Alert archive / Tennessee / Flash Flood Warnings in 2011

Flash Flood Warning 40, NWS Memphis, TN

April 11, 2011Shelby County, Tennessee

NWS Memphis, TN issued this flash flood warning at Apr 11, 2011, 1:54 PM CDT for Shelby County, Tennessee. It was in force for 80 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 11, 2011, 1:54 PM CDT (18:54 UTC)
Expired: Apr 11, 2011, 3:14 PM CDT
In force: 80 min
Issued by: NWS Memphis, TN
Area: Storm-based polygon
Flood severity: None

County Shelby County, TN

The radar

The Memphis radar (KNQA), 26 km from the middle of the area, began a volume at 18:57 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 (KLZK), launched 12:00Z, 6.9 hours before the alert went out and 33 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: 936 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 647 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 296 m²/s²
0-3 km storm-relative helicity: 322 m²/s²
Significant tornado parameter: 2.0
Supercell composite: 6.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

901 
WGUS54 KMEG 111854
FFWMEG
TNC157-112200-
/O.NEW.KMEG.FF.W.0040.110411T1854Z-110411T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MEMPHIS TN
154 PM CDT MON APR 11 2011

THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SHELBY COUNTY IN SOUTHWEST TENNESSEE...

* UNTIL 500 PM CDT

* AT 153 PM CDT...DOPPLER RADAR ESTIMATES 1 TO 3 INCHES OF RAINFALL
  HAS OCCURRED OVER THE PAST HOUR. SHOWERS AND THUNDERSTORMS WILL
  PRODUCE AN ADDITIONAL 1 TO 3 INCHES OF RAIN OVER THE NEXT 2 HOURS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BARTLETT...
  COLLIERVILLE...DOWNTOWN MEMPHIS...GERMANTOWN...MIDTOWN MEMPHIS...  
  MILLINGTON AND CORDOVA.

 THIS WARNING ALSO INCLUDES AREAS NEAR ROBCO LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

.EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF URBAN 
AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER DRAINAGE 
AREAS AND LOW LYING SPOTS.

.STAY TUNED TO THIS BROADCAST FOR THE LATEST UPDATES AND INFORMATION.
TO REPORT FLASH FLOODING ONLY...CALL 1 800 4 3 2 0 8 7 5.

&&

LAT...LON 3501 9023 3512 9006 3536 9005 3538 8965
      3501 8966 3501 9007

$$


TLSJR

1 follow-up statement

663 
WGUS74 KMEG 112014
FFSMEG

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MEMPHIS TN
314 PM CDT MON APR 11 2011

TNC157-112024-
/O.CAN.KMEG.FF.W.0040.000000T0000Z-110411T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SHELBY TN-
314 PM CDT MON APR 11 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SHELBY COUNTY...

THE HEAVY RAINFALL WHICH PROMPTED THE WARNING HAS DIMINISHED ACROSS
THE WARNED AREA. THUS THE FLASH FLOOD WARNING HAS BEEN CANCELLED.

.STAY TUNED TO THIS BROADCAST FOR THE LATEST UPDATES AND INFORMATION.
TO REPORT SEVERE WEATHER ONLY...CALL 1 800 4 3 2 0 8 7 5.

LAT...LON 3501 9023 3512 9006 3536 9005 3538 8965
      3501 8966 3501 9007

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 4:43 AM CDT	Wind Advisory	MEG	Carroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more	12 hr
Apr 11, 7:42 AM CDT	Severe Thunderstorm Warning	MEG	Dyer, Lauderdale, Tipton	48 min
Apr 11, 8:29 AM CDT	Severe Thunderstorm Warning	MEG	Crockett, Dyer, Gibson, Haywood, Lake, Lauderdale and 2 more	36 min
Apr 11, 12:27 PM CDT	River Flood Advisory	MEG	Dyer, Lake	3 days
Apr 11, 12:34 PM CDT	Flash Flood Warning	MEG	Lauderdale, Tipton	3 hr
Apr 11, 2:17 PM CDT	Flash Flood Warning	MEG	Dyer, Lauderdale, Obion	117 min
Apr 11, 2:43 PM CDT	Special Weather Statement	MEG	Crockett, Gibson, Madison	32 min
Apr 11, 3:45 PM CDT	Flash Flood Warning	MEG	Decatur	2 hr

Nearby

Flash Flood Warnings in Tennessee, 2011 Every flash flood warning in 2011

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.