Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 64, NWS Denver/Boulder, CO

June 15, 2012Arapahoe County, Douglas County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 15, 2012, 2:20 PM MDT for Arapahoe County, Douglas County, Colorado. It was in force for 40 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: Jun 15, 2012, 2:20 PM MDT (20:20 UTC)
Expired: Jun 15, 2012, 3:00 PM MDT
In force: 40 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Arapahoe County, CO, Douglas County, CO

The radar

The Denver radar (KFTG), 48 km from the middle of the area, began a volume at 20:20 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

Time	Report	Where	Remark
Jun 15, 2:23 PM MDT	HAIL 1.25	Highlands Ranch, CO

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.

Issued	Product	Office	Lasted
Jun 15, 1:35 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.3 hours before the alert went out and 156 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: 7 J/kg
Mixed-layer CIN: -278 J/kg
Mixed-layer LCL: 1830 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -227 m²/s²
0-3 km storm-relative helicity: 9 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.

985 
WUUS55 KBOU 152020
SVRBOU
COC005-035-152100-
/O.NEW.KBOU.SV.W.0064.120615T2020Z-120615T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
220 PM MDT FRI JUN 15 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL DOUGLAS COUNTY IN NORTHEAST COLORADO
  SOUTHWESTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO

* UNTIL 300 PM MDT

* AT 221 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL...
  AND DAMAGING WINDS UP TO ABOUT 60 MPH.  THIS STORM WAS LOCATED NEAR
  HIGHLANDS RANCH...OR 13 MILES SOUTH OF DENVER...MOVING EAST AT 20
  MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SURREY
  RIDGE...LOUVIERS...HIGHLANDS RANCH...GREENWOOD VILLAGE...BEVERLY
  HILLS...WESTERN CENTENNIAL...LITTLETON AND SOUTHEASTERN ENGLEWOOD.

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 3947 10509 3956 10507 3956 10505 3957 10505
      3962 10505 3963 10481 3946 10484
TIME...MOT...LOC 2021Z 281DEG 16KT 3954 10493
WIND...HAIL 60MPH 1.00IN

$$

2 follow-up statements

844 
WWUS55 KBOU 152029
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
229 PM MDT FRI JUN 15 2012

COC005-035-152100-
/O.CON.KBOU.SV.W.0064.000000T0000Z-120615T2100Z/
DOUGLAS CO-ARAPAHOE CO-
229 PM MDT FRI JUN 15 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM MDT
FOR SOUTHWESTERN ARAPAHOE AND NORTH CENTRAL DOUGLAS COUNTIES...

AT 229 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL...AND
DAMAGING WINDS UP TO ABOUT 60 MPH.  THIS STORM WAS LOCATED 2 MILES
WEST OF LONE TREE...OR 13 MILES SOUTH OF DENVER...MOVING EAST AT 20
MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
SURREY RIDGE...LOUVIERS...HIGHLANDS RANCH...GREENWOOD VILLAGE...
BEVERLY HILLS...WESTERN CENTENNIAL...LITTLETON...SOUTHEASTERN
ENGLEWOOD...SOUTHERN DENVER AND SOUTHWESTERN AURORA.

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 3947 10509 3956 10507 3956 10505 3957 10505
      3962 10505 3963 10481 3946 10484
TIME...MOT...LOC 2029Z 281DEG 16KT 3954 10490
WIND...HAIL 60MPH 1.00IN

$$

714 
WWUS55 KBOU 152055
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
255 PM MDT FRI JUN 15 2012

COC005-035-152105-
/O.EXP.KBOU.SV.W.0064.000000T0000Z-120615T2100Z/
DOUGLAS CO-ARAPAHOE CO-
255 PM MDT FRI JUN 15 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ARAPAHOE AND
NORTH CENTRAL DOUGLAS COUNTIES 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 3947 10509 3956 10507 3956 10505 3957 10505
      3962 10505 3963 10481 3946 10484
TIME...MOT...LOC 2055Z 281DEG 16KT 3952 10475

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 14, 8:40 PM MDT	Special Weather Statement	BOU	Lincoln	35 min
Jun 14, 9:08 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	37 min
Jun 14, 9:41 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	34 min
Jun 14, 10:11 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	49 min
Jun 15, 2:50 AM MDT	Special Weather Statement	BOU	Arapahoe	40 min
Jun 15, 1:49 PM MDT	Special Weather Statement	BOU	Jefferson	26 min
Jun 15, 2:14 PM MDT	Special Weather Statement	BOU	Douglas	31 min
Jun 15, 2:33 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver	42 min
Jun 15, 3:02 PM MDT	Tornado Warning	BOU	Adams	28 min
Jun 15, 3:27 PM MDT	Special Weather Statement	BOU	Adams, Arapahoe	33 min
Jun 15, 3:52 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe	38 min
Jun 15, 4:31 PM MDT	Special Weather Statement	BOU	Arapahoe	29 min
Jun 15, 5:21 PM MDT	Special Weather Statement	BOU	Lincoln	24 min
Jun 15, 5:41 PM MDT	Special Weather Statement	BOU	Washington	34 min
Jun 15, 5:59 PM MDT	Severe Thunderstorm Warning	BOU	Washington	31 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2012 Every severe thunderstorm warning in 2012

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.