Alert archive / Ohio / Mesoscale Discussions in 2011

Mesoscale Discussion 761

May 12, 201118 counties in Ohio; 11 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 12, 2011, 3:36 PM EDT for 18 counties in Ohio; 11 counties in West Virginia. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: May 12, 2011, 3:36 PM EDT (19:36 UTC)
Expired: May 12, 2011, 5:00 PM EDT
In force: 84 min
Issued by: the Storm Prediction Center

All 29 counties

Ashland County, OH, Belmont County, OH, Carroll County, OH, Coshocton County, OH, Guernsey County, OH, Harrison County, OH, Holmes County, OH, Medina County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Richland County, OH, Stark County, OH, Summit County, OH, Tuscarawas County, OH, Washington County, OH, Wayne County, OH, Braxton County, WV, Calhoun County, WV, Clay County, WV, Doddridge County, WV, Gilmer County, WV, Lewis County, WV, Pleasants County, WV, Ritchie County, WV, Tyler County, WV, Wirt County, WV, Wood County, WV

The radar

The Pittsburgh radar (KPBZ), 116 km from the middle of the area, began a volume at 19:36 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

Pittsburgh, PA (KPIT), launched 12:00Z, 7.6 hours before the alert went out and 120 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: 1624 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 44 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.

628 
ACUS11 KWNS 121937
SWOMCD
SPC MCD 121936
WVZ000-OHZ000-122100-

MESOSCALE DISCUSSION 0761
NWS STORM PREDICTION CENTER NORMAN OK
0236 PM CDT THU MAY 12 2011

AREAS AFFECTED...ERN OH THROUGH EXTREME WRN PA AND NRN AND CNTRL WV

CONCERNING...SEVERE THUNDERSTORM WATCH 290...

VALID 121936Z - 122100Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 290
CONTINUES.

THREAT FOR MAINLY ISOLATED LARGE HAIL AND LOCALLY STRONG WIND GUSTS
WILL PERSIST NEXT COUPLE HOURS FROM ERN OH ...WRN PA SWD INTO CNTRL
WV.

STORMS CONTINUE REDEVELOPING...PRIMARILY IN VICINITY OF CONVECTIVE
OUTFLOW BOUNDARY THAT EXTENDS FROM NRN OH SWD THROUGH CNTRL WV.
EFFECTIVE VERTICAL SHEAR IS WEAK /20-30 KT/ DUE TO PROXIMITY OF
UPPER RIDGE...AND THIS HAS BEEN A LIMITING FACTOR FOR A MORE ROBUST
SEVERE EVENT. HOWEVER...MODERATE INSTABILITY AND 6.5-7 C/KM MID
LEVEL LAPSE RATES SUPPORT AT LEAST A MODEST THREAT FOR ISOLATED
LARGE HAIL AS WELL AS LOCALLY STRONG WIND GUSTS.

..DIAL.. 05/12/2011

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

ATTN...WFO...PBZ...RLX...CLE...ILN...

LAT...LON   41498138 40088081 38928045 38308064 38438111 39548189
            40828261 41268258 41498138

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 12, 10:30 AM EDT	Mesoscale Discussion	SPC	Ashland, Belmont, Carroll, Coshocton, Crawford, Erie and 21 more	90 min
May 12, 11:04 AM EDT	Severe Thunderstorm Watch	SPC	Ashland, Ashtabula, Athens, Belmont, Carroll, Columbiana and 39 more	8 hr
May 12, 6:52 PM EDT	Mesoscale Discussion	SPC	Ashland, Ashtabula, Belmont, Carroll, Columbiana, Coshocton and 26 more
May 12, 4:28 PM EDT	Mesoscale Discussion	SPC	McDowell, Mercer, Monroe, Summers, Wyoming	2 hr

Nearby

Mesoscale Discussions in Ohio, 2011 Mesoscale Discussions in West Virginia, 2011 Every 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.