Alert archive / Mississippi / Flash Flood Watches in 2018

Flash Flood Watch 1, NWS Memphis, TN

April 12, 201821 counties in Tennessee; 22 counties in Mississippi; 12 counties in Arkansas

NWS Memphis, TN issued this flash flood watch at Apr 12, 2018, 2:34 PM CDT for 21 counties in Tennessee; 22 counties in Mississippi; 12 counties in Arkansas. It took effect at Apr 13, 2018, 10:00 PM CDT. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued: Apr 12, 2018, 2:34 PM CDT (19:34 UTC)
In effect from: Apr 13, 2018, 10:00 PM CDT
Expired: Apr 14, 2018, 2:33 PM CDT
In force: 17 hr
Issued by: NWS Memphis, TN
Flood severity: None

All 55 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lawrence County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, Randolph County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 42 km from the middle of the area, began a volume at 19:37 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

Little Rock, AR (KBYH), launched 12:00Z, 7.6 hours before the alert went out and 58 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2947 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 223 m²/s²
0-3 km storm-relative helicity: 257 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Memphis, TN wrote its last area forecast discussion before this flash flood watch went out at Apr 12, 12:57 PM CDT, 1 hour 37 minutes earlier.

Area forecast discussion, Apr 12, 12:57 PM CDT, 1 hour 37 minutes before

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Hazardous weather outlook, Apr 12, 4:57 AM CDT, 9 hours 37 minutes before

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</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.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

Everything else NWS Memphis, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 12, 3:46 AM CDT	Wind Advisory	MEG	Dyer, Lake, Lauderdale, Obion, Shelby, Tipton	16 hr
Apr 12, 10:57 AM CDT	River Flood Advisory	MEG	Lauderdale, Tipton	4 days
Apr 12, 2:26 PM CDT	Blowing Dust Advisory	MEG	Clay, Craighead, Cross, Greene, Lawrence, Mississippi and 2 more	6 hr

Nearby

Flash Flood Watches in Mississippi, 2018 Flash Flood Watches in Tennessee, 2018 Flash Flood Watches in Arkansas, 2018 Every flash flood watch 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.