Alert archive / Colorado / Tornado Watches in 2015

Tornado Watch 258

June 5, 201524 counties in Colorado

The Storm Prediction Center issued this tornado watch at Jun 5, 2015, 1:09 PM MDT for 24 counties in Colorado. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 5, 2015, 1:09 PM MDT (19:09 UTC)
Expired
Jun 5, 2015, 7:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 24 counties

Adams County, CO, Arapahoe County, CO, Baca County, CO, Bent County, CO, Boulder County, CO, Broomfield County, CO, Crowley County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Huerfano County, CO, Jefferson County, CO, Kiowa County, CO, Larimer County, CO, Las Animas County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Otero County, CO, Prowers County, CO, Pueblo County, CO, Washington County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 51 km from the middle of the area, began a volume at 19:12 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
80%
One or more hailstones of 2 inches or more
60%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 5, 1:48 PM MDTTornado WarningBOUAdams, Arapahoe42 min
Jun 5, 2:17 PM MDTTornado WarningBOUArapahoe, Douglas, Elbert43 min
Jun 5, 2:20 PM MDTSevere Thunderstorm WarningPUBLas Animas55 min
Jun 5, 2:33 PM MDTSevere Thunderstorm WarningPUBLas Animas, Otero, Pueblo30 min
Jun 5, 3:04 PM MDTTornado WarningBOUAdams, Arapahoe26 min
Jun 5, 3:27 PM MDTTornado WarningBOUAdams, Arapahoe33 min
Jun 5, 3:41 PM MDTSevere Thunderstorm WarningBOULincoln, Washington49 min
Jun 5, 3:51 PM MDTSevere Thunderstorm WarningPUBBent, Las Animas, Otero24 min
Jun 5, 4:03 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan42 min
Jun 5, 4:31 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe29 min
Jun 5, 4:34 PM MDTSevere Thunderstorm WarningBOULincoln, Washington26 min
Jun 5, 4:36 PM MDTSevere Thunderstorm WarningPUBBaca, Las Animas33 min
Jun 5, 4:44 PM MDTTornado WarningBOUWashington31 min
Jun 5, 4:58 PM MDTTornado WarningBOUAdams, Washington32 min
Jun 5, 5:24 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington39 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 7.2 hours before the alert went out and 109 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 2015-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 356 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2015-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 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
356 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
888 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
68 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.

350 
WWUS20 KWNS 051906
SEL8  
SPC WW 051906
COZ000-060100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 258
NWS STORM PREDICTION CENTER NORMAN OK
110 PM MDT FRI JUN 5 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  EASTERN COLORADO

* EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 110 PM UNTIL
  700 PM MDT.

* PRIMARY THREATS INCLUDE...
  A COUPLE TORNADOES POSSIBLE
  WIDESPREAD LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2.5
    INCHES IN DIAMETER LIKELY
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

SUMMARY...THUNDERSTORMS ARE EXPECTED TO CONTINUE TO INTENSIFY OVER
THE MOUNTAINS AND FOOTHILLS OF COLORADO THIS AFTERNOON AND SPREAD
ACROSS THE WATCH AREA.  SUFFICIENT CAPE AND SHEAR PARAMETERS SUGGEST
A RISK OF VERY LARGE HAIL AND ISOLATED TORNADOES IN THE STRONGEST
STORMS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 45 MILES NORTHEAST OF FORT
COLLINS COLORADO TO 40 MILES EAST SOUTHEAST OF TRINIDAD COLORADO.
 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

&&

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24030.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 4, 6:06 PM MDTTornado WatchSPCKit Carson, Yuma5 hr
Jun 4, 7:20 PM MDTMesoscale DiscussionSPCBent, Crowley, El Paso, Otero, Prowers, Pueblo2 hr
Jun 4, 8:20 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Broomfield, Denver, Douglas, Elbert and 2 more115 min
Jun 5, 12:49 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Bent, Broomfield, Crowley, Denver and 14 more86 min
Jun 5, 4:22 PM MDTMesoscale DiscussionSPCCheyenne, Kit Carson, Phillips, Yuma53 min
Jun 5, 4:44 PM MDTTornado WatchSPCCheyenne, Kit Carson, Phillips, Sedgwick, Yuma7 hr
Jun 5, 5:59 PM MDTMesoscale DiscussionSPCKit Carson61 min

Nearby

Tornado Watches in Colorado, 2015Every tornado watch in 2015

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.