Alert archive / Arkansas / Mesoscale Discussions in 2021

Mesoscale Discussion 529

May 4, 202123 counties in Arkansas

The Storm Prediction Center issued this mesoscale discussion at May 4, 2021, 1:59 PM CDT for 23 counties in Arkansas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 4, 2021, 1:59 PM CDT (18:59 UTC)
Expired
May 4, 2021, 4:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 23 counties

Cleburne County, AR, Conway County, AR, Craighead County, AR, Cross County, AR, Faulkner County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Lonoke County, AR, Perry County, AR, Poinsett County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR

The radar

The Little Rock radar (KLZK), 72 km from the middle of the area, began a volume at 18:58 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

Little Rock, AR (KLZK), launched 12:00Z, 7.0 hours before the alert went out and 199 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, Little Rock, AR at 12:00Z on 2021-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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, Little Rock, AR at 12:00Z on 2021-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939587897Sfc1 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
10 J/kg
Mixed-layer CIN
-373 J/kg
Mixed-layer LCL
1101 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

960 
ACUS11 KWNS 041859
SWOMCD
SPC MCD 041859 
ARZ000-042100-

Mesoscale Discussion 0529
NWS Storm Prediction Center Norman OK
0159 PM CDT Tue May 04 2021

Areas affected...North-Central/Northeast AR

Concerning...Severe potential...Watch unlikely 

Valid 041859Z - 042100Z

Probability of Watch Issuance...20 percent

SUMMARY...A few strong storms are possible along the front as it
moves across north-central and northeast AR.

DISCUSSION...Recent surface analysis places a low about 30 miles
north-northwest of RUE in north-central AR. A cold front extends
northeastward from this low through southeast MO and southern IL,
and southward from the low across western AR. Modest instability
exists ahead of this front and attendant low, which could lead to
isolated thunderstorm development along the front as it continues
southeastward. Strong vertical shear is also in place, the potential
exists for a strong storm or two. However, progressive nature of the
front suggests likely undercutting of any storms that do develop,
limiting both severity and longevity.

..Mosier/Grams.. 05/04/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...MEG...LZK...

LAT...LON   35429332 36249223 36439056 35459023 34669133 34519300
            35429332

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 3, 8:38 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Boone, Calhoun, Carroll, Clark and 60 more2 hr
May 3, 9:10 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Calhoun, Carroll, Clark and 50 more7 hr
May 3, 10:22 PM CDTMesoscale DiscussionSPCBoone, Crawford, Franklin, Johnson, Madison, Marion and 2 more83 min
May 3, 11:34 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clark, Cleburne, Conway and 27 more86 min
May 4, 1:06 AM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Jackson and 5 more114 min
May 4, 1:41 AM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Mississippi and 2 more6 hr
May 4, 2:02 AM CDTMesoscale DiscussionSPCClay, Conway, Craighead, Cross, Faulkner, Garland and 16 more88 min
May 4, 4:17 AM CDTMesoscale DiscussionSPCCrittenden88 min
May 4, 6:44 AM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 8 more2 hr
May 4, 10:52 AM CDTTornado WatchSPCAshley, Bradley, Calhoun, Chicot, Columbia, Desha and 2 more7 hr
May 4, 11:58 AM CDTMesoscale DiscussionSPCCrittenden, Lee, Phillips2 hr
May 4, 12:18 PM CDTSevere Thunderstorm WatchSPCPhillips5 hr

Nearby

Mesoscale Discussions in Arkansas, 2021Every mesoscale discussion in 2021

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.