Alert archive / Arkansas / Flash Flood Watches in 2018

Flash Flood Watch 4, NWS Memphis, TN

September 6, 201812 counties in Arkansas

NWS Memphis, TN issued this flash flood watch at Sep 6, 2018, 3:36 PM CDT for 12 counties in Arkansas. It took effect at Sep 6, 2018, 10:00 PM CDT. It was in force for 30 hr.

The area

The counties it named.

The facts

Issued
Sep 6, 2018, 3:36 PM CDT (20:36 UTC)
In effect from
Sep 6, 2018, 10:00 PM CDT
Expired
Sep 8, 2018, 3:44 AM CDT
In force
30 hr
Issued by
NWS Memphis, TN
Flood severity
None

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

The radar

The Memphis radar (KNQA), 75 km from the middle of the area, began a volume at 20:39 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, 8.6 hours before the alert went out and 104 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, Little Rock, AR at 12:00Z on 2018-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 276 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, Little Rock, AR at 12:00Z on 2018-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 square meters per square second.1939Sfc1 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
276 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
455 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 2:07 PM CDTSpecial Weather StatementMEGCarroll38 min
Sep 6, 2:31 AM CDTAreal Flood AdvisoryMEGQuitman, Tallahatchie3 hr
Sep 6, 7:54 AM CDTAreal Flood AdvisoryMEGTallahatchie, Yalobusha3 hr
Sep 6, 11:08 AM CDTAreal Flood AdvisoryMEGLafayette, Panola, Yalobusha112 min
Sep 6, 1:03 PM CDTAreal Flood AdvisoryMEGLafayette, Panola, Yalobusha3 hr

Nearby

Flash Flood Watches in Arkansas, 2018Every 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.