Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 90

February 16, 200316 counties in North Carolina; 46 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Feb 16, 2003, 2:43 PM EST for 16 counties in North Carolina; 46 counties in Virginia. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Feb 16, 2003, 2:43 PM EST (19:43 UTC)
Expired: Feb 16, 2003, 6:45 PM EST
In force: 4 hr
Issued by: the Storm Prediction Center

All 62 counties

Alamance County, NC, Caswell County, NC, Chatham County, NC, Durham County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Lee County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Rockingham County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Amelia County, VA, Appomattox County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Petersburg, VA, City of Richmond, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Nottoway County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Sussex County, VA, Westmoreland County, VA

The radar

The Norfolk radar (KAKQ), 95 km from the middle of the area, began a volume at 19:45 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

Roanoke, VA (KRNK), launched 12:00Z, 7.7 hours before the alert went out and 133 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: 543 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 326 m²/s²
0-3 km storm-relative helicity: 1067 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.

753 
ACUS11 KWNS 161944
SWOMCD
SPC MCD 161943 
VAZ000-NCZ000-162345-

MESOSCALE DISCUSSION 0090
NWS STORM PREDICTION CENTER NORMAN OK
0143 PM CST SUN FEB 16 2003

AREAS AFFECTED...N CENTRAL NC...CENTRAL AND ERN VA

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 161943Z - 162345Z

A MIXTURE OF SNOW...SLEET...AND FREEZING RAIN WILL CONTINUE
THROUGH THE AFTERNOON WITH HRLY LIQUID WATER EQUIVALENTS OF
0.05-0.15 INCHES.



LATEST SURFACE ANALYSIS SHOWS NEARLY STEADY OR FALLING
TEMPERATURES AT THE SURFACE FROM VA INTO CENTRAL NC.  18Z GSO
SOUNDING SHOWED A CONTINUATION OF COLD AIR ADVECTION THROUGH THE
LOWEST 3KM.  THIS IS IN STARK CONTRAST TO THE STRONGLY VEERING
PROFILE THE ETA AND RUC SOUNDINGS SHOWED...SUGGESTING A DEEPER
THAN FORECAST COLD DOME.  FORECAST PRECIPITATION TYPE BY THE ETA
SHOWED SLEET WHERE THERE IS NOW SNOW OVER MUCH OF CENTRAL VA AND
N-CENTRAL NC.  A RELATIVE MIN IN HOURLY PRESSURE FALLS WAS ALSO
NOTED IN N-CENTRAL NC...SUGGESTING LESS WARMING AND A MIX OF
SLEET AND SNOW RATHER THAN SLEET AND FREEZING RAIN THROUGH THE
AFTERNOON.  THE BEST CHANCE OF FREEZING RAIN WILL BE IN A NARROW
BAND FROM SERN VA SWWD INTO E-CENTRAL NC...AS WARM AIR ADVECTION
JUST OFF THE SURFACE LESSENS THE DEPTH OF THE COLD LAYER THIS
AFTERNOON/EVENING.

..JEWELL.. 02/16/2003

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

37527616 37097702 36237778 35837850 35407927 36058047
36947981 37937868 38157680

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 16, 12:12 AM EST	Mesoscale Discussion	SPC	Alamance, Alexander, Alleghany, Ashe, Avery, Burke and 24 more	5 hr
Feb 16, 10:09 AM EST	Mesoscale Discussion	SPC	Alamance, Alexander, Alleghany, Anson, Ashe, Avery and 40 more	7 hr
Feb 16, 11:45 AM EST	Mesoscale Discussion	SPC	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 20 more	6 hr

Nearby

Mesoscale Discussions in Virginia, 2003 Mesoscale Discussions in North Carolina, 2003 Every mesoscale discussion in 2003

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.