Alert archive / Colorado / Tornado Warnings in 2018

Tornado Warning 32, NWS Denver/Boulder, CO

July 26, 2018Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jul 26, 2018, 6:43 PM MDT for Weld County, Colorado. It was in force for 17 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
Jul 26, 2018, 6:43 PM MDT (00:43 UTC)
Expired
Jul 26, 2018, 7:00 PM MDT
In force
17 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 33 km from the middle of the area, began a volume at 00:44 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
Jul 26, 1:49 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 0.7 hours before the alert went out and 164 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 00:00Z on 2018-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 130 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2018-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.19395878Sfc1 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
130 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
2250 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted.

335 
WFUS55 KBOU 270043
TORBOU
COC123-270100-
/O.NEW.KBOU.TO.W.0032.180727T0043Z-180727T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
643 PM MDT THU JUL 26 2018

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  North central Weld County in northeastern Colorado...

* Until 700 PM MDT.
    
* At 643 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 5 miles east of Rockport, or 15 miles south of
  Cheyenne, moving southeast at 40 mph.

  HAZARD...Tornado.

  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.

* This tornadic thunderstorm will remain over mainly rural areas of
  north central Weld County.

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 outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4080 10473 4099 10485 4099 10448 4085 10439
TIME...MOT...LOC 0043Z 325DEG 36KT 4093 10469 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

RJK
1 follow-up statement
157 
WWUS55 KBOU 270057
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
657 PM MDT THU JUL 26 2018

COC123-270106-
/O.EXP.KBOU.TO.W.0032.000000T0000Z-180727T0100Z/
Weld CO-
657 PM MDT THU JUL 26 2018

...THE TORNADO WARNING FOR NORTH CENTRAL WELD COUNTY WILL EXPIRE AT
700 PM MDT...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
northeastern Colorado.

LAT...LON 4080 10473 4099 10485 4099 10448 4085 10439
TIME...MOT...LOC 0056Z 323DEG 35KT 4085 10460 

$$

RJK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 26, 6:28 PM MDTSevere Thunderstorm WarningBOUWeld47 min
Jul 26, 6:50 PM MDTSevere Thunderstorm WarningBOULarimer40 min
Jul 26, 7:12 PM MDTSevere Thunderstorm WarningBOUWeld32 min
Jul 26, 8:00 PM MDTSevere Thunderstorm WarningBOULarimer, Weld30 min
Jul 26, 8:24 PM MDTSevere Thunderstorm WarningBOUWeld36 min
Jul 26, 9:10 PM MDTSevere Thunderstorm WarningBOUAdams, Denver35 min
Jul 26, 9:45 PM MDTSevere Thunderstorm WarningBOUArapahoe30 min
Jul 26, 10:38 PM MDTSevere Thunderstorm WarningBOUElbert52 min
Jul 27, 1:53 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick52 min
Jul 27, 3:08 PM MDTSevere Thunderstorm WarningBOUElbert37 min
Jul 27, 3:26 PM MDTTornado WarningBOUMorgan, Weld34 min
Jul 27, 3:43 PM MDTTornado WarningBOUWashington32 min
Jul 27, 3:45 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Weld25 min
Jul 27, 3:47 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert43 min
Jul 27, 4:08 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert, Lincoln, Washington41 min
Jul 27, 4:10 PM MDTTornado WarningBOUAdams, Arapahoe35 min
Jul 27, 4:28 PM MDTTornado Warning Tornado observedBOUArapahoe32 min
Jul 27, 4:35 PM MDTTornado WarningBOUWashington25 min
Jul 27, 4:57 PM MDTSevere Thunderstorm WarningBOUDouglas, Jefferson33 min
Jul 27, 4:57 PM MDTTornado WarningBOULincoln19 min
Jul 27, 5:09 PM MDTAreal Flood AdvisoryBOUWashington2 hr
Jul 27, 5:29 PM MDTAreal Flood AdvisoryBOULincoln2 hr
Jul 27, 5:56 PM MDTSevere Thunderstorm WarningBOULarimer, Weld34 min

Nearby

Tornado Warnings in Colorado, 2018Every tornado warning in 2018Tornadoes in 2018

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.