Alert archive / West Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 2095

October 30, 20126 states

The Storm Prediction Center issued this mesoscale discussion at Oct 30, 2012, 1:02 PM EDT for 6 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Oct 30, 2012, 1:02 PM EDT (17:02 UTC)
Expired: Oct 30, 2012, 6:00 PM EDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 51 counties

Letcher County, KY, Pike County, KY, Garrett County, MD, Haywood County, NC, Madison County, NC, Mitchell County, NC, Swain County, NC, Carter County, TN, Cocke County, TN, Johnson County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN, Bland County, VA, Buchanan County, VA, City of Bristol, VA, City of Norton, VA, Dickenson County, VA, Giles County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA, Barbour County, WV, Boone County, WV, Braxton County, WV, Clay County, WV, Fayette County, WV, Greenbrier County, WV, Kanawha County, WV, Lewis County, WV, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Monroe County, WV, Nicholas County, WV, Pocahontas County, WV, Preston County, WV, Raleigh County, WV, Randolph County, WV, Summers County, WV, Taylor County, WV, Tucker County, WV, Upshur County, WV, Webster County, WV, Wyoming County, WV

The radar

The Charleston,WV radar (KRLX), 138 km from the middle of the area, began a volume at 17:03 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 12:00Z, 5.0 hours before the alert went out and 208 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: 1100 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 46 m²/s²
0-3 km storm-relative helicity: -33 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.

898 
ACUS11 KWNS 301703
SWOMCD
SPC MCD 301702
WVZ000-MDZ000-VAZ000-NCZ000-TNZ000-KYZ000-302200-

MESOSCALE DISCUSSION 2095
NWS STORM PREDICTION CENTER NORMAN OK
1202 PM CDT TUE OCT 30 2012

AREAS AFFECTED...FAR WRN MD...PARTS OF WV...ERN KY...WRN VA...FAR
ERN TN...FAR WRN NC

CONCERNING...HEAVY SNOW

VALID 301702Z - 302200Z

SUMMARY...MODERATE TO LOCALLY HEAVY SNOW WILL CONTINUE THROUGH THE
DAY...THOUGH SNOWFALL RATES ARE EXPECTED TO DECREASE.
HOWEVER...LOCALIZED NEAR-1-IN/HR SNOWFALL RATES WILL REMAIN POSSIBLE
THROUGH THE AFTERNOON AMIDST AREAS OF STRONG/GUSTY WINDS.

DISCUSSION...POST-TROPICAL CYCLONE SANDY WAS CENTERED OVER SWRN PA
AS OF 16Z...WITH A MINIMUM CENTRAL PRESSURE OF 983 MB AS OF 15Z PER
THE LATEST ADVISORY FROM THE HYDROMETEOROLOGICAL PREDICTION CENTER.
UPSLOPE FLOW NEAR AND WEST OF A TERTIARY FRONTAL BOUNDARY THAT
TRAILS SSWWD FROM THE OCCLUDED LOW WILL CONTINUE TO DRIVE UPSLOPE
PRECIPITATION ACROSS THE CNTRL/SRN APPALACHIANS THROUGH THIS
AFTERNOON. CHARLESTON WV VWP DATA INDICATE 20-45 KT OF LOW-LEVEL
FLOW ASSOCIATED WITH AN APPRECIABLE MOUNTAIN-RANGE ORTHOGONAL
COMPONENT. WHILE MODERATE TO LOCALLY HEAVY SNOW WILL OCCUR...WITH
SNOWFALL RATES REACHING NEAR 1 IN/HR...AN OVERALL DOWNWARD TREND IN
SNOWFALL RATES IS ANTICIPATED IN CONCERT WITH THE LOW/S FILLING
PROCESS AND WEAKENING OF THE DEEP-LAYER FLOW FIELDS. SNOWFALL RATES
WILL BE HIGHEST FOR ELEVATIONS AOA 2000 FT...WHERE FORECAST
SOUNDINGS INDICATE THE GREATEST DEPTH OF SUBFREEZING TEMPERATURES
THROUGH THE ATMOSPHERIC COLUMN. THIS IS CONSISTENT WITH THE
CONSENSUS AMONGST HIGH-RESOLUTION WRF GUIDANCE...INCLUDING
EXPERIMENT SPC SSEO GUIDANCE.

FORECAST SOUNDINGS SUGGEST THAT SUSTAINED WIND SPEEDS OF 15-30 MPH
WITH HIGHER GUSTS WILL OCCUR...STRONGEST OVER RIDGE TOPS. THESE
WINDS WILL CAUSE CONSIDERABLE BLOWING AND DRIFTING OF SNOW AND
WHITEOUT CONDITIONS AT TIMES...ESPECIALLY OVER THE HIGHER
ELEVATIONS. HOWEVER...WIND SPEEDS SHOULD GENERALLY DECREASE BY EARLY
THIS EVENING...AS THE PRESSURE GRADIENT GRADUALLY SLACKENS AROUND
WEAKENING POST-TROPICAL CYCLONE SANDY.

..COHEN.. 10/30/2012

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

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

LAT...LON   38387960 37118075 36278170 35488296 35368349 35438388
            35718382 35988309 36318248 36478243 36698257 36728281
            37038308 37738235 39188041 39647950 39497912 38387960

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 30, 4:34 AM EDT	Mesoscale Discussion	SPC	Bath, Boyd, Breathitt, Carter, Elliott, Fleming and 16 more	4 hr

Nearby

Mesoscale Discussions in West Virginia, 2012 Mesoscale Discussions in Virginia, 2012 Mesoscale Discussions in Tennessee, 2012 Every mesoscale discussion in 2012

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.