Alert archive / North Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 11, NWS Raleigh, NC

July 16, 2021Guilford County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jul 16, 2021, 1:44 PM EDT for Guilford County, North Carolina. It was in force for 80 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: Jul 16, 2021, 1:44 PM EDT (17:44 UTC)
Expired: Jul 16, 2021, 3:04 PM EDT
In force: 80 min
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Guilford County, NC

The radar

The Roanoke radar (KFCX), 113 km from the middle of the area, began a volume at 17:44 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, 5.7 hours before the alert went out and 9 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: 172 J/kg
Mixed-layer CIN: -79 J/kg
Mixed-layer LCL: 1372 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 71 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

766 
WGUS52 KRAH 161744
FFWRAH
NCC081-162030-
/O.NEW.KRAH.FF.W.0011.210716T1744Z-210716T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Raleigh NC
144 PM EDT Fri Jul 16 2021

The National Weather Service in Raleigh has issued a

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

* Until 430 PM EDT.

* At 144 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 2 inches of rain have fallen on 
  the northeastern side of Greensboro, east of US 29 and north of US 
  70. Lesser amounts of one half to one inch have fallen from near 
  and north of Jamestown and across the remainder of downtown 
  Greensboro. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Greensboro, High Point, McLeansville, Jamestown and Oak Hollow 
  Marina.

Buffalo Creek will rise rapidly and may exceed flood stage this 
afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3615 7975 3614 7962 3610 7959 3604 7963
      3604 7980 3598 7994 3602 8002 3607 8001
      3610 7990 3613 7982

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1 INCH IN 1 HOUR

$$

26

1 follow-up statement

718 
WGUS72 KRAH 161904
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
304 PM EDT Fri Jul 16 2021

NCC081-161914-
/O.CAN.KRAH.FF.W.0011.000000T0000Z-210716T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Guilford NC-
304 PM EDT Fri Jul 16 2021

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

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed any road closures.

LAT...LON 3615 7975 3614 7962 3610 7959 3604 7963
      3604 7980 3598 7994 3602 8002 3607 8001
      3610 7990 3613 7982

$$

26

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 1:32 PM EDT	Areal Flood Advisory	RAH	Guilford	92 min
Jul 16, 3:14 PM EDT	Special Weather Statement	RAH	Orange	31 min
Jul 16, 4:19 PM EDT	Special Weather Statement	RAH	Franklin, Nash	41 min
Jul 16, 4:59 PM EDT	Special Weather Statement	RAH	Harnett	46 min
Jul 16, 6:24 PM EDT	Special Weather Statement	RAH	Randolph	66 min
Jul 16, 6:53 PM EDT	Special Weather Statement	RAH	Franklin	67 min

Nearby

Flash Flood Warnings in North Carolina, 2021 Every 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.