Alert archive / North Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 15, NWS Raleigh, NC

August 7, 2021Guilford County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Aug 7, 2021, 9:28 AM EDT for Guilford County, North Carolina. It was in force for 81 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 7, 2021, 9:28 AM EDT (13:28 UTC)
Expired
Aug 7, 2021, 10:49 AM EDT
In force
81 min
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

County Guilford County, NC

The radar

The Roanoke radar (KFCX), 117 km from the middle of the area, began a volume at 13:31 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 12:00Z, 1.5 hours before the alert went out and 10 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, Greensboro/Hi Pt, NC at 12:00Z on 2021-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2021-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
17 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
543 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
67 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

736 
WGUS52 KRAH 071328
FFWRAH
NCC081-071530-
/O.NEW.KRAH.FF.W.0015.210807T1328Z-210807T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Raleigh NC
928 AM EDT Sat Aug 7 2021

The National Weather Service in Raleigh has issued a

* Flash Flood Warning for...
  Central Guilford County in central North Carolina...

* Until 1130 AM EDT.

* At 928 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Greensboro, High Point, McLeansville, Pleasant Garden, Jamestown, 
  Lake Jeanette Marina, Lake Townsend, Forest Oaks, Lake Brandt, 
  Lake Townsend Marina, Monticello and Oak Hollow Marina.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3594 8003 3607 8001 3622 7977 3621 7955
      3609 7957 3594 7972 3594 7973

FLASH FLOOD...RADAR INDICATED

$$
1 follow-up statement
970 
WGUS72 KRAH 071449
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
1049 AM EDT Sat Aug 7 2021

NCC081-071459-
/O.CAN.KRAH.FF.W.0015.000000T0000Z-210807T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Guilford NC-
1049 AM EDT Sat Aug 7 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL GUILFORD COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.

LAT...LON 3594 8003 3607 8001 3622 7977 3621 7955
      3609 7957 3594 7972 3594 7973

$$

The office that day

Everything else NWS Raleigh, NC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 6:22 AM EDTSpecial Weather StatementRAHAlamance, Guilford, Randolph53 min
Aug 7, 6:38 AM EDTSpecial Weather StatementRAHWayne, Wilson52 min
Aug 7, 8:05 AM EDTFlash Flood WarningRAHRandolph3 hr
Aug 7, 8:53 AM EDTAreal Flood AdvisoryRAHDavidson, Forsyth, Guilford, Randolph112 min
Aug 7, 10:14 AM EDTAreal Flood AdvisoryRAHDurham, Granville, Orange, Wake61 min
Aug 7, 11:41 AM EDTAreal Flood AdvisoryRAHFranklin, Vance, Warren64 min
Aug 7, 12:18 PM EDTSpecial Weather StatementRAHHalifax, Nash57 min
Aug 7, 6:21 PM EDTFlash Flood Warning Considerable damage threatRAHSampson, Wayne2 hr

Nearby

Flash Flood Warnings in North Carolina, 2021Every flash flood warning in 2021

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.