Alert archive / North Carolina / Flash Flood Warnings in 2013

Flash Flood Warning 41, NWS Raleigh, NC

July 21, 2013Guilford County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jul 21, 2013, 3:27 PM EDT for Guilford 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 counties it named.

The facts

Issued
Jul 21, 2013, 3:27 PM EDT (19:27 UTC)
Expired
Jul 21, 2013, 5:30 PM EDT
In force
2 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

County Guilford County, NC

The radar

The Roanoke radar (KFCX), 114 km from the middle of the area, began a volume at 19:28 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, 7.5 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 2013-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 345 joules per kilogram.LCLLFCEL10008507005003002001001 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, Greensboro/Hi Pt, NC at 12:00Z on 2013-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
345 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
676 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 2:40 PM EDTSpecial Weather StatementRAHGuilford50 min
Jul 21, 3:12 PM EDTAreal Flood AdvisoryRAHGuilford108 min
Jul 21, 3:34 PM EDTSpecial Weather StatementRAHGuilford41 min
Jul 21, 4:36 PM EDTSpecial Weather StatementRAHPerson39 min
Jul 21, 4:41 PM EDTSpecial Weather StatementRAHAlamance49 min
Jul 21, 4:50 PM EDTSevere Thunderstorm WarningRAHPerson55 min
Jul 21, 6:33 PM EDTAreal Flood AdvisoryRAHGuilford3 hr
Jul 21, 7:03 PM EDTSpecial Weather StatementRAHStanly42 min
Jul 21, 7:37 PM EDTAreal Flood AdvisoryRAHStanly3 hr

Nearby

Flash Flood Warnings in North Carolina, 2013Every flash flood warning in 2013

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.