Alert archive / Colorado / Mesoscale Discussions in 2023

Mesoscale Discussion 813

May 18, 202310 counties in Colorado; Laramie County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at May 18, 2023, 12:30 PM MDT for 10 counties in Colorado; Laramie County, Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 18, 2023, 12:30 PM MDT (18:30 UTC)
Expired
May 18, 2023, 2:30 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Lincoln County, CO, Morgan County, CO, Washington County, CO, Weld County, CO, Laramie County, WY

The radar

The Denver radar (KFTG), 50 km from the middle of the area, began a volume at 18:31 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 6.5 hours before the alert went out and 329 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, N. Platte/Lee Bi, NE at 12:00Z on 2023-05-18Temperature 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, N. Platte/Lee Bi, NE at 12:00Z on 2023-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 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
873 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
64 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
May 18, 4:18 PM MDTMesoscale DiscussionSPCLogan, Washington, Yuma87 min

Nearby

Mesoscale Discussions in Colorado, 2023Mesoscale Discussions in Wyoming, 2023Every mesoscale discussion in 2023

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.