Alert archive / Colorado / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 13, NWS Denver/Boulder, CO

May 30, 2011Adams County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 30, 2011, 2:32 PM MDT for Adams County, Colorado. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 30, 2011, 2:32 PM MDT (20:32 UTC)
Expired: May 30, 2011, 3:00 PM MDT
In force: 28 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.25 in
Wind: 50.0 mph

County Adams County, CO

The radar

The Denver radar (KFTG), 17 km from the middle of the area, began a volume at 20:32 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 (KDNR), launched 12:00Z, 8.5 hours before the alert went out and 101 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

896 
WUUS55 KBOU 302032
SVRBOU
COC001-302100-
/O.NEW.KBOU.SV.W.0013.110530T2032Z-110530T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
232 PM MDT MON MAY 30 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL ADAMS COUNTY IN NORTHEAST COLORADO

* UNTIL 300 PM MDT

* AT 232 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL. 
  THIS STORM WAS LOCATED OVER CENTRAL ADAMS COUNTY...OR 25 MILES
  NORTHEAST OF DENVER...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF THE
  WARNED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

&&

LAT...LON 3999 10418 3990 10429 3980 10440 3976 10457
      3989 10458 3998 10467
TIME...MOT...LOC 2032Z 237DEG 26KT 3991 10450
WIND...HAIL <50MPH 1.25IN

$$

1 follow-up statement

301 
WWUS55 KBOU 302059
SVSBOU

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

COC001-302109-
/O.EXP.KBOU.SV.W.0013.000000T0000Z-110530T2100Z/
ADAMS CO-
259 PM MDT MON MAY 30 2011

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL ADAMS 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 3999 10418 3990 10429 3980 10440 3976 10457
      3989 10458 3998 10467
TIME...MOT...LOC 2059Z 237DEG 26KT 4002 10429

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 29, 9:42 PM MDT	Areal Flood Advisory	BOU	Grand	4 days
May 30, 1:12 PM MDT	Severe Thunderstorm Warning	BOU	Weld	20 min
May 30, 2:02 PM MDT	Severe Thunderstorm Warning	BOU	Weld	28 min
May 30, 2:20 PM MDT	Tornado Warning	BOU	Weld	25 min
May 30, 2:24 PM MDT	Tornado Warning	BOU	Weld	36 min
May 30, 2:49 PM MDT	Tornado Warning	BOU	Adams	26 min
May 30, 3:00 PM MDT	Tornado Warning	BOU	Adams, Morgan, Weld	30 min
May 30, 3:34 PM MDT	Special Weather Statement	BOU	Morgan	41 min
May 30, 3:35 PM MDT	Special Weather Statement	BOU	Logan	40 min
May 30, 3:53 PM MDT	Tornado Warning	BOU	Washington	22 min
May 30, 3:59 PM MDT	Special Weather Statement	BOU	Logan	46 min
May 30, 4:32 PM MDT	Special Weather Statement	BOU	Phillips, Sedgwick	28 min
May 30, 5:00 PM MDT	Special Weather Statement	BOU	Phillips, Sedgwick	30 min
May 30, 5:04 PM MDT	Severe Thunderstorm Warning	BOU	Sedgwick	22 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2011 Every severe thunderstorm warning 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.