Alert archive / Alabama / Mesoscale Discussions in 2022

Mesoscale Discussion 13

January 1, 202225 counties in Alabama; 13 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 1, 2022, 6:02 PM CST for 25 counties in Alabama; 13 counties in Mississippi. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
Jan 1, 2022, 6:02 PM CST (00:02 UTC)
Expired
Jan 1, 2022, 8:00 PM CST
In force
118 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 4...5...6
All 38 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lawrence County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Itawamba County, MS, Kemper County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Webster County, MS, Winston County, MS

The radar

The Columbus AFB radar (KGWX), 82 km from the middle of the area, began a volume at 00:02 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 0.0 hours before the alert went out and 94 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 00:00Z on 2022-01-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 227 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, Birmingham, AL at 00:00Z on 2022-01-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 362 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
227 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
362 m²/s²
0-3 km storm-relative helicity
462 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.6

Open this sounding in Storm Lab

The text

As transmitted.

058 
ACUS11 KWNS 020002
SWOMCD
SPC MCD 020002 
ALZ000-MSZ000-020200-

Mesoscale Discussion 0013
NWS Storm Prediction Center Norman OK
0602 PM CST Sat Jan 01 2022

Areas affected...parts of eastern MS and northern to west-central AL

Concerning...Tornado Watch 4...5...6...

Valid 020002Z - 020200Z

The severe weather threat for Tornado Watch 4, 5, 6 continues.

SUMMARY...The Risk of a few tornadoes, damaging wind gusts, and
isolated large hail may increase during the next few hours.

DISCUSSION...A mix of multicell clusters and transient supercell
structures should continue tracking east-northeastward from eastern
MS across parts of northern to west-central AL during the next few
hours. Here, a moist airmass (middle/upper 60s dewpoints) is
contributing to around 1000 J/kg MLCAPE where the latest VWPs show
0-6 km bulk shear of 60-70 knots. While storms have struggled across
the warm sector thus far owing to limited large-scale forcing for
ascent and weak low-level convergence, a low-level jet is expected
to overspread the area which may support a few longer-lived
multicell clusters and supercells over the next few hours. The
latest VWPs from GWX and HTX show 0-1 km SRH values of 250-300 m2/s2
ahead of the ongoing convection, which will support a risk of a few
tornadoes, damaging wind gusts, and isolated large hail with any
sustained supercells or intense multicells across the area.

..Weinman.. 01/02/2022

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

ATTN...WFO...BMX...HUN...MEG...JAN...

LAT...LON   34678721 34658632 34558567 34368548 34008557 33458602
            32808714 32378807 32538918 33098949 33618944 34188906
            34578833 34678721

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 1, 6:53 PM CSTTornado WatchSPCCullman, DeKalb, Franklin, Jackson, Lawrence, Limestone and 3 more7 hr
Jan 1, 8:30 PM CSTMesoscale DiscussionSPCJackson60 min
Jan 1, 9:11 PM CSTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Cullman, DeKalb and 17 more64 min
Jan 1, 10:07 PM CSTTornado WatchSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 25 more6 hr
Jan 1, 11:19 PM CSTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Chilton, Choctaw and 17 more116 min
Jan 2, 2:19 AM CSTMesoscale DiscussionSPCAutauga, Bibb, Calhoun, Chambers, Chilton, Choctaw and 17 more116 min
Jan 2, 10:37 AM CSTMesoscale DiscussionSPCCoffee, Covington, Dale, Geneva, Henry, Houston83 min
Jan 2, 12:53 PM CSTMesoscale DiscussionSPCCoffee, Dale, Geneva, Henry, Houston2 hr
Jan 2, 1:17 PM CSTTornado WatchSPCGeneva, Henry, Houston9 hr

Nearby

Mesoscale Discussions in Alabama, 2022Mesoscale Discussions in Mississippi, 2022Every mesoscale discussion in 2022

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.