Alert archive / Mississippi / Mesoscale Discussions in 2018

Mesoscale Discussion 40

January 22, 2018Choctaw County, Washington County, Alabama; 4 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 22, 2018, 10:25 AM CST for Choctaw County, Washington County, Alabama; 4 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jan 22, 2018, 10:25 AM CST (16:25 UTC)
Expired
Jan 22, 2018, 12:30 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Choctaw County, AL, Washington County, AL, Clarke County, MS, Greene County, MS, Perry County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 112 km from the middle of the area, began a volume at 16:25 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

Jackson, MS (KJAN), launched 12:00Z, 4.4 hours before the alert went out and 158 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, Jackson, MS at 12:00Z on 2018-01-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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, Jackson, MS at 12:00Z on 2018-01-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 370 square meters per square second.1939587897117Sfc1 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
13 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
554 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
370 m²/s²
0-3 km storm-relative helicity
414 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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
Jan 22, 1:48 PM CSTMesoscale DiscussionSPCBarbour, Bullock, Butler, Crenshaw, Macon, Montgomery and 1 more2 hr

Nearby

Mesoscale Discussions in Mississippi, 2018Mesoscale Discussions in Alabama, 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.