Alert archive / Mississippi / Flash Flood Watches in 2018

Flash Flood Watch 3, NWS Memphis, TN

September 4, 20186 counties in Mississippi; 6 counties in Arkansas

NWS Memphis, TN issued this flash flood watch at Sep 4, 2018, 2:19 PM CDT for 6 counties in Mississippi; 6 counties in Arkansas. It took effect at Sep 5, 2018, 7:00 AM CDT. It was in force for 39 hr.

The area

The counties it named.

The facts

Issued
Sep 4, 2018, 2:19 PM CDT (19:19 UTC)
In effect from
Sep 5, 2018, 7:00 AM CDT
Expired
Sep 6, 2018, 9:54 PM CDT
In force
39 hr
Issued by
NWS Memphis, TN
Flood severity
None

Counties Craighead County, AR, Cross County, AR, Lee County, AR, Phillips County, AR, Poinsett County, AR, St. Francis County, AR, Coahoma County, MS, Panola County, MS, Quitman County, MS, Tallahatchie County, MS, Tunica County, MS, Yalobusha County, MS

The radar

The Memphis radar (KNQA), 89 km from the middle of the area, began a volume at 19:20 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

Birmingham, AL (KBMX), launched 12:00Z, 7.3 hours before the alert went out and 379 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, Birmingham, AL at 12:00Z on 2018-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 179 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, Birmingham, AL at 12:00Z on 2018-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -97 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
179 J/kg
Mixed-layer CIN
-131 J/kg
Mixed-layer LCL
947 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-97 m²/s²
0-3 km storm-relative helicity
-75 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.8

Open this sounding in Storm Lab

Nearby

Flash Flood Watches in Mississippi, 2018Flash 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.