Alert archive / Tennessee / Flash Flood Watches in 2015

Flash Flood Watch 9, NWS Memphis, TN

July 7, 201510 counties in Tennessee; 7 counties in Arkansas

NWS Memphis, TN issued this flash flood watch at Jul 7, 2015, 3:53 PM CDT for 10 counties in Tennessee; 7 counties in Arkansas. It took effect at Jul 7, 2015, 4:00 PM CDT. It was in force for 14 hr.

The area

The counties it named.

The facts

Issued: Jul 7, 2015, 3:53 PM CDT (20:53 UTC)
In effect from: Jul 7, 2015, 4:00 PM CDT
Expired: Jul 8, 2015, 5:37 AM CDT
In force: 14 hr
Issued by: NWS Memphis, TN
Flood severity: None

Counties Clay County, AR, Craighead County, AR, Greene County, AR, Lawrence County, AR, Mississippi County, AR, Poinsett County, AR, Randolph County, AR, Benton County, TN, Carroll County, TN, Crockett County, TN, Dyer County, TN, Gibson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 83 km from the middle of the area, began a volume at 20:53 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, 8.9 hours before the alert went out and 140 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: 430 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 838 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -59 m²/s²
0-3 km storm-relative helicity: -18 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 Jul 7, 3:48 PM CDT, 5 minutes earlier.

Area forecast discussion, Jul 7, 3:48 PM CDT, 5 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
348 PM CDT TUE JUL 7 2015

.DISCUSSION...

A HEAVY RAIN AND FLASH FLOOD THREAT SHOULD DEVELOP THIS EVENING
ACROSS PORTIONS OF NORTHEAST ARKANSAS...THE MISSOURI
BOOTHEEL...AND FAR NORTHWEST TENNESSEE. A FLASH FLOOD WATCH WILL
BE ISSUED FOR THESE AREAS BEGINNING THIS AFTERNOON AND EXTENDING
THROUGH EARLY WEDNESDAY AFTERNOON.

SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP SOUTHEAST ALONG
OUTFLOW FROM EARLIER CONVECTION TO THE NORTH OVER MISSOURI. THIS
BOUNDARY WILL LIKELY BE THE NEW FOCUS FOR TRAINING THUNDERSTORMS
WITH THE THREAT FOR VERY HEAVY RAINFALL. PRECIPITABLE WATER VALUES
IN THESE AREAS ARE PROGGED BY MODEL GUIDANCE TO EXCEED 2.25
INCHES. IN ADDITION...LIFT SHOULD BE ENHANCED ALONG THIS BOUNDARY
AS A LOW LEVEL JET STRENGTHENS AND NOSES INTO BOUNDARY IN RESPONSE
TO A SHORTWAVE LIFTING NORTHEASTWARD OUT OF TEXAS. THIS SCENARIO
SHOULD POSE A THREAT FOR HEAVY RAINFALL AND FLASH FLOODING IN
THESE AREAS INTO WEDNESDAY MORNING...BEFORE REFOCUSING FURTHER
NORTH ALONG A RETREATING SYNOPTIC WARM FRONT DURING THE DAY AS
THE SHORTWAVE AND ASSOCIATED SURFACE LOW LIFT FURTHER NORTHEAST
INTO THE MIDDLE MISSISSIPPI VALLEY. RAINFALL AMOUNTS IN THE FLASH
FLOOD WATCH AREA SHOULD RANGE BETWEEN 2 AND 4 INCHES...WITH
ISOLATED HIGHER AMOUNTS. THESE AMOUNTS HAVE BEEN COORDINATED WITH
HPC AND SURROUNDING OFFICES AND ALIGN WELL WITH THE HPC MODERATE
RISK FOR EXCESSIVE RAINFALL.

SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN COVERAGE LATER
WEDNESDAY MORNING WITH REDEVELOPMENT OF SCATTERED COVERAGE OF
STORMS AS THE ATMOSPHERE DESTABILIZES WEDNESDAY AFTERNOON MAINLY
ACROSS NORTHERN AREAS. A STRONG STORM OR TWO CANNOT BE RULED OUT
AS OVERALL SHEAR REMAINS STRONG AND MLCAPES EXCEED 1500 J/KG.
OVERALL WEAK MID LEVEL LAPSE RATES SHOULD LIMIT A MORE WIDESPREAD
SEVERE EVENT. TEMPERATURES SHOULD WARM BACK INTO THE UPPER 80S
NORTH TO LOWER 90S SOUTH. HUMID CONDITIONS SHOULD ALSO CONTINUE
AREAWIDE AS THE MID SOUTH REMAINS WELL ENTRENCHED IN THE WARM
SECTOR.

UPPER LEVEL RIDGING WILL BUILD BACK INTO THE MID SOUTH FROM THE
EAST BY THURSDAY AND REMAIN IN PLACE ACROSS THE REGION THROUGH THE
WEEKEND. THIS SHOULD LEAD TO HOTTER AND DRIER CONDITIONS
OVERALL...BUT THERE MAY STILL BE ISOLATED AFTERNOON CONVECTION
ACROSS SOUTHERN AND EASTERN SECTIONS FRIDAY AND SATURDAY. THIS
OCCURS AS THE RIDGE RETROGRADES WEST AND SLIGHTLY LOWER MID LEVEL
HEIGHTS SPREAD BACK OVER THESE AREAS. HEAT INDICES WILL ALSO CREEP
BACK UP TO BETWEEN 100-105 WHICH WILL MAKE FOR UNCOMFORTABLE
CONDITIONS. CONDITIONS WILL BE WATCH FOR POSSIBLE HEAT
ADVISORY...BUT AT THIS TIME APPEARS TO REMAIN BELOW CRITERIA.

THE RETROGRADING UPPER RIDGE SHOULD EVENTUALLY BREAK DOWN ALONG
ITS EASTERN PERIPHERY AND OVER THE EASTERN HALF OF OUR FORECAST
AREA BY EARLY NEXT WEEK. THIS WILL ALLOW FOR THE NORTHWEST FLOW TO
SET UP AGAIN WITH A SERIES OF SHORTWAVES MOVING THROUGH THE FLOW.
THIS WILL HELP TO INCREASE CHANCES FOR SHOWERS AND THUNDERSTORMS
AND ALSO PROVIDE SLIGHTLY COOLER BUT STILL HUMID WEATHER
CONDITIONS.

&&

.AVIATION...

18Z TAF CYCLE

VFR CONDITIONS ARE EXPECTED ACROSS MOST TAF SITES TODAY.
HOWEVER...DURING THE AFTERNOON HOURS...VCTS SHOULD DEVELOP AT
JBR...MEM AND MKL. JBR STANDS THE BEST CHANCE OF LONGER DURATION
TSRA PERHAPS ALSO REDUCING VISIBILITIES TO NEAR 4SM. WINDS HAVE
ALSO INCREASED ABOVE 10 KTS AREA-WIDE WITH GUSTS NEAR 20 KTS FROM
THE SOUTHWEST. THESE WINDS SHOULD REMAIN STRONG THROUGH THE DAY
WITH THE MAINTENANCE OF THE LOW-LEVEL JET. WINDS ARE EXPECTED TO
SUBSIDE TONIGHT...INCREASING ONCE AGAIN ON WEDNESDAY TO SIMILAR
VALUES.

TVT

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR CLAY-GREENE-
     LAWRENCE-RANDOLPH.

MO...FLASH FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR DUNKLIN-
     PEMISCOT.

MS...NONE.
TN...FLASH FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR LAKE-OBION.

&&

Hazardous weather outlook, Jul 7, 5:08 AM CDT, 10 hours 45 minutes before

<!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>

In the hours before

Local storm report, Jul 7, 10:03 AM CDT, 5 hours 50 minutes before

<!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>

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 8:50 PM CDT	Flash Flood Warning	MEG	Craighead, Cross, Poinsett	3 hr
Jul 7, 5:16 PM CDT	Flash Flood Warning	MEG	Clay, Craighead, Greene, Lawrence, Randolph	3 hr

Nearby

Flash Flood Watches in Tennessee, 2015 Flash Flood Watches in Arkansas, 2015 Every flash flood watch in 2015

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.