Additional rainfall amounts of one half inch are possible in the 
warned area.

LAT...LON 4114 10598 4100 10591 4100 10626 4103 10628
      4112 10613

$$

Lyons

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:34 PM MDTSpecial Weather StatementCYSAlbany41 min
Jul 11, 10:23 PM MDTAreal Flood AdvisoryCYSCarbon3 hr
Jul 12, 1:32 PM MDTSpecial Weather StatementCYSPlatte43 min
Jul 12, 1:59 PM MDTSpecial Weather StatementCYSAlbany46 min
Jul 12, 5:34 PM MDTSpecial Weather StatementCYSConverse26 min

Nearby

Flash Flood Warnings in Wyoming, 2018Every flash flood warning in 2018

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.