Alert archive / North Carolina / Flash Flood Watches in 2020

Flash Flood Watch 7, NWS Greenville-Spartanburg, SC

May 18, 202022 counties in North Carolina; 5 counties in South Carolina

NWS Greenville-Spartanburg, SC issued this flash flood watch at May 18, 2020, 2:51 PM EDT for 22 counties in North Carolina; 5 counties in South Carolina. It took effect at May 18, 2020, 8:00 PM EDT. It was in force for 3 days.

The area

The counties it named.

The facts

Issued
May 18, 2020, 2:51 PM EDT (18:51 UTC)
In effect from
May 18, 2020, 8:00 PM EDT
Expired
May 21, 2020, 8:00 PM EDT
In force
3 days
Issued by
NWS Greenville-Spartanburg, SC
Flood severity
None
All 27 counties

Alexander County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Davie County, NC, Gaston County, NC, Henderson County, NC, Iredell County, NC, Lincoln County, NC, McDowell County, NC, Mecklenburg County, NC, Mitchell County, NC, Polk County, NC, Rowan County, NC, Rutherford County, NC, Transylvania County, NC, Union County, NC, Yancey County, NC, Anderson County, SC, Cherokee County, SC, Chester County, SC, Union County, SC, York County, SC

The radar

The Greer radar (KGSP), 86 km from the middle of the area, began a volume at 18:55 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

Roanoke, VA (KRNK), launched 12:00Z, 6.9 hours before the alert went out and 269 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, Roanoke, VA at 12:00Z on 2020-05-18Temperature 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, Roanoke, VA at 12:00Z on 2020-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
792 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
68 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 18, 2:45 PM EDT, 6 minutes earlier.

Area forecast discussion, May 18, 2:45 PM EDT, 6 minutes before
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Hazardous weather outlook, May 18, 6:42 AM EDT, 8 hours 9 minutes before
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In the hours before

Special weather statement, May 18, 9:55 AM EDT, 4 hours 56 minutes before
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Special weather statement, May 18, 1:40 PM EDT, 1 hour 11 minutes before
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Special weather statement, May 18, 2:14 PM EDT, 37 minutes before
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Special weather statement, May 18, 2:47 PM EDT, 4 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
May 18, 9:55 AM EDTSpecial Weather StatementGSPGreenville95 min
May 18, 2:14 PM EDTSpecial Weather StatementGSPAbbeville31 min
May 18, 2:47 PM EDTSpecial Weather StatementGSPGreenwood58 min
May 18, 3:26 PM EDTSpecial Weather StatementGSPGreenwood49 min
May 18, 4:48 PM EDTSpecial Weather StatementGSPLaurens42 min
May 18, 5:37 AM EDTSpecial Weather StatementGSPFranklin38 min
May 18, 1:40 PM EDTSpecial Weather StatementGSPElbert, Franklin, Hart65 min
May 18, 7:28 PM EDTSpecial Weather StatementGSPFranklin, Hart, Stephens47 min
May 18, 7:55 PM EDTSpecial Weather StatementGSPElbert50 min

Nearby

Flash Flood Watches in North Carolina, 2020Flash Flood Watches in South Carolina, 2020Every flash flood watch in 2020

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.