Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 355

March 30, 20036 states

The Storm Prediction Center issued this mesoscale discussion at Mar 30, 2003, 12:07 AM EST for 6 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Mar 30, 2003, 12:07 AM EST (05:07 UTC)
Expired
Mar 30, 2003, 4:00 AM EST
In force
4 hr
Issued by
the Storm Prediction Center
All 91 counties

Fannin County, GA, Habersham County, GA, Rabun County, GA, Towns County, GA, Union County, GA, White County, GA, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rutherford County, NC, Surry County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yancey County, NC, Oconee County, SC, Pickens County, SC, Blount County, TN, Carter County, TN, Cocke County, TN, Greene County, TN, Hamblen County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Monroe County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN, Alleghany County, VA, Bath County, VA, Bland County, VA, Botetourt County, VA, Buchanan County, VA, Carroll County, VA, City of Bristol, VA, City of Covington, VA, City of Galax, VA, City of Lexington, VA, City of Norton, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Dickenson County, VA, Floyd County, VA, Giles County, VA, Grayson County, VA, Highland County, VA, Montgomery County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA, Braxton County, WV, Clay County, WV, Fayette County, WV, Greenbrier County, WV, McDowell County, WV, Mercer County, WV, Monroe County, WV, Nicholas County, WV, Pocahontas County, WV, Raleigh County, WV, Randolph County, WV, Summers County, WV, Webster County, WV, Wyoming County, WV

The radar

The Roanoke radar (KFCX), 124 km from the middle of the area, began a volume at 05:11 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 5.1 hours before the alert went out and 173 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, Greensboro/Hi Pt, NC at 00:00Z on 2003-03-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 183 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, Greensboro/Hi Pt, NC at 00:00Z on 2003-03-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.19395878Sfc1 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
183 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
1309 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
ACUS11 KWNS 300508
SWOMCD
SPC MCD 300507 
VAZ000-WVZ000-NCZ000-TNZ000-SCZ000-KYZ000-GAZ000-300900-

MESOSCALE DISCUSSION 0355
NWS STORM PREDICTION CENTER NORMAN OK
1107 PM CST SAT MAR 29 2003

AREAS AFFECTED...ERN WV/WRN VA SWD INTO ERN TN/WRN NC

CONCERNING...HEAVY SNOW 

VALID 300507Z - 300900Z

HEAVY SNOW WITH RATES OF 1 TO 2 INCHES/HOUR ARE EXPECTED TO
DEVELOP OVER THE HIGHER ELEVATIONS OF THE APPALACHIANS FROM FAR
WRN NC NWD INTO ERN WV AND WRN VA BY 08 OR 09Z.



LATEST WATER VAPOR IMAGERY AND 00Z UPPER-AIR ANALYSIS SHOW
SHORTWAVE TROUGH AND ASSOCIATED UPPER-LEVEL JET STREAK
TRANSLATING NEWD ACROSS THE CNTRL GULF COAST. REGIONAL RADAR DATA
SHOWS PRECIPITATION SHIELD AHEAD OF THE SHORTWAVE TROUGH
CONTINUING TO EXPAND NEWD ACROSS AL/WRN GA INTO WRN NC. CURRENT
SURFACE OBSERVATIONS AHEAD OF THIS PRECIPITATION INDICATE
TEMPERATURES IN THE UPPER 30S TO LOWER 40S ACROSS THE SMOKEY
MOUNTAINS WITH GENERALLY MID 30S OVER THE HIGHER ELEVATIONS OF
ERN WV/WRN VA.



00Z ETA AND 03Z RUC GUIDANCE BOTH SUGGEST THAT FORCING FOR LARGE
SCALE ASCENT WILL SIGNIFICANTLY INCREASE ACROSS THE AREA BETWEEN
06 AND 09Z AS AS DIVERGENT LEFT EXIT REGION OF UPPER-LEVEL JET
STREAK MOVES OVER THE AREA. MOREOVER...RESPONSE TO INTENSIFYING
700-500 MB BAROCLINIC ZONE ORIENTED PARALLEL TO THE APPALACHIANS 
SHOULD FURTHER ENHANCE AND DEEPEN VERTICAL CIRCULATION BENEATH
UPPER JET EXIT REGION. LOW-LEVEL COLD ADVECTION AND EVAPORATIVE
COOLING WITH THE ONSET OF PRECIPITATION SHOULD CREATE SURFACE
CONDITIONS SUPPORTIVE OF SNOW AT THIS TIME. RUC POINT FORECAST
SOUNDINGS INDICATE THE POTENTIAL FOR HEAVY SNOW AS THIS
DEEP-LAYER FORCING FOR UPWARD VERTICAL MOTION WILL BE COINCIDENT
WITH THAT PORTION OF SATURATED THERMODYNAMIC PROFILE FAVORABLE
FOR DENDRITIC GROWTH.



THE HEAVIER SNOWFALL RATES SHOULD PERSIST THROUGH THE 12Z TO 14Z
TIME FRAME BEFORE THE STRONGER DYNAMIC FORCING SHIFTS E ACROSS
LOWER ELEVATIONS.

..MEAD.. 03/30/2003

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

ATTN...WFO...LWX...RNK...RLX...GSP...MRX...JKL...FFC...

38038168 38888076 38907993 38737937 38097919 37377976
36688046 35658132 35168190 34758284 34558365 34848439
35338453 36638308

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 30, 10:10 AM ESTMesoscale DiscussionSPCAlbemarle, Amherst, Augusta, Bath, Clarke, Frederick and 19 more3 hr

Nearby

Mesoscale Discussions in Virginia, 2003Mesoscale Discussions in North Carolina, 2003Mesoscale Discussions in West Virginia, 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.