Alert archive / North Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 18, NWS Raleigh, NC

August 14, 2021Chatham County, Durham County, Wake County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Aug 14, 2021, 3:25 PM EDT for Chatham County, Durham County, Wake County, North Carolina. It was in force for 3 hr. 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 14, 2021, 3:25 PM EDT (19:25 UTC)
Expired
Aug 14, 2021, 6:07 PM EDT
In force
3 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Chatham County, NC, Durham County, NC, Wake County, NC

The radar

The Raleigh/Durham radar (KRAX), 35 km from the middle of the area, began a volume at 19:25 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, 7.4 hours before the alert went out and 100 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 2021-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1624 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 2021-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
1624 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
954 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

926 
WGUS52 KRAH 141925
FFWRAH
NCC037-063-183-142230-
/O.NEW.KRAH.FF.W.0018.210814T1925Z-210814T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Raleigh NC
325 PM EDT Sat Aug 14 2021

The National Weather Service in Raleigh has issued a

* Flash Flood Warning for...
  Southeastern Chatham County in central North Carolina...
  Southeastern Durham County in central North Carolina...
  Western Wake County in central North Carolina...

* Until 630 PM EDT.

* At 325 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to 2 inches of rain have 
  fallen. 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...
  Raleigh, Durham, Cary, Wake Forest, RDU International, Apex, Holly 
  Springs, Morrisville, Research Triangle, William B Umstead State 
  Park, Carpenter, Bethesda, New Hill, Jordan Lake, Falls Lake and 
  Falls Lake State Rec Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3563 7908 3577 7904 3587 7891 3604 7881
      3607 7876 3607 7868 3598 7844 3584 7867
      3568 7879 3565 7879 3556 7886 3558 7891
      3554 7902 3555 7903

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

10
3 follow-up statements
699 
WGUS72 KRAH 142005
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
405 PM EDT Sat Aug 14 2021

NCC037-142015-
/O.CAN.KRAH.FF.W.0018.000000T0000Z-210814T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chatham NC-
405 PM EDT Sat Aug 14 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN CHATHAM 
COUNTY...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 3587 7891 3604 7881 3607 7876 3607 7868
      3599 7848 3584 7867 3568 7879 3565 7879
      3561 7882 3561 7900 3584 7891

$$

NCC063-183-142230-
/O.CON.KRAH.FF.W.0018.000000T0000Z-210814T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Durham NC-Wake NC-
405 PM EDT Sat Aug 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT THIS 
EVENING FOR SOUTHEASTERN DURHAM AND WESTERN WAKE COUNTIES...

At 405 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Up to 2 inches of rain have fallen. 
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...
  Raleigh, Durham, Cary, Wake Forest, RDU International, Apex, Holly 
  Springs, Morrisville, William B Umstead State Park, Research 
  Triangle, Carpenter, Bethesda, Falls Lake, New Hill, Jordan Lake, 
  Purnell and Shearon Harris Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3587 7891 3604 7881 3607 7876 3607 7868
      3599 7848 3584 7867 3568 7879 3565 7879
      3561 7882 3561 7900 3584 7891

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

10
766 
WGUS72 KRAH 142102
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
502 PM EDT Sat Aug 14 2021

NCC063-142112-
/O.CAN.KRAH.FF.W.0018.000000T0000Z-210814T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Durham NC-
502 PM EDT Sat Aug 14 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN DURHAM COUNTY...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 3576 7873 3568 7879 3565 7879 3561 7882
      3561 7899 3561 7900 3563 7899 3564 7899
      3566 7898 3568 7897 3569 7897 3572 7895
      3573 7895 3577 7893

$$

NCC183-142230-
/O.CON.KRAH.FF.W.0018.000000T0000Z-210814T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wake NC-
502 PM EDT Sat Aug 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT THIS 
EVENING FOR SOUTHWESTERN WAKE COUNTY...

At 502 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Up to 2 inches of rain have fallen. 
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...
  Raleigh, Cary, Apex, Holly Springs, New Hill, Shearon Harris 
  Reservoir and Jordan Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3576 7873 3568 7879 3565 7879 3561 7882
      3561 7899 3561 7900 3563 7899 3564 7899
      3566 7898 3568 7897 3569 7897 3572 7895
      3573 7895 3577 7893

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

10
756 
WGUS72 KRAH 142207
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
607 PM EDT Sat Aug 14 2021

NCC183-142217-
/O.CAN.KRAH.FF.W.0018.000000T0000Z-210814T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wake NC-
607 PM EDT Sat Aug 14 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN WAKE COUNTY...

The heavy rain has ended and flooding is no longer expected to pose 
a threat. However, there may be lingering ponding of water on area 
roadways, so please continue to heed remaining road closures.

LAT...LON 3576 7873 3568 7879 3565 7879 3561 7882
      3561 7899 3561 7900 3563 7899 3564 7899
      3566 7898 3568 7897 3569 7897 3572 7895
      3573 7895 3577 7893

$$

10

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 8:56 PM EDTSpecial Weather StatementRAHVance64 min
Aug 13, 9:36 PM EDTSpecial Weather StatementRAHStanly24 min
Aug 13, 10:11 PM EDTSpecial Weather StatementRAHStanly34 min
Aug 13, 10:45 PM EDTSpecial Weather StatementRAHMontgomery45 min
Aug 13, 11:26 PM EDTSpecial Weather StatementRAHMontgomery, Moore64 min
Aug 14, 12:03 AM EDTSpecial Weather StatementRAHGranville42 min
Aug 14, 12:37 AM EDTSevere Thunderstorm WarningRAHDavidson, Montgomery, Stanly68 min
Aug 14, 4:01 AM EDTHeat AdvisoryRAHChatham, Cumberland, Durham, Edgecombe, Franklin, Granville and 14 more14 hr
Aug 14, 1:46 PM EDTSpecial Weather StatementRAHMoore44 min
Aug 14, 1:47 PM EDTSpecial Weather StatementRAHWake43 min
Aug 14, 2:09 PM EDTSevere Thunderstorm WarningRAHAnson, Stanly51 min
Aug 14, 2:15 PM EDTSevere Thunderstorm WarningRAHFranklin, Johnston, Nash, Wake45 min
Aug 14, 2:33 PM EDTFlash Flood Warning Considerable damage threatRAHFranklin, Wake2 hr
Aug 14, 2:50 PM EDTSevere Thunderstorm WarningRAHWake40 min
Aug 14, 2:55 PM EDTSpecial Weather StatementRAHStanly65 min
Aug 14, 3:01 PM EDTSevere Thunderstorm WarningRAHDurham, Granville, Wake44 min
Aug 14, 3:27 PM EDTSevere Thunderstorm WarningRAHChatham, Harnett, Wake37 min
Aug 14, 3:39 PM EDTSevere Thunderstorm WarningRAHChatham, Durham, Wake51 min
Aug 14, 3:45 PM EDTSpecial Weather StatementRAHDurham60 min
Aug 14, 3:53 PM EDTSevere Thunderstorm WarningRAHDurham, Granville, Wake29 min
Aug 14, 4:08 PM EDTAreal Flood AdvisoryRAHAnson, Richmond70 min
Aug 14, 4:08 PM EDTSpecial Weather StatementRAHAnson, Richmond52 min
Aug 14, 4:38 PM EDTSpecial Weather StatementRAHForsyth67 min
Aug 14, 4:44 PM EDTSpecial Weather StatementRAHWake61 min
Aug 14, 4:50 PM EDTSevere Thunderstorm WarningRAHForsyth40 min
Aug 14, 5:19 PM EDTSevere Thunderstorm WarningRAHAlamance19 min
Aug 14, 5:24 PM EDTAreal Flood AdvisoryRAHForsyth2 hr
Aug 14, 6:25 PM EDTSpecial Weather StatementRAHGuilford35 min
Aug 14, 6:32 PM EDTAreal Flood AdvisoryRAHGuilford118 min
Aug 14, 6:48 PM EDTSpecial Weather StatementRAHGuilford57 min
Aug 14, 7:23 PM EDTFlash Flood Warning Considerable damage threatRAHGuilford2 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.