Alert archive / Mississippi / Mesoscale Discussions in 2018

Mesoscale Discussion 141

March 19, 201817 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 19, 2018, 3:54 AM CDT for 17 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 19, 2018, 3:54 AM CDT (08:54 UTC)
Expired
Mar 19, 2018, 6:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Leflore County, MS, Lowndes County, MS, Montgomery County, MS, Noxubee County, MS, Oktibbeha County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS

The radar

The Columbus AFB radar (KGWX), 138 km from the middle of the area, began a volume at 08:55 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 (KBYH), launched 00:00Z, 8.9 hours before the alert went out and 121 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 00:00Z on 2018-03-19Temperature 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, Little Rock, AR at 00:00Z on 2018-03-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 280 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
634 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
280 m²/s²
0-3 km storm-relative helicity
406 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
Mar 19, 11:18 AM CDTMesoscale DiscussionSPCAlcorn, Prentiss, Tippah, Tishomingo, Union87 min
Mar 19, 2:06 PM CDTMesoscale DiscussionSPCAlcorn, Chickasaw, Clay, Itawamba, Lee, Lowndes and 7 more84 min
Mar 19, 3:28 PM CDTTornado Watch PDSSPCAlcorn, Calhoun, Chickasaw, Clay, Itawamba, Lee and 10 more9 hr

Nearby

Mesoscale Discussions in Mississippi, 2018Every 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.