Alert archive / North Carolina / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS Raleigh, NC

July 18, 2017Forsyth County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jul 18, 2017, 4:48 PM EDT for Forsyth County, North Carolina. It was in force for 2 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: Jul 18, 2017, 4:48 PM EDT (20:48 UTC)
Expired: Jul 18, 2017, 7:15 PM EDT
In force: 2 hr
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Flood severity: None

County Forsyth County, NC

The radar

The Roanoke radar (KFCX), 106 km from the middle of the area, began a volume at 20:47 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, 8.8 hours before the alert went out and 32 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: 951 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 879 m above ground
0-6 km bulk shear: 2 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 19 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

384 
WGUS52 KRAH 182048
FFWRAH
NCC067-182315-
/O.NEW.KRAH.FF.W.0013.170718T2048Z-170718T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Raleigh NC
448 PM EDT TUE JUL 18 2017

The National Weather Service in Raleigh has issued a

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

* Until 715 PM EDT

* At 447 PM EDT, Doppler radar indicated training thunderstorms that 
  were continuously redeveloping over Winston-Salem. Up to one inch 
  of rain has already fallen. Additional 1 to 2 inches may fall 
  creating flash flooding.

* Some locations that will experience flooding include...
  Winston-Salem and Pfafftown. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

Excessive runoff from the heavy rain will cause flash flooding of
creeks and streams, roads, low lying and poor drainage areas. Do not
drive your vehicle into areas where water covers the road. Many roads
and intersections in the area will quickly flood. When encountering
flooded roads, turn around, don't drown.

&&

LAT...LON 3615 8033 3615 8018 3603 8017 3603 8021
      3600 8022 3601 8036

$$

Badgett

1 follow-up statement

796 
WGUS72 KRAH 182139
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
539 PM EDT TUE JUL 18 2017

NCC067-182148-
/O.CAN.KRAH.FF.W.0013.000000T0000Z-170718T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Forsyth NC-
539 PM EDT TUE JUL 18 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL FORSYTH COUNTY IS
CANCELLED...

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

Call 8 0 0 4 4 4 7 9 2 8 to report flooding or damage from these 
storm to the National Weather Service.

LAT...LON 3615 8033 3615 8018 3603 8017 3603 8021
      3600 8022 3601 8036

$$

Badgett

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 5:48 AM EDT	Special Weather Statement	RAH	Bladen	57 min
Jul 18, 3:44 PM EDT	Special Weather Statement	RAH	Orange	61 min
Jul 18, 4:07 PM EDT	Special Weather Statement	RAH	Forsyth	53 min
Jul 18, 4:23 PM EDT	Areal Flood Advisory	RAH	Forsyth	3 hr
Jul 18, 4:26 PM EDT	Severe Thunderstorm Warning	RAH	Davidson, Forsyth	64 min
Jul 18, 4:36 PM EDT	Special Weather Statement	RAH	Randolph	54 min
Jul 18, 4:41 PM EDT	Severe Thunderstorm Warning	RAH	Randolph	9 min
Jul 18, 4:46 PM EDT	Special Weather Statement	RAH	Alamance	44 min
Jul 18, 4:57 PM EDT	Special Weather Statement	RAH	Durham	63 min
Jul 18, 5:08 PM EDT	Special Weather Statement	RAH	Chatham, Lee, Moore	67 min
Jul 18, 5:16 PM EDT	Severe Thunderstorm Warning	RAH	Alamance, Guilford, Randolph	44 min
Jul 18, 5:29 PM EDT	Special Weather Statement	RAH	Davidson	61 min
Jul 18, 5:54 PM EDT	Areal Flood Advisory	RAH	Guilford	66 min
Jul 18, 6:04 PM EDT	Special Weather Statement	RAH	Chatham	41 min
Jul 18, 6:10 PM EDT	Special Weather Statement	RAH	Richmond	65 min
Jul 18, 6:13 PM EDT	Special Weather Statement	RAH	Lee	62 min
Jul 18, 6:28 PM EDT	Special Weather Statement	RAH	Granville, Person	62 min
Jul 18, 6:31 PM EDT	Special Weather Statement	RAH	Montgomery, Stanly	59 min
Jul 18, 6:33 PM EDT	Special Weather Statement	RAH	Anson	57 min
Jul 18, 6:41 PM EDT	Severe Thunderstorm Warning	RAH	Anson, Richmond	64 min
Jul 18, 6:48 PM EDT	Severe Thunderstorm Warning	RAH	Davidson, Montgomery, Randolph, Stanly	72 min
Jul 18, 7:09 PM EDT	Special Weather Statement	RAH	Person	51 min
Jul 18, 7:10 PM EDT	Areal Flood Advisory	RAH	Anson, Richmond	3 hr
Jul 18, 7:23 PM EDT	Flash Flood Warning	RAH	Anson, Richmond	3 hr
Jul 18, 7:38 PM EDT	Flash Flood Warning	RAH	Montgomery, Stanly	3 hr
Jul 18, 7:42 PM EDT	Special Weather Statement	RAH	Anson, Richmond	63 min

Nearby

Flash Flood Warnings in North Carolina, 2017 Every flash flood warning in 2017

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.