Alert archive / North Carolina / Flash Flood Watches in 2018

Flash Flood Watch 4, NWS Greenville-Spartanburg, SC

May 17, 201813 counties in North Carolina; Rabun County, Georgia

NWS Greenville-Spartanburg, SC issued this flash flood watch at May 17, 2018, 3:50 AM EDT for 13 counties in North Carolina; Rabun County, Georgia. It was in force for 68 hr.

The area

The counties it named.

The facts

Issued: May 17, 2018, 3:50 AM EDT (07:50 UTC)
Expired: May 20, 2018, 12:00 AM EDT
In force: 68 hr
Issued by: NWS Greenville-Spartanburg, SC
Flood severity: None

Counties Rabun County, GA, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rutherford County, NC, Transylvania County, NC, Yancey County, NC

The radar

The Greer radar (KGSP), 74 km from the middle of the area, began a volume at 07:53 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.8 hours before the alert went out and 233 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: 137 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 909 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 42 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this flash flood watch went out at May 17, 3:42 AM EDT, 8 minutes earlier.

Area forecast discussion, May 17, 3:42 AM EDT, 8 minutes before

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Hazardous weather outlook, May 16, 6:17 PM EDT, 9 hours 33 minutes before

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In the hours before

Special weather statement, May 16, 11:02 PM EDT, 4 hours 48 minutes before

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Special weather statement, May 16, 11:31 PM EDT, 4 hours 19 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
May 16, 8:10 PM EDT	Areal Flood Advisory	GSP	Cabarrus, Rowan	89 min
May 16, 8:50 PM EDT	Areal Flood Advisory	GSP	Henderson	4 hr
May 16, 9:55 PM EDT	Areal Flood Advisory	GSP	Jackson, Macon, Transylvania	3 hr
May 16, 11:02 PM EDT	Special Weather Statement	GSP	Alexander	28 min
May 16, 11:31 PM EDT	Special Weather Statement	GSP	Avery	59 min
May 17, 1:01 AM EDT	Areal Flood Advisory	GSP	Transylvania	6 hr
May 17, 4:34 PM EDT	Special Weather Statement	GSP	Haywood	26 min
May 17, 4:40 PM EDT	Special Weather Statement	GSP	Caldwell	35 min
May 17, 5:06 PM EDT	Areal Flood Advisory	GSP	Burke, Caldwell	114 min
May 17, 6:44 PM EDT	Special Weather Statement	GSP	Swain	46 min
May 17, 7:26 PM EDT	Special Weather Statement	GSP	McDowell	49 min
May 17, 7:44 PM EDT	Areal Flood Advisory	GSP	McDowell, Rutherford	2 hr
May 17, 7:48 PM EDT	Special Weather Statement	GSP	Henderson	27 min
May 17, 7:52 PM EDT	Special Weather Statement	GSP	Macon	23 min
May 16, 8:12 PM EDT	Special Weather Statement	GSP	Cherokee	48 min

Nearby

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