Alert archive / Alabama / Flash Flood Watches in 2018

Flash Flood Watch 6, NWS Birmingham, AL

October 9, 20184 counties in Alabama

NWS Birmingham, AL issued this flash flood watch at Oct 9, 2018, 3:26 AM CDT for 4 counties in Alabama. It took effect at Oct 10, 2018, 11:00 AM CDT. It was in force for 14 hr.

The area

The counties it named.

The facts

Issued
Oct 9, 2018, 3:26 AM CDT (08:26 UTC)
In effect from
Oct 10, 2018, 11:00 AM CDT
Expired
Oct 11, 2018, 1:00 AM CDT
In force
14 hr
Issued by
NWS Birmingham, AL
Flood severity
None

Counties Barbour County, AL, Bullock County, AL, Pike County, AL, Russell County, AL

The radar

The Maxwell AFB radar (KMXX), 62 km from the middle of the area, began a volume at 08:29 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 8.4 hours before the alert went out and 180 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, Peachtre/Fal Fld, GA at 00:00Z on 2018-10-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 523 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, Peachtre/Fal Fld, GA at 00:00Z on 2018-10-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 square meters per square second.193958Sfc1 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
523 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1033 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.3

Open this sounding in Storm Lab

The office that day

Everything else NWS Birmingham, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 9, 4:31 AM CDTTropical Storm WatchBMXBarbour, Pike12 hr
Oct 9, 4:10 PM CDTTropical Storm WarningBMXBarbour, Bullock, Pike, Russell30 hr

Nearby

Flash Flood Watches in Alabama, 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.