Alert archive / North Carolina / Mesoscale Discussions in 2008

Mesoscale Discussion 2221

September 5, 200819 counties in North Carolina; 6 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2008, 4:00 PM EDT for 19 counties in North Carolina; 6 counties in South Carolina. It was in force for 30 min.

The area

The outline as issued.

The facts

Issued
Sep 5, 2008, 4:00 PM EDT (20:00 UTC)
Expired
Sep 5, 2008, 4:30 PM EDT
In force
30 min
Issued by
the Storm Prediction Center
All 25 counties

Beaufort County, NC, Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Dare County, NC, Duplin County, NC, Greene County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Pitt County, NC, Sampson County, NC, Wayne County, NC, Berkeley County, SC, Charleston County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 28 km from the middle of the area, began a volume at 20:03 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Newport, NC (KMHX), launched 12:00Z, 8.0 hours before the alert went out and 154 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 2008-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 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 2008-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 227 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
5 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
651 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
227 m²/s²
0-3 km storm-relative helicity
276 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.

000 
ACUS11 KWNS 052001
SWOMCD
SPC MCD 052000 
NCZ000-SCZ000-052030-

MESOSCALE DISCUSSION 2221
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT FRI SEP 05 2008

AREAS AFFECTED...ERN NC/PART OF ERN SC

CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON 

VALID 052000Z - 052030Z

ENVIRONMENTAL CONDITIONS ARE BECOMING MORE CONDUCIVE FOR AN
INCREASING TORNADO THREAT AS HANNA APPROACHES THE CAROLINAS. A
TORNADO WATCH ISSUANCE WILL BE COORDINATED BETWEEN THE SPC AND THE
AFFECTED LOCAL NATIONAL WEATHER SERVICE OFFICES DURING THE NEXT
HOUR.

18Z SOUNDINGS ALONG THE SC/NC COAST INDICATED STRENGTHENING ELY
WINDS IN THE LOWER-MID LEVELS DURING THE LAST 6 HOURS....WITH
OBJECTIVE ANALYSES SHOWING AN EFFECTIVE SRH VALUES OF 100-200 M2/S2
FROM THE GA COAST NEWD ALONG THE COASTAL AREAS OF SC/NC.  SURFACE
HEATING COMBINED WITH THE INFLUX OF TROPICAL MOISTURE NOW INTO THE
COASTAL AREAS OF SC/NC WITH SURFACE DEWPOINTS IN THE MIDDLE 70S IS
RESULTING IN GREATER INSTABILITY.

..PETERS.. 09/05/2008

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MHX...RAH...ILM...CHS...

31938037 32698041 33847977 34917871 35627761 35837645
35467510 34697538 34017665 33337781 32307923

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 11:15 AM EDTMesoscale DiscussionSPCBeaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 12 more60 min
Sep 5, 4:39 PM EDTTornado WatchSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 35 more12 hr

Nearby

Mesoscale Discussions in North Carolina, 2008Mesoscale Discussions in South Carolina, 2008Every mesoscale discussion in 2008

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.