Alert archive / Virginia / Mesoscale Discussions in 2014

Mesoscale Discussion 166

March 3, 201411 counties in Maryland; 40 counties in Virginia; 22 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 3, 2014, 12:47 AM EST for 11 counties in Maryland; 40 counties in Virginia; 22 counties in West Virginia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Mar 3, 2014, 12:47 AM EST (05:47 UTC)
Expired
Mar 3, 2014, 5:45 AM EST
In force
5 hr
Issued by
the Storm Prediction Center
All 73 counties

Anne Arundel County, MD, Baltimore County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Albemarle County, VA, Alleghany County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Manassas, VA, City of Manassas Park, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Boone County, WV, Braxton County, WV, Clay County, WV, Fayette County, WV, Greenbrier County, WV, Hardy County, WV, Jefferson County, WV, Kanawha County, WV, Lincoln County, WV, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Monroe County, WV, Nicholas County, WV, Pendleton County, WV, Pocahontas County, WV, Raleigh County, WV, Randolph County, WV, Summers County, WV, Webster County, WV, Wyoming County, WV

The radar

The Sterling radar (KLWX), 162 km from the middle of the area, began a volume at 05:47 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 00:00Z, 5.8 hours before the alert went out and 141 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, Roanoke, VA at 00:00Z on 2014-03-03Temperature 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, Roanoke, VA at 00:00Z on 2014-03-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 143 square meters per square second.1939587897117Sfc1 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
755 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
143 m²/s²
0-3 km storm-relative helicity
171 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.

816 
ACUS11 KWNS 030548
SWOMCD
SPC MCD 030547 
MDZ000-PAZ000-DCZ000-VAZ000-WVZ000-KYZ000-031045-

MESOSCALE DISCUSSION 0166
NWS STORM PREDICTION CENTER NORMAN OK
1147 PM CST SUN MAR 02 2014

AREAS AFFECTED...PARTS OF SRN/ERN WV...WRN/NRN VA...DC...CNTRL MD

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 030547Z - 031045Z

SUMMARY...A MIX OF ALL WINTER PRECIP TYPES WILL PERSIST AND
GRADUALLY DEVELOP SWD THIS MORNING. LIQUID-EQUIVALENT PRECIPITATION
RATES THROUGH 12Z WILL BE HIGHEST ACROSS SRN WV INTO CNTRL
VA...REACHING 0.10-0.25 IN/HR. TOWARDS 12Z...A TRANSITION TO
MODERATE SNOW/SLEET SHOULD DEVELOP WITHIN A NARROW CORRIDOR ACROSS
SRN WV TOWARDS THE DC METRO AREA WITH RATES APPROACHING 1 IN/HR.

DISCUSSION...05Z SURFACE ANALYSIS PLACED A COLD FRONT ARCING ACROSS
SWRN VA TO THE SERN VA/NERN NC BORDER...WITH THE WET-BULB FREEZING
LINE LAGGING THE FRONT FROM SRN WV TO CNTRL MD. VWP DATA FROM
LWX/RLX ONLY SAMPLED AROUND 10 KT 0-1 KM NLYS. THESE WILL LIKELY
STRENGTHEN SOMEWHAT DURING THE NEXT SEVERAL HOURS AS RIDGING BUILDS
FROM THE GREAT LAKES TO THE MID-ATLANTIC. THIS SHOULD RESULT IN
INCREASING CAA BELOW THE LOW-LEVEL INVERSION NOTED IN 00Z BNA/IAD
RAOBS AND RECENT AMDAR DATA NEAR BWI. ONGOING RAIN OVER MOST OF VA
INTO DC/CNTRL MD WILL TRANSITION TO WINTER PTYPES AS AN EXTENSIVE
PRECIPITATION SWATH PERSISTS WITHIN THE WARM CONVEYOR DOWNSTREAM OF
A SHORTWAVE TROUGH NEAR THE OZARK PLATEAU.

HEAVIEST PRECIPITATION RATES WILL LIKELY DEVELOP INTO SRN WV AND
CNTRL VA FROM TN/KY AS THE SHORTWAVE TROUGH ACCELERATES E/NEWD.
DOMINANT WINTER PTYPES SHOULD BE FREEZING RAIN INITIALLY BEHIND THE
SURFACE FREEZING LINE...WITH AN INCREASINGLY BROAD CORRIDOR OF MIXED
SLEET/FREEZING RAIN AND LIGHT SNOW. TOWARDS 12Z...TRANSITION TO
MAINLY SNOW/SLEET FROM N/S WILL OCCUR WITH A NARROW BAND OF SNOWFALL
RATES NEAR 1 IN/HR MOST PROBABLE FROM PORTIONS OF SRN WV TOWARDS DC.

..GRAMS.. 03/03/2014

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

ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...JKL...

LAT...LON   37178168 37788239 38318225 38668126 39027942 39597749
            39747668 39647621 39407600 38767623 37967795 37667921
            37468070 37178168

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 3, 6:05 AM ESTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more6 hr
Mar 3, 12:50 AM ESTMesoscale DiscussionSPCLee, Scott, Wise, City of Norton5 hr

Nearby

Mesoscale Discussions in Virginia, 2014Mesoscale Discussions in West Virginia, 2014Mesoscale Discussions in Maryland, 2014Every mesoscale discussion in 2014

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.