Alert archive / Colorado / Mesoscale Discussions in 2018

Mesoscale Discussion 452

May 18, 201810 counties in Colorado

The Storm Prediction Center issued this mesoscale discussion at May 18, 2018, 3:06 PM MDT for 10 counties in Colorado. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: May 18, 2018, 3:06 PM MDT (21:06 UTC)
Expired: May 18, 2018, 5:00 PM MDT
In force: 114 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Jefferson County, CO, Larimer County, CO, Morgan County, CO, Washington County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 59 km from the middle of the area, began a volume at 21:09 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, 9.1 hours before the alert went out and 114 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 190 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 862 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.4

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.

Issued	Product	Office	Counties	Lasted
May 17, 6:47 PM MDT	Mesoscale Discussion	SPC	Logan, Phillips, Sedgwick	58 min
May 17, 9:03 PM MDT	Mesoscale Discussion	SPC	Sedgwick	117 min
May 18, 1:43 PM MDT	Mesoscale Discussion	SPC	Baca, Bent, Kiowa, Prowers	2 hr
May 18, 3:02 PM MDT	Severe Thunderstorm Watch	SPC	Baca, Bent, Cheyenne, Crowley, El Paso, Huerfano and 6 more	7 hr

Nearby

Mesoscale Discussions in Colorado, 2018 Every mesoscale discussion 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.