Alert archive / Wyoming / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 21, NWS Cheyenne, WY

May 20, 2014Converse County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 20, 2014, 2:53 PM MDT for Converse County, Wyoming. It was in force for 52 min. 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
May 20, 2014, 2:53 PM MDT (20:53 UTC)
Expired
May 20, 2014, 3:45 PM MDT
In force
52 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Converse County, WY

The radar

The Cheyenne radar (KCYS), 189 km from the middle of the area, began a volume at 20:54 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
May 20, 3:14 PM MDTHAIL 17 Sw Douglas, WYALL HAIL, NO RAIN.
May 20, 3:20 PM MDTHAIL 0.53 Sw Douglas, WYHAIL COVERS THE GROUND

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 20, 2:31 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 8.9 hours before the alert went out and 242 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, Riverton, WY at 12:00Z on 2014-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2014-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1701 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
102 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.

887 
WUUS55 KCYS 202053
SVRCYS
WYC009-202145-
/O.NEW.KCYS.SV.W.0021.140520T2053Z-140520T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
253 PM MDT TUE MAY 20 2014

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL CONVERSE COUNTY IN EAST CENTRAL WYOMING...

* UNTIL 345 PM MDT

* AT 249 PM MDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR LAPRELE
  RESERVOIR...AND MOVING EAST AT 15 MPH.

  HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL.

  SOURCE...RADAR INDICATED.

  IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE TO
           ROOFS...SIDING AND TREES.

* LOCATIONS IMPACTED INCLUDE...
  DOUGLAS.

THIS INCLUDES INTERSTATE 25 IN WYOMING BETWEEN MILEPOSTS 129 AND 150.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN
CHEYENNE.

TORRENTIAL RAINFALL IS OCCURRING WITH THIS STORM...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS!

&&

LAT...LON 4293 10539 4268 10518 4264 10560 4274 10569
TIME...MOT...LOC 2053Z 251DEG 14KT 4273 10554

HAIL...1.00IN
WIND...60MPH

$$

CLAYCOMB
3 follow-up statements
530 
WWUS55 KCYS 202112
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
312 PM MDT TUE MAY 20 2014

WYC009-202145-
/O.CON.KCYS.SV.W.0021.000000T0000Z-140520T2145Z/
CONVERSE WY-
312 PM MDT TUE MAY 20 2014

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CENTRAL
CONVERSE COUNTY UNTIL 345 PM MDT...

AT 311 PM MDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR DOUGLAS...AND
MOVING EAST AT 15 MPH.

HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE TO
         ROOFS...SIDING AND TREES.

LOCATIONS IMPACTED INCLUDE...
DOUGLAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN
CHEYENNE.

TORRENTIAL RAINFALL IS OCCURRING WITH THIS STORM...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS!

&&

LAT...LON 4291 10538 4268 10518 4266 10550 4276 10558
TIME...MOT...LOC 2113Z 251DEG 14KT 4275 10544

HAIL...1.00IN
WIND...60MPH

$$

CLAYCOMB
044 
WWUS55 KCYS 202124
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
324 PM MDT TUE MAY 20 2014

WYC009-202145-
/O.CON.KCYS.SV.W.0021.000000T0000Z-140520T2145Z/
CONVERSE WY-
324 PM MDT TUE MAY 20 2014

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CENTRAL
CONVERSE COUNTY UNTIL 345 PM MDT...

AT 322 PM MDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR DOUGLAS...AND
MOVING EAST AT 15 MPH.

HAZARD...QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...DAMAGE TO VEHICLES IS EXPECTED.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF CENTRAL CONVERSE COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN
CHEYENNE.

&&

LAT...LON 4291 10538 4271 10521 4269 10527 4280 10547
TIME...MOT...LOC 2124Z 254DEG 37KT 4278 10532

HAIL...1.00IN
WIND...<50MPH

$$

CLAYCOMB
625 
WWUS55 KCYS 202132
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
332 PM MDT TUE MAY 20 2014

WYC009-202142-
/O.CAN.KCYS.SV.W.0021.000000T0000Z-140520T2145Z/
CONVERSE WY-
332 PM MDT TUE MAY 20 2014

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL CONVERSE COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 9 PM THIS EVENING.

LAT...LON 4291 10538 4271 10521 4269 10527 4280 10547
TIME...MOT...LOC 2132Z 254DEG 37KT 4280 10521

$$

CLAYCOMB

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 6:12 PM MDTSevere Thunderstorm WarningCYSLaramie63 min
May 19, 6:54 PM MDTSpecial Weather StatementCYSLaramie51 min
May 20, 1:31 PM MDTSpecial Weather StatementCYSConverse59 min
May 20, 1:41 PM MDTSpecial Weather StatementCYSPlatte64 min
May 20, 1:50 PM MDTSevere Thunderstorm WarningCYSPlatte40 min
May 20, 2:30 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte45 min
May 20, 2:33 PM MDTSpecial Weather StatementCYSConverse57 min
May 20, 2:54 PM MDTSpecial Weather StatementCYSPlatte66 min
May 20, 3:17 PM MDTSpecial Weather StatementCYSGoshen58 min
May 20, 3:52 PM MDTSevere Thunderstorm WarningCYSGoshen38 min
May 20, 4:33 PM MDTSpecial Weather StatementCYSGoshen57 min
May 20, 4:45 PM MDTSpecial Weather StatementCYSConverse60 min
May 20, 4:47 PM MDTSpecial Weather StatementCYSGoshen58 min
May 20, 5:00 PM MDTFlash Flood WarningCYSGoshen6 hr

Nearby

Severe Thunderstorm Warnings in Wyoming, 2014Every severe thunderstorm warning in 2014

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.