Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 1353

July 1, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 8:32 PM EDT for 5 states. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Jul 1, 2012, 8:32 PM EDT (00:32 UTC)
Expired: Jul 1, 2012, 10:00 PM EDT
In force: 88 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 70 counties

Floyd County, KY, Knott County, KY, Leslie County, KY, Letcher County, KY, Magoffin County, KY, Perry County, KY, Pike County, KY, Allegany County, MD, Garrett County, MD, Bedford County, PA, Fayette County, PA, Greene County, PA, Somerset County, PA, Westmoreland County, PA, Alleghany County, VA, Augusta County, VA, Bath County, VA, Bland County, VA, Botetourt County, VA, Buchanan County, VA, City of Buena Vista, VA, City of Covington, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Norton, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, Craig County, VA, Dickenson County, VA, Floyd County, VA, Giles County, VA, Highland County, VA, Montgomery County, VA, Page County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Russell County, VA, Shenandoah County, VA, Smyth County, VA, Tazewell County, VA, Wise County, VA, Wythe County, VA, Barbour County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Harrison County, WV, Marion County, WV, McDowell County, WV, Mercer County, WV, Mineral County, WV, Monongalia County, WV, Monroe County, WV, Pendleton 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 452Jul 1, 9:05 PM EDT

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 0.5 hours before the alert went out and 183 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: 102 J/kg
Mixed-layer CIN: -174 J/kg
Mixed-layer LCL: 2439 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 65 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.

199 
ACUS11 KWNS 020032
SWOMCD
SPC MCD 020032 
PAZ000-VAZ000-WVZ000-MDZ000-KYZ000-020200-

MESOSCALE DISCUSSION 1353
NWS STORM PREDICTION CENTER NORMAN OK
0732 PM CDT SUN JUL 01 2012

AREAS AFFECTED...SWRN PA...WRN VA...ERN/SRN WV...ERN KY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 020032Z - 020200Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A SVR TSTM WATCH MAY BE NEEDED FOR AREAS TO THE E OF WW/S
446/447/448 DURING THE NEXT HOUR OR TWO.

DISCUSSION...CONVECTION AT THE LEADING EDGE OF AN INTENSIFYING COLD
POOL ACROSS CNTRL OHIO CONTINUES TO MODESTLY ACCELERATE
ESEWD/SEWD...WITH STORM MOTIONS NOW REACHING 40-45 KT. AND WITH
25-35 KT OF EFFECTIVE BULK SHEAR...FORWARD PROPAGATION INTO A ZONE
OF STRONG INSTABILITY FEATURING MLCAPE VALUES OF 2000-3500 J/KG MAY
TAKE THE SVR THREAT EAST OF ONGOING OH/WV/KY/IND WATCHES IN THE NEXT
COUPLE OF HOURS. TRENDS WILL CONTINUE TO BE MONITORED DURING THE
NEXT COUPLE OF HOURS FOR DOWNSTREAM WW ISSUANCE...AS LACK OF RECENT
ANTECEDENT OVERTURNING MAY SUPPORT A MORE WIDESPREAD SVR THREAT INTO
THE EVENING/OVERNIGHT.

..COHEN/HART.. 07/02/2012

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

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

LAT...LON   40097834 38357845 36908013 36708296 37098349 37728315
            37648216 37658157 38008096 38608053 39608033 40348020
            40757932 40097834

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 1, 8:21 PM EDT	Mesoscale Discussion	SPC	Boyd, Carter, Greenup, Lawrence	54 min
Jul 1, 9:02 PM EDT	Mesoscale Discussion	SPC	Anderson, Boone, Bourbon, Boyle, Bracken, Breckinridge and 33 more	58 min
Jul 1, 9:06 PM EDT	Severe Thunderstorm Watch	SPC	Breathitt, Estill, Floyd, Harlan, Knott, Lee and 5 more	5 hr
Jul 1, 10:26 PM EDT	Mesoscale Discussion	SPC	Adair, Anderson, Bath, Bourbon, Boyd, Boyle and 46 more	94 min
Jul 2, 6:16 PM EDT	Mesoscale Discussion	SPC	Adair, Allen, Ballard, Barren, Breckinridge, Bullitt and 40 more	2 hr
Jul 2, 12:39 AM EDT	Mesoscale Discussion	SPC	Montgomery	96 min

Nearby

Mesoscale Discussions in Virginia, 2012 Mesoscale Discussions in West Virginia, 2012 Mesoscale Discussions in Kentucky, 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.