Alert archive / Colorado / Tornado Warnings in 2011

Tornado Warning 11, NWS Denver/Boulder, CO

May 30, 2011Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 30, 2011, 2:24 PM MDT for Weld County, Colorado. It was in force for 36 min. 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
May 30, 2011, 2:24 PM MDT (20:24 UTC)
Expired
May 30, 2011, 3:00 PM MDT
In force
36 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

County Weld County, CO

The radar

The Denver radar (KFTG), 47 km from the middle of the area, began a volume at 20:27 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 30, 2:26 PM MDTHAIL 1.25Keenesburg, CO

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

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.4 hours before the alert went out and 105 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 2011-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 19 joules per kilogram.LCLLFCEL10008507005003002001001 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, Denver, CO at 12:00Z on 2011-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 square meters per square second.1939587897Sfc1 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
19 J/kg
Mixed-layer CIN
-134 J/kg
Mixed-layer LCL
1603 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

192 
WFUS55 KBOU 302024
TORBOU
COC123-302100-
/O.NEW.KBOU.TO.W.0011.110530T2024Z-110530T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
224 PM MDT MON MAY 30 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 300 PM MDT

* AT 224 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 2 MILES
  NORTHWEST OF PROSPECT VALLEY...OR 27 MILES SOUTHEAST OF GREELEY.
  THIS STORM WAS MOVING NORTHEAST AT 15 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ROGGEN...
  PROSPECT VALLEY AND KEENESBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4031 10448 4031 10416 4001 10418 4001 10467
TIME...MOT...LOC 2024Z 211DEG 25KT 4010 10443

$$
3 follow-up statements
388 
WWUS55 KBOU 302030
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
230 PM MDT MON MAY 30 2011

COC123-302100-
/O.CON.KBOU.TO.W.0011.000000T0000Z-110530T2100Z/
WELD CO-
230 PM MDT MON MAY 30 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM MDT FOR SOUTH
CENTRAL WELD COUNTY...

AT 231 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM WAS
LOCATED 3 MILES EAST OF PROSPECT VALLEY...OR 30 MILES SOUTHEAST OF
GREELEY. THIS STORM WAS MOVING NORTHEAST AT 15 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
ROGGEN...PROSPECT VALLEY AND KEENESBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4031 10448 4031 10416 4001 10418 4001 10455
TIME...MOT...LOC 2031Z 211DEG 25KT 4009 10436

$$
592 
WWUS55 KBOU 302041
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
241 PM MDT MON MAY 30 2011

COC123-302100-
/O.CON.KBOU.TO.W.0011.000000T0000Z-110530T2100Z/
WELD CO-
241 PM MDT MON MAY 30 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM MDT FOR SOUTH
CENTRAL WELD COUNTY...

AT 241 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM WAS
LOCATED NEAR ROGGEN...OR 24 MILES SOUTHEAST OF GREELEY. THIS STORM
WAS MOVING NORTHEAST AT 15 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
ROGGEN...PROSPECT VALLEY AND KEENESBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4031 10448 4031 10416 4001 10418 4001 10455
TIME...MOT...LOC 2041Z 211DEG 25KT 4020 10438

$$
902 
WWUS55 KBOU 302056
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
256 PM MDT MON MAY 30 2011

COC123-302107-
/O.EXP.KBOU.TO.W.0011.000000T0000Z-110530T2100Z/
WELD CO-
256 PM MDT MON MAY 30 2011

...THE TORNADO WARNING FOR SOUTH CENTRAL WELD COUNTY WILL EXPIRE AT
300 PM MDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND IS NO
LONGER EXPECTED TO PRODUCE SEVERE WEATHER.

LAT...LON 4031 10448 4031 10416 4001 10418 4001 10455
TIME...MOT...LOC 2057Z 211DEG 25KT 4030 10431

$$

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 9:42 PM MDTAreal Flood AdvisoryBOUGrand4 days
May 30, 1:12 PM MDTSevere Thunderstorm WarningBOUWeld20 min
May 30, 2:02 PM MDTSevere Thunderstorm WarningBOUWeld28 min
May 30, 2:20 PM MDTTornado WarningBOUWeld25 min
May 30, 2:32 PM MDTSevere Thunderstorm WarningBOUAdams28 min
May 30, 2:49 PM MDTTornado WarningBOUAdams26 min
May 30, 3:00 PM MDTTornado WarningBOUAdams, Morgan, Weld30 min
May 30, 3:34 PM MDTSpecial Weather StatementBOUMorgan41 min
May 30, 3:35 PM MDTSpecial Weather StatementBOULogan40 min
May 30, 3:53 PM MDTTornado WarningBOUWashington22 min
May 30, 3:59 PM MDTSpecial Weather StatementBOULogan46 min
May 30, 4:32 PM MDTSpecial Weather StatementBOUPhillips, Sedgwick28 min
May 30, 5:00 PM MDTSpecial Weather StatementBOUPhillips, Sedgwick30 min
May 30, 5:04 PM MDTSevere Thunderstorm WarningBOUSedgwick22 min

Nearby

Tornado Warnings in Colorado, 2011Every tornado warning in 2011Tornadoes in 2011

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.