Alert archive / Georgia / Mesoscale Discussions in 2016

Mesoscale Discussion 320

March 31, 201620 counties in Alabama; 49 counties in Georgia; 7 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2016, 10:11 PM CDT for 20 counties in Alabama; 49 counties in Georgia; 7 counties in Tennessee. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Mar 31, 2016, 10:11 PM CDT (03:11 UTC)
Expired
Mar 31, 2016, 11:15 PM CDT
In force
64 min
Issued by
the Storm Prediction Center
All 76 counties

Autauga County, AL, Bullock County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Cleburne County, AL, Coosa County, AL, Dallas County, AL, DeKalb County, AL, Elmore County, AL, Etowah County, AL, Jackson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Montgomery County, AL, Randolph County, AL, Russell County, AL, Tallapoosa County, AL, Bartow County, GA, Bibb County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattahoochee County, GA, Chattooga County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, Dade County, GA, Dooly County, GA, Douglas County, GA, Fayette County, GA, Floyd County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jones County, GA, Lamar County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Murray County, GA, Muscogee County, GA, Paulding County, GA, Peach County, GA, Pike County, GA, Polk County, GA, Pulaski County, GA, Schley County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taylor County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA, Walker County, GA, Webster County, GA, Whitfield County, GA, Bradley County, TN, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Marion County, TN, Polk County, TN, Sequatchie County, TN

The radar

The Atlanta radar (KFFC), 81 km from the middle of the area, began a volume at 03:11 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, 3.2 hours before the alert went out and 87 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 2016-04-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 138 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 2016-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 260 square meters per square second.1939587897117136Sfc1 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
138 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
960 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
260 m²/s²
0-3 km storm-relative helicity
286 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.0

Open this sounding in Storm Lab

The text

As transmitted.

985 
ACUS11 KWNS 010311
SWOMCD
SPC MCD 010311 
GAZ000-TNZ000-ALZ000-010415-

MESOSCALE DISCUSSION 0320
NWS STORM PREDICTION CENTER NORMAN OK
1011 PM CDT THU MAR 31 2016

AREAS AFFECTED...WRN/CNTRL GA...CNTRL/ERN AL...SERN TN

CONCERNING...TORNADO WATCH 72...73...

VALID 010311Z - 010415Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 72...73...CONTINUES.

SUMMARY...TRANSIENT MESOCYCLONES SHOULD POSE A LOW-PROBABILITY
TORNADO/WIND RISK DURING THE NEXT FEW HOURS AS AN MCS EVOLVES FROM
PARTS OF AL/FAR SERN TN INTO WRN GA.

DISCUSSION...A MESSY CLUSTER CONVECTIVE MODE HAS BECOME PREDOMINANT
WITH AN MCS GRADUALLY SHIFTING E FROM THE TN VALLEY. AREA VWP DATA
HAVE SAMPLED STRENGTHENING LOW-LEVEL WINDS BUT INCREASINGLY VEERED
FLOW /SWLYS/ AS WELL. OVER THE NEXT FEW HOURS...THE LOW-LEVEL
HODOGRAPH SHOULD STILL REMAIN CONDUCIVE TO TRANSIENT MESOCYCLONES.
WHERE SURFACE DEW POINTS ARE IN THE MIDDLE 60S OR GREATER...ROUGHLY
BOUNDED TO THE EAST BY THE WRN ATLANTA METRO TO MACON AREA AS OF 
03Z...A BRIEF TORNADO RISK WILL REMAIN PRESENT. IT APPEARS THIS MAY
BECOME CONFINED TO MAINLY E-CNTRL AL/W-CNTRL GA GIVEN A
COMPARATIVELY RICHER FEED OF LOW-LEVEL MOISTURE. FARTHER N ALONG THE
TN/AL/GA BORDER...THE ABUNDANT OVERTURNING ALONG WITH A PINCHED-OFF
SURFACE-BASED WARM SECTOR SUGGESTS THE TORNADO THREAT SHOULD SLOWLY
WANE.

..GRAMS.. 04/01/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MRX...FFC...TAE...OHX...BMX...HUN...

LAT...LON   35118621 35408573 35498526 35308454 34818439 34288462
            33628425 33038353 32478332 32038361 31978425 31958510
            32038604 32118665 32308718 32458719 32878679 33048639
            33088562 33408561 34018610 34368630 35118621

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 31, 7:41 PM CDTMesoscale DiscussionSPCCalhoun, Chambers, Cherokee, Clay, Cleburne, DeKalb and 6 more94 min
Mar 31, 8:14 PM CDTTornado WatchSPCBarbour, Bullock, Calhoun, Chambers, Cherokee, Clay and 8 more18 hr
Apr 1, 2:03 AM CDTMesoscale DiscussionSPCAutauga, Bullock, Dallas, Elmore, Lee, Lowndes and 5 more57 min
Apr 1, 4:46 AM CDTMesoscale DiscussionSPCBarbour, Bullock, Coffee, Crenshaw, Dale, Henry and 2 more89 min
Apr 1, 6:26 AM CDTTornado WatchSPCCoffee, Dale, Geneva, Henry, Houston12 hr
Apr 1, 10:40 AM CDTMesoscale DiscussionSPCBarbour, Coffee, Dale, Geneva, Henry, Houston and 2 more2 hr
Apr 1, 1:00 PM CDTMesoscale DiscussionSPCHenry, Houston60 min
Mar 31, 7:09 PM CDTMesoscale DiscussionSPCBrooks, Colquitt, Cook, Decatur, Grady, Lowndes and 3 more96 min
Apr 1, 12:31 AM CDTMesoscale DiscussionSPCBaldwin, Bleckley, Burke, Columbia, Dodge, Elbert and 18 more89 min
Apr 1, 1:48 PM CDTTornado WatchSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 50 more6 hr
Apr 1, 4:40 PM CDTMesoscale DiscussionSPCBrantley, Bryan, Camden, Charlton, Chatham, Clinch and 9 more65 min

Nearby

Mesoscale Discussions in Georgia, 2016Mesoscale Discussions in Alabama, 2016Mesoscale Discussions in Tennessee, 2016Every mesoscale discussion in 2016

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.