Alert archive / South Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 18

January 10, 201120 counties in North Carolina; 30 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jan 10, 2011, 11:27 AM EST for 20 counties in North Carolina; 30 counties in South Carolina. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jan 10, 2011, 11:27 AM EST (16:27 UTC)
Expired: Jan 10, 2011, 5:30 PM EST
In force: 6 hr
Issued by: the Storm Prediction Center

All 50 counties

Anson County, NC, Bladen County, NC, Brunswick County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Duplin County, NC, Harnett County, NC, Hoke County, NC, Jones County, NC, Lenoir County, NC, Moore County, NC, Onslow County, NC, Pender County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Union County, NC, Wayne County, NC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Greenwood County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 78 km from the middle of the area, began a volume at 16:28 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

Charleston AFB, SC (KCHS), launched 12:00Z, 4.5 hours before the alert went out and 158 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1119 m above ground
0-6 km bulk shear: 80 kt
0-1 km storm-relative helicity: 515 m²/s²
0-3 km storm-relative helicity: 1077 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.

038 
ACUS11 KWNS 101627
SWOMCD
SPC MCD 101627 
NCZ000-SCZ000-102230-

MESOSCALE DISCUSSION 0018
NWS STORM PREDICTION CENTER NORMAN OK
1027 AM CST MON JAN 10 2011

AREAS AFFECTED...MUCH OF SC AND ADJACENT SRN NC

CONCERNING...FREEZING RAIN 

VALID 101627Z - 102230Z

FREEZING RAIN RATES IN EXCESS OF A FEW HUNDREDTHS OF AN INCH PER
HOUR -- GREATER THAN .05" IN THREE HOURS -- ARE EXPECTED TO EXPAND
NWD WITH TIME ACROSS THE REMAINDER OF NRN SC AND INTO NC.

LATEST SURFACE ANALYSIS SHOWS SURFACE TEMPERATURES BELOW FREEZING
ACROSS THE CAROLINAS WITH THE EXCEPTION OF COASTAL AREAS...WITH THE
SURFACE WET-BULB ZERO LINE ROUGHLY PARALLELING THE COAST.  WHILE
PRECIPITATION HAS SWITCHED TO RAIN IN FAR SRN SC...A MIX OF FREEZING
RAIN AND SLEET CONTINUES ACROSS ROUGHLY THE CENTRAL THIRD OF
SC...WITH AREAS FARTHER N INTO NRN SC AND NC REMAINING ALL SNOW
ATTM.

WITH TIME...LOW-LEVEL WARM ADVECTION WILL CONTINUE ACROSS THIS
REGION...WITH H8 TEMPERATURES EXPECTED TO RISE A COUPLE OF DEGREES
OVER THE NEXT 3-6 HOURS.  AS THIS OCCURS...A GRADUAL CHANGEOVER FROM
SNOW TO SLEET -- AND THEN TO FREEZING RAIN -- WILL
CONTINUE...SPREADING NWD INTO NC BY EARLY AFTERNOON.

WITH LOW-LEVEL WARM ADVECTION AHEAD OF THE ADVANCING MID-LEVEL
SYSTEM PROVIDING AMPLE QG FORCING FOR CONTINUED STEADY
PRECIPITATION...FREEZING RAIN RATES OF AT LEAST A FEW HUNDREDTHS OF
AN INCH PER HOUR CAN BE EXPECTED ACROSS MOST OF THE DISCUSSION AREA.

..GOSS.. 01/10/2011

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

ATTN...WFO...MHX...RAH...ILM...CHS...CAE...GSP...

LAT...LON   33347943 32928011 32808120 34138241 34668171 35427948
            35487783 35177687 34737716 34437763 34047804 33847893
            33347943

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 9, 11:56 PM EST	Mesoscale Discussion	SPC	Cherokee, Clay, Graham, Jackson, Macon, Transylvania	5 hr
Jan 10, 3:06 AM EST	Mesoscale Discussion	SPC	Aiken, Allendale, Bamberg, Barnwell, Berkeley, Calhoun and 6 more	6 hr

Nearby

Mesoscale Discussions in South Carolina, 2011 Mesoscale Discussions in North Carolina, 2011 Every mesoscale discussion in 2011

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.