Alert archive / Ohio / Mesoscale Discussions in 2011

Mesoscale Discussion 765

May 12, 201132 counties in Ohio; 4 counties in Pennsylvania; 5 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 12, 2011, 6:52 PM EDT for 32 counties in Ohio; 4 counties in Pennsylvania; 5 counties in West Virginia. It was in force for .

The area

The outline as issued.

The facts

Issued
May 12, 2011, 6:52 PM EDT (22:52 UTC)
Expired
May 12, 2011, 6:45 PM EDT
In force
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 290
All 41 counties

Ashland County, OH, Ashtabula County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Crawford County, OH, Cuyahoga County, OH, Erie County, OH, Geauga County, OH, Guernsey County, OH, Harrison County, OH, Holmes County, OH, Huron County, OH, Jefferson County, OH, Lake County, OH, Lorain County, OH, Mahoning County, OH, Medina County, OH, Monroe County, OH, Noble County, OH, Ottawa County, OH, Portage County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Wayne County, OH, Wood County, OH, Beaver County, PA, Greene County, PA, Lawrence County, PA, Mercer County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Ohio County, WV, Wetzel County, WV

The radar

The Cleveland radar (KCLE), 86 km from the middle of the area, began a volume at 22:52 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 nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 10.9 hours before the alert went out and 127 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, Pittsburgh, PA at 12:00Z on 2011-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Pittsburgh, PA at 12:00Z on 2011-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 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
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.

467 
ACUS11 KWNS 122253
SWOMCD
SPC MCD 122252 COR
PAZ000-WVZ000-OHZ000-122245-

MESOSCALE DISCUSSION 0765
NWS STORM PREDICTION CENTER NORMAN OK
0552 PM CDT THU MAY 12 2011

AREAS AFFECTED...NERN HALF OF OH / FAR WRN PA / WV PANHANDLE

CONCERNING...SEVERE THUNDERSTORM WATCH 290...

VALID 122252Z - 122245Z

CORRECTED FOR MCD GRAPHIC

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 290
CONTINUES.

WW 290 WILL BE ALLOWED TO EXPIRE AT 23Z.  AN ISOLD STRONG WIND GUST
MAY OCCUR WITH THE STRONGER CORES FOR THE NEXT HR OR SO.

WATER VAPOR IMAGERY SHOWS A WEAK MID LEVEL PERTURBATION CRESTING THE
UPPER RIDGE OVER SWRN ONTARIO/LAKE ERIE THAT HAS BEEN PARTIALLY
RESPONSIBLE FOR THIS AFTERNOON/S STORM CLUSTER IN THE UPPER OH
VALLEY.  SURFACE ANALYSIS PLACES A GENERALLY N-S OUTFLOW BOUNDARY
FROM 30 MI NW MFD /WHERE STORMS ARE TRYING TO REGENERATE/ SSEWD TO
NEAR ZZV AND SWD INVOF CRW.  CONVECTIVE OVERTURNING OF THE AIRMASS E
OF THE BOUNDARY WHERE THE ONGOING STORMS ARE LOCATED WILL ACT TO
CONTINUE TO LESSEN STORM INTENSITY AS BUOYANCY IS FURTHER
MARGINALIZED.  STRONGLY VEERING WIND PROFILE /ALBEIT WEAK/ WILL
LIMIT STORM ORGANIZATION POTENTIAL AND STORM CLUSTERS OVER THE
REGION ARE EXPECTED TO WEAKEN THIS EVENING DUE IN PART TO LOSS OF
HEATING.

..SMITH.. 05/12/2011

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

ATTN...WFO...PBZ...CLE...

LAT...LON   41638376 41728193 42258015 41118009 40358045 39798001
            39538024 39568063 39748142 40018188 40528244 40938351
            41638376

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 12, 10:30 AM EDTMesoscale DiscussionSPCAshland, Belmont, Carroll, Coshocton, Crawford, Erie and 21 more90 min
May 12, 11:04 AM EDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Athens, Belmont, Carroll, Columbiana and 39 more8 hr
May 12, 3:36 PM EDTMesoscale DiscussionSPCAshland, Belmont, Carroll, Coshocton, Guernsey, Harrison and 12 more84 min
May 12, 4:28 PM EDTMesoscale DiscussionSPCMcDowell, Mercer, Monroe, Summers, Wyoming2 hr

Nearby

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