Alert archive / Georgia / Mesoscale Discussions in 2017

Mesoscale Discussion 707

May 12, 20175 states

The Storm Prediction Center issued this mesoscale discussion at May 12, 2017, 1:06 PM CDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 12, 2017, 1:06 PM CDT (18:06 UTC)
Expired
May 12, 2017, 3:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 103 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Clay County, AL, Cleburne County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Marshall County, AL, Randolph County, AL, St. Clair County, AL, Talladega County, AL, Banks County, GA, Barrow County, GA, Bartow County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Haralson County, GA, Hart County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Lumpkin County, GA, Madison County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA, Buncombe County, NC, Burke County, NC, Cherokee County, NC, Clay County, NC, Cleveland County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rutherford County, NC, Swain County, NC, Transylvania County, NC, Yancey County, NC, Anderson County, SC, Greenville County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, Blount County, TN, Bradley County, TN, Cocke County, TN, Grundy County, TN, Hamilton County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Polk County, TN, Rhea County, TN, Sequatchie County, TN, Sevier County, TN

The radar

The Atlanta radar (KFFC), 151 km from the middle of the area, began a volume at 18:06 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 12:00Z, 6.1 hours before the alert went out and 148 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 12:00Z on 2017-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2017-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1299 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 12, 9:56 AM CDTMesoscale DiscussionSPCWashington3 hr
May 12, 10:35 AM CDTSevere Thunderstorm WatchSPCBaldwin, Escambia, Mobile5 hr
May 12, 10:56 AM CDTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Chilton, Clay and 16 more3 hr
May 12, 1:42 PM CDTMesoscale DiscussionSPCBaldwin, Barbour, Butler, Coffee, Conecuh, Covington and 8 more108 min
May 11, 9:12 PM CDTMesoscale DiscussionSPCBeaufort, Edgecombe, Franklin, Greene, Johnston, Lenoir and 6 more63 min
May 12, 5:33 PM CDTMesoscale DiscussionSPCBerkeley, Chester, Chesterfield, Clarendon, Darlington, Fairfield and 13 more2 hr

Nearby

Mesoscale Discussions in Georgia, 2017Mesoscale Discussions in North Carolina, 2017Mesoscale Discussions in Tennessee, 2017Every mesoscale discussion in 2017

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.