Alert archive / North Carolina / Mesoscale Discussions in 2017

Mesoscale Discussion 1427

July 28, 20176 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Jul 28, 2017, 4:32 PM EDT for 6 counties in North Carolina. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Jul 28, 2017, 4:32 PM EDT (20:32 UTC)
Expired
Jul 28, 2017, 6:00 PM EDT
In force
88 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Bertie County, NC, Chowan County, NC, Halifax County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC

The radar

The Norfolk radar (KAKQ), 89 km from the middle of the area, began a volume at 20:31 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

Newport, NC (KMHX), launched 12:00Z, 8.5 hours before the alert went out and 157 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, Newport, NC at 12:00Z on 2017-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 546 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, Newport, NC at 12:00Z on 2017-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
546 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
857 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 28, 3:00 PM EDTMesoscale DiscussionSPCBertie, Camden, Chowan, Currituck, Durham, Edgecombe and 18 more90 min

Nearby

Mesoscale Discussions in North Carolina, 2017Every mesoscale discussion 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.