Alert archive / Georgia / Mesoscale Discussions in 2018

Mesoscale Discussion 151

March 19, 2018Cleburne County, Alabama; 5 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 19, 2018, 8:51 PM CDT for Cleburne County, Alabama; 5 counties in Georgia. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Mar 19, 2018, 8:51 PM CDT (01:51 UTC)
Expired
Mar 19, 2018, 10:15 PM CDT
In force
84 min
Issued by
the Storm Prediction Center

Counties Cleburne County, AL, Carroll County, GA, Douglas County, GA, Haralson County, GA, Paulding County, GA, Polk County, GA

The radar

The Atlanta radar (KFFC), 68 km from the middle of the area, began a volume at 01:55 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 1.9 hours before the alert went out and 72 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, Peachtre/Fal Fld, GA at 00:00Z on 2018-03-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 184 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, Peachtre/Fal Fld, GA at 00:00Z on 2018-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 157 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
184 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
630 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
157 m²/s²
0-3 km storm-relative helicity
258 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

519 
ACUS11 KWNS 200152
SWOMCD
SPC MCD 200151 
GAZ000-ALZ000-200315-

Mesoscale Discussion 0151
NWS Storm Prediction Center Norman OK
0851 PM CDT Mon Mar 19 2018

Areas affected...Northeast AL/northwest GA border

Concerning...Tornado Watch 15...

Valid 200151Z - 200315Z

The severe weather threat for Tornado Watch 15 continues.

SUMMARY...Threat for significant tornadoes with supercell cluster
near the AL/GA border will continue for another 1-2 hours.

DISCUSSION...Recent radar imagery confirms additional supercell
development and rapid intensification of rotation with storms on the
south flank of the long-lived supercell cluster that has crossed AL
during the evening.  This newer development initially suffered less
destructive interference compared to earlier storms, and low-level
hodographs have become more favorable for low-level rotation/strong
tornadoes per regional VWPs.  The more moist environment near the
AL/GA border may offset the storm interactions and maintain a
significant tornado threat for another 1-2 hours as the storms
spread into GA.

..Thompson.. 03/20/2018

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

ATTN...WFO...FFC...BMX...

LAT...LON   34088507 33948476 33788465 33508468 33408477 33418514
            33558544 33688567 33888568 34098539 34088507

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 19, 10:18 PM CDTMesoscale DiscussionSPCClay, Cleburne, Randolph57 min
Mar 19, 7:45 PM CDTMesoscale DiscussionSPCBaldwin, Bartow, Bibb, Butts, Carroll, Chattooga and 40 more60 min
Mar 19, 8:08 PM CDTTornado WatchSPCBaldwin, Barrow, Bartow, Bibb, Butts, Carroll and 48 more7 hr
Mar 19, 11:32 PM CDTMesoscale DiscussionSPCBulloch, Burke, Candler, Columbia, Effingham, Jenkins and 2 more88 min
Mar 20, 12:51 AM CDTSevere Thunderstorm WatchSPCBryan, Bulloch, Burke, Candler, Chatham, Columbia and 16 more4 hr
Mar 20, 1:36 AM CDTMesoscale DiscussionSPCBaldwin, Bibb, Crawford, Glascock, Harris, Jefferson and 12 more84 min
Mar 20, 3:54 AM CDTMesoscale DiscussionSPCBryan, Bulloch, Candler, Chatham, Effingham, Emanuel and 12 more96 min
Mar 20, 8:50 AM CDTMesoscale DiscussionSPCCamden, Charlton55 min
Mar 20, 9:24 AM CDTTornado WatchSPCCamden, Charlton9 hr
Mar 20, 11:05 AM CDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 23 more55 min
Mar 20, 11:43 AM CDTTornado WatchSPCAppling, Bacon, Brantley, Bryan, Bulloch, Charlton and 13 more7 hr
Mar 20, 12:00 PM CDTMesoscale DiscussionSPCCamden, Charlton, Echols60 min
Mar 20, 1:48 PM CDTMesoscale DiscussionSPCBrantley, Bryan, Camden, Charlton, Chatham, Clinch and 9 more87 min
Mar 20, 3:16 PM CDTMesoscale DiscussionSPCCamden, Charlton, Echols89 min
Mar 20, 5:10 PM CDTMesoscale DiscussionSPCChatham, Glynn, McIntosh65 min

Nearby

Mesoscale Discussions in Georgia, 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.