Alert archive / Colorado / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 252, NWS Denver/Boulder, CO

August 30, 2019Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 30, 2019, 7:43 PM MDT for Weld County, Colorado. It was in force for 47 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 30, 2019, 7:43 PM MDT (01:43 UTC)
Expired
Aug 30, 2019, 8:30 PM MDT
In force
47 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 69 km from the middle of the area, began a volume at 01:45 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 00:00Z, 1.7 hours before the alert went out and 134 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 2019-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 335 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 2019-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
335 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
2693 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

899 
WUUS55 KBOU 310143
SVRBOU
COC123-310230-
/O.NEW.KBOU.SV.W.0252.190831T0143Z-190831T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
743 PM MDT Fri Aug 30 2019

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  North central Weld County in northeastern Colorado...

* Until 830 PM MDT.

* At 743 PM MDT, a severe thunderstorm was located near Hereford, or
  31 miles southeast of Cheyenne, moving east at 15 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
           vehicles is expected.

* Locations impacted include...
  Hereford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4080 10388 4090 10431 4100 10432 4100 10389
TIME...MOT...LOC 0143Z 280DEG 15KT 4094 10425 

HAIL...1.25IN
WIND...60MPH
 
$$

GIMMESTAD
1 follow-up statement
012 
WWUS55 KBOU 310214
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
814 PM MDT Fri Aug 30 2019

COC123-310230-
/O.CON.KBOU.SV.W.0252.000000T0000Z-190831T0230Z/
Weld CO-
814 PM MDT Fri Aug 30 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM MDT
FOR NORTH CENTRAL WELD COUNTY...

At 813 PM MDT, a severe thunderstorm was located 6 miles east of 
Grover, or 32 miles southwest of Kimball, moving east at 15 mph. 
Another severe storm was just east of Pawnee Buttes moving northeast 
at 25 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
         vehicles is expected.

These severe thunderstorms will remain over mainly rural areas of 
north central Weld County from east of Grover to northeast of Pawnee 
Buttes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4080 10388 4088 10422 4091 10421 4100 10413
      4100 10389
TIME...MOT...LOC 0213Z 286DEG 15KT 4089 10410 

HAIL...1.25IN
WIND...60MPH
 
$$

GIMMESTAD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 7:18 PM MDTSpecial Weather StatementBOUWeld42 min
Aug 30, 8:07 PM MDTSpecial Weather StatementBOUMorgan38 min
Aug 30, 8:47 PM MDTSpecial Weather StatementBOUMorgan43 min
Aug 30, 8:57 PM MDTAreal Flood AdvisoryBOUWeld2 hr
Aug 30, 9:22 PM MDTSpecial Weather StatementBOUWeld53 min
Aug 30, 10:38 PM MDTSpecial Weather StatementBOUMorgan52 min
Aug 30, 11:31 PM MDTSevere Thunderstorm WarningBOUWashington44 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2019Every severe thunderstorm warning in 2019

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.