Alert archive / Colorado / Mesoscale Discussions in 2017

Mesoscale Discussion 989

June 11, 20178 counties in Colorado; Albany County, Laramie County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2017, 2:49 PM MDT for 8 counties in Colorado; Albany County, Laramie County, Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 11, 2017, 2:49 PM MDT (20:49 UTC)
Expired
Jun 11, 2017, 5:15 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Adams County, CO, Arapahoe County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Jefferson County, CO, Larimer County, CO, Weld County, CO, Albany County, WY, Laramie County, WY

The radar

The Denver radar (KFTG), 74 km from the middle of the area, began a volume at 20:50 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

Grand Junction, CO (KGJT), launched 12:00Z, 8.8 hours before the alert went out and 327 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, Grand Junction, CO at 12:00Z on 2017-06-11Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2017-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3447 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 10, 9:01 PM MDTSevere Thunderstorm WatchSPCWeston7 hr
Jun 10, 10:56 PM MDTMesoscale DiscussionSPCWeston2 hr

Nearby

Mesoscale Discussions in Colorado, 2017Mesoscale Discussions in Wyoming, 2017Every mesoscale discussion 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.