Alert archive / Colorado / Special Weather Statements in 2021

Special Weather Statement, NWS Denver/Boulder, CO

August 6, 2021Logan County, Colorado

NWS Denver/Boulder, CO issued this special weather statement at Aug 6, 2021, 6:15 PM MDT for Logan County, Colorado. It was in force for 45 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 6, 2021, 6:15 PM MDT (00:15 UTC)
Expired
Aug 6, 2021, 7:00 PM MDT
In force
45 min
Issued by
NWS Denver/Boulder, CO
Hail
0.25 in
Wind
50

County Logan County, CO

The radar

The Cheyenne radar (KCYS), 166 km from the middle of the area, began a volume at 00:18 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, 0.3 hours before the alert went out and 97 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 2021-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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 2021-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -32 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
4 J/kg
Mixed-layer CIN
-256 J/kg
Mixed-layer LCL
3329 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-32 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

255 
WWUS85 KBOU 070015
SPSBOU

Special Weather Statement
National Weather Service Denver CO
615 PM MDT Fri Aug 6 2021
 
COZ048-070100-
Logan County CO-
615 PM MDT Fri Aug 6 2021

...Strong thunderstorms will impact portions of Logan County through
700 PM MDT...

At 614 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 3 miles north of North Sterling Reservoir to 7
miles north of Burdett, or along a line extending from 26 miles
southwest of Sidney to 14 miles southeast of Sterling. Movement was
east at 25 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Sterling, Fleming, Iliff, Peetz, Crook, St Petersburg, Proctor,
Padroni, Twin Buttes and North Sterling Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 4070 10266 4049 10266 4044 10293 4044 10307
      4088 10339 4100 10327 4100 10272
TIME...MOT...LOC 0014Z 260DEG 22KT 4084 10329 4048 10300 

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

$$

SCHLATTER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 6:24 PM MDTSpecial Weather StatementBOUJackson36 min
Aug 6, 6:53 PM MDTFlash Flood WarningBOULarimer2 hr
Aug 6, 7:36 PM MDTSpecial Weather StatementBOULarimer24 min
Aug 6, 7:58 PM MDTAreal Flood AdvisoryBOULarimer2 hr
Aug 6, 10:06 PM MDTAreal Flood AdvisoryBOULarimer84 min
Aug 7, 1:08 PM MDTSpecial Weather StatementBOULincoln52 min
Aug 7, 1:48 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln42 min
Aug 7, 2:29 PM MDTSevere Thunderstorm WarningBOULincoln33 min

Nearby

Special Weather Statements in Colorado, 2021Every special weather statement in 2021

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.