Alert archive / Arkansas / Mesoscale Discussions in 2020

Mesoscale Discussion 539

May 4, 20208 counties in Arkansas; 4 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 4, 2020, 9:29 PM CDT for 8 counties in Arkansas; 4 counties in Oklahoma. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
May 4, 2020, 9:29 PM CDT (02:29 UTC)
Expired
May 4, 2020, 10:30 PM CDT
In force
61 min
Issued by
the Storm Prediction Center

Counties Crawford County, AR, Franklin County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Newton County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Haskell County, OK, McIntosh County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 29 km from the middle of the area, began a volume at 02:32 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

Springfield, MO (KSGF), launched 00:00Z, 2.5 hours before the alert went out and 157 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, Springfield, MO at 00:00Z on 2020-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 135 joules per kilogram.LCLLFCEL10008507005003002001001 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, Springfield, MO at 00:00Z on 2020-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 436 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
135 J/kg
Mixed-layer CIN
-464 J/kg
Mixed-layer LCL
494 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
436 m²/s²
0-3 km storm-relative helicity
495 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.7

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 4, 11:54 PM CDTMesoscale DiscussionSPCConway, Faulkner, Logan, Lonoke, Perry, Pulaski and 2 more2 hr
May 4, 7:57 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Coal, Johnston, Love and 1 more2 hr

Nearby

Mesoscale Discussions in Arkansas, 2020Mesoscale Discussions in Oklahoma, 2020Every mesoscale discussion in 2020

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.