Alert archive / Wyoming / Flash Flood Warnings in 2013

Flash Flood Warning 13, NWS Cheyenne, WY

September 12, 2013Albany County, Laramie County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Sep 12, 2013, 9:58 PM MDT for Albany County, Laramie County, Wyoming. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 12, 2013, 9:58 PM MDT (03:58 UTC)
Expired
Sep 13, 2013, 4:00 AM MDT
In force
6 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

Counties Albany County, WY, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 62 km from the middle of the area, began a volume at 04:02 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.

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 4.0 hours before the alert went out and 240 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 00:00Z on 2013-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 175 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 00:00Z on 2013-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -116 square meters per square second.193958Sfc1 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
175 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
680 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-116 m²/s²
0-3 km storm-relative helicity
-58 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-1.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

023 
WGUS55 KCYS 130358
FFWCYS
WYC001-021-131000-
/O.NEW.KCYS.FF.W.0013.130913T0358Z-130913T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
958 PM MDT THU SEP 12 2013

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN ALBANY COUNTY IN SOUTHEAST WYOMING...
  SOUTHWESTERN LARAMIE COUNTY IN SOUTHEAST WYOMING...

* UNTIL 400 AM MDT FRIDAY

* AT 957 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
  AREA OF VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR          
  ESTIMATED RAIN FALL OF 2 TO 3 INCHES HAS FALLEN OVER THE WARNED    
  AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BUFORD...CRYSTAL LAKE CAMPGROUND...CRYSTAL LAKE RESERVOIR...GRANITE
  SPRINGS CAMPGROUND...GRANITE SPRINGS RESERVOIR...HUTTON LAKE...
  PUMPKIN VINE...TIE SIDING...VEDAUWOO AND VEDAUWOO CAMPGROUND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF ONE TO ONE AND A HALF INCHES ARE 
POSSIBLE IN THE WARNED AREA.

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 4120 10573 4121 10521 4100 10518 4099 10587

$$

CLAYCOMB
1 follow-up statement
287 
WGUS75 KCYS 130720
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
120 AM MDT FRI SEP 13 2013

WYC001-021-130733-
/O.CAN.KCYS.FF.W.0013.000000T0000Z-130913T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALBANY WY-LARAMIE WY-
120 AM MDT FRI SEP 13 2013

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHWESTERN
LARAMIE AND SOUTHEASTERN ALBANY COUNTIES IS CANCELLED...

THE ALBANY COUNTY SHERIFFS OFFICE HAD NO REPORTS OF FLOODING FROM 
THE FLASH FLOOD WARNING AREA. 

DOPPLER RADAR REFLECTIVITY INDICATES THAT ONLY SCATTERED AREAS OF 
LIGHT RAIN WILL CONTINUE FOR THE NEXT SEVERAL HOURS...THUS THE 
THREAT OF FLASH FLOODING HAS DIMINISHED.

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 4120 10573 4121 10521 4100 10518 4099 10587

$$

RUBIN

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 2:43 PM MDTAreal Flood AdvisoryCYSPlatte4 hr
Sep 13, 5:22 PM MDTAreal Flood AdvisoryCYSAlbany, Laramie6 hr

Nearby

Flash Flood Warnings in Wyoming, 2013Every flash flood warning in 2013

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.