Alert archive / Alabama / Mesoscale Discussions in 2018

Mesoscale Discussion 57

February 7, 20189 counties in Alabama; 5 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Feb 7, 2018, 7:43 AM CST for 9 counties in Alabama; 5 counties in Georgia. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Feb 7, 2018, 7:43 AM CST (13:43 UTC)
Expired
Feb 7, 2018, 8:45 AM CST
In force
62 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Bullock County, AL, Butler County, AL, Crenshaw County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Russell County, AL, Chattahoochee County, GA, Harris County, GA, Meriwether County, GA, Muscogee County, GA, Talbot County, GA

The radar

The Maxwell AFB radar (KMXX), 31 km from the middle of the area, began a volume at 13:46 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

Birmingham, AL (KBMX), launched 12:00Z, 1.7 hours before the alert went out and 131 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, Birmingham, AL at 12:00Z on 2018-02-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 743 joules per kilogram.LCLEL10008507005003002001001 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, Birmingham, AL at 12:00Z on 2018-02-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 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
743 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
422 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
517 m²/s²
Significant tornado parameter
2.2
Supercell composite
10.6

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
Feb 7, 11:04 AM CSTMesoscale DiscussionSPCDale, Geneva, Henry, Houston116 min

Nearby

Mesoscale Discussions in Alabama, 2018Mesoscale Discussions in Georgia, 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.