Alert archive / West Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 588

April 26, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2011, 1:49 PM EDT for 4 states. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Apr 26, 2011, 1:49 PM EDT (17:49 UTC)
Expired
Apr 26, 2011, 2:45 PM EDT
In force
56 min
Issued by
the Storm Prediction Center
All 75 counties

Martin County, KY, Allegany County, MD, Garrett County, MD, 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 Radford, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, Craig County, VA, Frederick 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, Shenandoah County, VA, Barbour County, WV, Boone County, WV, Braxton County, WV, Cabell County, WV, Calhoun County, WV, Clay County, WV, Doddridge County, WV, Fayette County, WV, Gilmer County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Harrison County, WV, Jackson County, WV, Kanawha County, WV, Lewis County, WV, Lincoln County, WV, Logan County, WV, Marion County, WV, McDowell County, WV, Mercer County, WV, Mineral County, WV, Mingo County, WV, Monongalia County, WV, Monroe County, WV, Nicholas County, WV, Pendleton County, WV, Pleasants County, WV, Pocahontas County, WV, Preston County, WV, Putnam County, WV, Raleigh County, WV, Randolph County, WV, Ritchie County, WV, Roane County, WV, Summers County, WV, Taylor County, WV, Tucker County, WV, Tyler County, WV, Upshur County, WV, Wayne County, WV, Webster County, WV, Wetzel County, WV, Wirt County, WV, Wyoming County, WV

The radar

The Charleston,WV radar (KRLX), 104 km from the middle of the area, began a volume at 17:52 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 watches that followed

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

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 5.8 hours before the alert went out and 150 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 12:00Z on 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 106 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, Roanoke, VA at 12:00Z on 2011-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 square meters per square second.193958Sfc1 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
106 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
720 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

718 
ACUS11 KWNS 261750
SWOMCD
SPC MCD 261749
VAZ000-WVZ000-MDZ000-PAZ000-OHZ000-KYZ000-261845-

MESOSCALE DISCUSSION 0588
NWS STORM PREDICTION CENTER NORMAN OK
1249 PM CDT TUE APR 26 2011

AREAS AFFECTED...WV...WRN VA

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY

VALID 261749Z - 261845Z

TSTM COVERAGE HAS RECENTLY INCREASED ACROSS WRN WV AND MAY EVOLVE
SIMILARLY TO SCENARIO DESCRIBED IN MCD 0586 WITH UPSCALE GROWTH INTO
CLUSTERS PRODUCING DAMAGING WINDS AND ISOLATED SEVERE HAIL. THE
PROBABILITY OF A SEVERE TSTM WATCH ISSUANCE BY 19Z IS 80 PERCENT.

SHOWER/TSTM ACTIVITY HAS INCREASED ALONG A CONFLUENCE AXIS
STRETCHING FROM SWRN PA INTO ERN KY. TEMPERATURES HAVE NOW WARMED
INTO THE UPPER 70S TO MIDDLE 80S DOWNSTREAM OF THIS AXIS ACROSS WV
INTO WRN VA. ALTHOUGH RECENT HRRR RUNS APPEAR TOO SLOW WITH ONGOING
DEVELOPMENT...THE DEPICTION OF UPSCALE GROWTH INTO ONE OR MORE
CLUSTERS APPEARS PROBABLE AS MLCAPE INCREASES TO BETWEEN 1000 TO
2000 J/KG AND ON THE TRAILING PERIPHERY OF FORCED ASCENT ASSOCIATED
WITH THE UPPER GREAT LAKES SHORT WAVE TROUGH. GIVEN EFFECTIVE SHEAR
OF 35-45 KT...ORGANIZED UPDRAFTS WILL BE CAPABLE OF PRODUCING
DAMAGING WINDS AND ISOLATED SEVERE HAIL.

..GRAMS.. 04/26/2011

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

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

LAT...LON   38138274 39718085 39878008 39627847 39147822 38347858
            37507955 37197995 37048078 37188190 37538248 38138274

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 8:34 PM EDTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 9 more116 min
Apr 26, 12:05 AM EDTMesoscale DiscussionSPCBallard, Butler, Caldwell, Calloway, Carlisle, Christian and 19 more115 min
Apr 26, 12:42 AM EDTSevere Thunderstorm WatchSPCAllen, Barren, Breckinridge, Butler, Caldwell, Calloway and 19 more7 hr
Apr 26, 3:04 AM EDTMesoscale DiscussionSPCAllen, Barren, Breckinridge, Edmonson, Grayson, Hardin and 5 more56 min
Apr 26, 3:41 PM EDTMesoscale DiscussionSPCBallard, Calloway, Carlisle, Fulton, Graves, Hickman and 2 more94 min
Apr 26, 4:02 PM EDTTornado Watch PDSSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more7 hr
Apr 26, 5:38 PM EDTMesoscale DiscussionSPCBreckinridge, Bullitt, Hancock, Henderson, Jefferson, Meade and 2 more37 min
Apr 26, 5:50 PM EDTTornado WatchSPCAllen, Anderson, Barren, Breckinridge, Bullitt, Butler and 25 more5 hr
Apr 26, 7:17 PM EDTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 14 more118 min
Apr 26, 1:18 PM EDTMesoscale DiscussionSPCAllegany, Garrett, Washington57 min
Apr 26, 1:49 PM EDTSevere Thunderstorm WatchSPCGarrett7 hr
Apr 26, 2:09 PM EDTSevere Thunderstorm WatchSPCAllegany, Washington7 hr
Apr 26, 4:34 PM EDTMesoscale DiscussionSPCAllegany, Garrett, Washington56 min
Apr 26, 7:44 PM EDTMesoscale DiscussionSPCAllegany, Garrett, Washington61 min
Apr 26, 2:16 PM EDTMesoscale DiscussionSPCBrunswick, Charles City, Dinwiddie, Gloucester, Greensville, Henrico and 26 more59 min

Nearby

Mesoscale Discussions in West Virginia, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in Maryland, 2011Every mesoscale discussion in 2011

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.