Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 27

January 16, 2003Sussex County, Delaware; 5 counties in Maryland; 36 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jan 16, 2003, 9:53 PM EST for Sussex County, Delaware; 5 counties in Maryland; 36 counties in Virginia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jan 16, 2003, 9:53 PM EST (02:53 UTC)
Expired
Jan 17, 2003, 4:00 AM EST
In force
6 hr
Issued by
the Storm Prediction Center
All 42 counties

Sussex County, DE, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Accomack County, VA, Charles City County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Williamsburg, VA, Dinwiddie County, VA, Essex County, VA, Gloucester County, VA, Greensville County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 73 km from the middle of the area, began a volume at 02:54 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.9 hours before the alert went out and 108 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, Wallops Is Stn, VA at 00:00Z on 2003-01-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Wallops Is Stn, VA at 00:00Z on 2003-01-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1505 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
198 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.

242 
ACUS11 KWNS 170254
SWOMCD
SPC MCD 170253 
VAZ000-DEZ000-MDZ000-170900-

MESOSCALE DISCUSSION 0027
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CST THU JAN 16 2003

AREAS AFFECTED...ERN VA...SRN DE...SRN DELMARVA PENNINSULA

CONCERNING...HEAVY SNOW

VALID 170253Z - 170900Z

MDT TO HEAVY SNOW IS EXPECTED TO FORM BETWEEN 04-06Z.  SNOW RATES
NEAR 1 IN/HR WILL BE POSSIBLE THROUGH ABOUT 09Z.  POCKETS OF FZRA
WILL ALSO BE POSSIBLE OVER EXTREME SERN VA.


CURRENT RADAR TRENDS SHOW INCREASING DBZ OVER ERN NC AND SERN VA.
VERY DRY AIR MASS IN PLACE HAS KEPT HOURLY PRECIPITATION RATES
LOW THROUGH THE EVENING...HOWEVER...LATEST SURFACE OBSERVATIONS
UPSTREAM SHOW HOURLY LIQUID RATES EXCEEDING /0.10/ PER HOUR.
ETA AND RUC FORECAST SOUNDINGS SHOW LOW LEVELS BECOMING SATURATED
BETWEEN 04-06Z...WITH VERY STRONG UVVS CONTINUING THROUGH ABOUT
9Z.  PRECIPITATION TYPE IS EXPECTED TO BE PRIMARILY SNOW NORTH OF
NORFOLK VA...WITH THE HEAVIEST ACCUMULATIONS OVER EXTREME
E-CENTRAL VA INTO THE CENTRAL DELMARVA PENINSULA.

..JEWELL.. 01/17/2003

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

36887608 36727689 36657750 36787783 37287767 38287693
38877565 38767486 37837542

Nearby

Mesoscale Discussions in Virginia, 2003Mesoscale Discussions in Maryland, 2003Mesoscale Discussions in Delaware, 2003Every 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.