Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 1627

July 27, 201233 counties in North Carolina; 5 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2012, 7:50 PM EDT for 33 counties in North Carolina; 5 counties in Virginia. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Jul 27, 2012, 7:50 PM EDT (23:50 UTC)
Expired
Jul 27, 2012, 9:15 PM EDT
In force
85 min
Issued by
the Storm Prediction Center
All 38 counties

Bertie County, NC, Camden County, NC, Chatham County, NC, Chowan County, NC, Cumberland County, NC, Currituck County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Martin County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Richmond County, NC, Sampson County, NC, Scotland County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, City of Chesapeake, VA, City of Norfolk, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA

The radar

The Raleigh/Durham radar (KRAX), 57 km from the middle of the area, began a volume at 23:52 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, 11.8 hours before the alert went out and 144 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 2012-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2927 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 2012-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.193958Sfc1 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
2927 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1165 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 27, 1:08 PM EDTMesoscale DiscussionSPCRockingham, Stokes, Surry67 min
Jul 27, 1:54 PM EDTMesoscale DiscussionSPCAvery, Buncombe, Burke, Caldwell, Cherokee, Clay and 11 more66 min
Jul 27, 1:54 PM EDTSevere Thunderstorm WatchSPCAlamance, Alleghany, Anson, Ashe, Bertie, Camden and 41 more8 hr
Jul 27, 4:52 PM EDTMesoscale DiscussionSPCAlamance, Alleghany, Caswell, Forsyth, Granville, Guilford and 7 more53 min
Jul 26, 9:06 PM EDTMesoscale DiscussionSPCArlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 17 more84 min

Nearby

Mesoscale Discussions in North Carolina, 2012Mesoscale Discussions in Virginia, 2012Every mesoscale discussion in 2012

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.