Alert archive / Colorado / Tornado Warnings in 2015

Tornado Warning 48, NWS Denver/Boulder, CO

August 7, 2015Adams County, Arapahoe County, Washington County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Aug 7, 2015, 5:50 PM MDT for Adams County, Arapahoe County, Washington County, Colorado. It was in force for 40 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
Aug 7, 2015, 5:50 PM MDT (23:50 UTC)
Expired
Aug 7, 2015, 6:30 PM MDT
In force
40 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

Counties Adams County, CO, Arapahoe County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 66 km from the middle of the area, began a volume at 23:53 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 7, 3:05 PM MDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 11.8 hours before the alert went out and 49 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 2015-08-07Temperature 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 km15 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 2015-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3310 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
43 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.

528 
WFUS55 KBOU 072350
TORBOU
COC001-005-121-080030-
/O.NEW.KBOU.TO.W.0048.150807T2350Z-150808T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
550 PM MDT FRI AUG 7 2015

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN ARAPAHOE COUNTY IN NORTHEASTERN COLORADO...
  SOUTHEASTERN ADAMS COUNTY IN NORTHEASTERN COLORADO...
  SOUTHWESTERN WASHINGTON COUNTY IN NORTHEASTERN COLORADO...

* UNTIL 630 PM MDT
    
* AT 549 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED 9 MILES NORTHWEST OF COTTONWOOD VALLEY...OR 34
  MILES NORTH OF LIMON...MOVING EAST AT 25 MPH.

  HAZARD...TORNADO AND PING PONG BALL SIZE HAIL. 

  SOURCE...RADAR INDICATED ROTATION. 

  IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
           SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. 
           DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE 
           DAMAGE IS LIKELY. 

* LOCATIONS IMPACTED INCLUDE...
  LAST CHANCE...COTTONWOOD VALLEY AND WOODLIN SCHOOL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3961 10391 3979 10405 3994 10356 3970 10345
TIME...MOT...LOC 2349Z 249DEG 20KT 3974 10392 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

RTG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 2:54 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld51 min
Aug 7, 3:42 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld33 min
Aug 7, 4:05 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert25 min
Aug 7, 4:17 PM MDTAreal Flood AdvisoryBOUMorgan118 min
Aug 7, 4:21 PM MDTTornado WarningBOUMorgan24 min
Aug 7, 4:28 PM MDTSevere Thunderstorm WarningBOUElbert32 min
Aug 7, 4:39 PM MDTSevere Thunderstorm WarningBOUMorgan51 min
Aug 7, 5:14 PM MDTTornado WarningBOUMorgan31 min
Aug 7, 5:32 PM MDTAreal Flood AdvisoryBOUMorgan118 min
Aug 7, 5:33 PM MDTSevere Thunderstorm WarningBOULogan, Morgan42 min
Aug 7, 5:44 PM MDTSevere Thunderstorm WarningBOUMorgan31 min
Aug 7, 5:55 PM MDTSevere Thunderstorm WarningBOUWashington50 min

Nearby

Tornado Warnings in Colorado, 2015Every tornado warning in 2015Tornadoes 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.