Alert archive / North Carolina / Flash Flood Watches in 2018

Flash Flood Watch 1, NWS Greenville-Spartanburg, SC

February 28, 20184 counties in North Carolina; Rabun County, Georgia

NWS Greenville-Spartanburg, SC issued this flash flood watch at Feb 28, 2018, 3:35 AM EST for 4 counties in North Carolina; Rabun County, Georgia. It took effect at Feb 28, 2018, 1:00 PM EST. It was in force for 27 hr.

The area

The counties it named.

The facts

Issued
Feb 28, 2018, 3:35 AM EST (08:35 UTC)
In effect from
Feb 28, 2018, 1:00 PM EST
Expired
Mar 1, 2018, 3:54 PM EST
In force
27 hr
Issued by
NWS Greenville-Spartanburg, SC
Flood severity
None

Counties Rabun County, GA, Graham County, NC, Jackson County, NC, Macon County, NC, Swain County, NC

The radar

The Knoxville radar (KMRX), 104 km from the middle of the area, began a volume at 08:39 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 8.6 hours before the alert went out and 228 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 2018-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2018-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1883 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 28, 2:55 PM ESTHigh Wind WatchGSPAvery, Buncombe, Burke, Caldwell, Graham, Haywood and 11 more13 hr

Nearby

Flash Flood Watches in North Carolina, 2018Flash Flood Watches in Georgia, 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.