Alert archive / Colorado / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 49, NWS Denver/Boulder, CO

June 27, 2017Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 27, 2017, 2:17 PM MDT for Washington County, Colorado. It was in force for 28 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
Jun 27, 2017, 2:17 PM MDT (20:17 UTC)
Expired
Jun 27, 2017, 2:45 PM MDT
In force
28 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Washington County, CO

The radar

The Goodland radar (KGLD), 115 km from the middle of the area, began a volume at 20:19 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 (KDEN), launched 12:00Z, 8.3 hours before the alert went out and 31 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 2017-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 2017-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
34 J/kg
Mixed-layer CIN
-526 J/kg
Mixed-layer LCL
2742 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

503 
WUUS55 KBOU 272017
SVRBOU
COC121-272045-
/O.NEW.KBOU.SV.W.0049.170627T2017Z-170627T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
217 PM MDT TUE JUN 27 2017

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Southeastern Washington County in northeastern Colorado...

* Until 245 PM MDT

* At 216 PM MDT, a severe thunderstorm was located near Arickaree
  School, or 28 miles north of Flagler, moving east at 30 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Arickaree School and Cope. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3957 10310 3980 10310 3981 10280 3957 10281
TIME...MOT...LOC 2016Z 268DEG 25KT 3970 10302 

HAIL...1.00IN
WIND...60MPH
 
$$

RPK
2 follow-up statements
137 
WWUS55 KBOU 272031
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
231 PM MDT TUE JUN 27 2017

COC121-272045-
/O.CON.KBOU.SV.W.0049.000000T0000Z-170627T2045Z/
Washington CO-
231 PM MDT TUE JUN 27 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM MDT
FOR SOUTHEASTERN WASHINGTON COUNTY...

At 230 PM MDT, a severe thunderstorm was located near Cope, or 28
miles north of Seibert, moving east at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Cope.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3957 10302 3980 10300 3981 10280 3957 10281
TIME...MOT...LOC 2030Z 268DEG 25KT 3970 10289 

HAIL...1.00IN
WIND...60MPH
 
$$

RPK
528 
WWUS55 KBOU 272045
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
245 PM MDT TUE JUN 27 2017

COC121-272055-
/O.EXP.KBOU.SV.W.0049.000000T0000Z-170627T2045Z/
Washington CO-
245 PM MDT TUE JUN 27 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WASHINGTON COUNTY
HAS EXPIRED...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning has been allowed to expire.

LAT...LON 3957 10302 3980 10300 3981 10280 3957 10281
TIME...MOT...LOC 2045Z 268DEG 25KT 3970 10276 

$$

RPK

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 7:10 PM MDTSevere Thunderstorm WarningBOULincoln35 min
Jun 26, 7:59 PM MDTAreal Flood AdvisoryBOULincoln3 hr
Jun 27, 2:07 PM MDTSpecial Weather StatementBOUWashington38 min
Jun 27, 5:28 PM MDTSevere Thunderstorm WarningBOUSedgwick32 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2017Every severe thunderstorm warning in 2017

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.