Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 1397

July 4, 201241 counties in Ohio; Beaver County, Lawrence County, Washington County, Pennsylvania; 6 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2012, 9:48 PM EDT for 41 counties in Ohio; Beaver County, Lawrence County, Washington County, Pennsylvania; 6 counties in West Virginia. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Jul 4, 2012, 9:48 PM EDT (01:48 UTC)
Expired
Jul 4, 2012, 11:15 PM EDT
In force
87 min
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 50 counties

Athens County, OH, Belmont County, OH, Carroll County, OH, Champaign County, OH, Clark County, OH, Clinton County, OH, Columbiana County, OH, Coshocton County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Greene County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Holmes County, OH, Jefferson County, OH, Knox County, OH, Licking County, OH, Logan County, OH, Madison County, OH, Mahoning County, OH, Marion County, OH, Miami County, OH, Monroe County, OH, Morgan County, OH, Morrow County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Portage County, OH, Ross County, OH, Stark County, OH, Trumbull County, OH, Tuscarawas County, OH, Union County, OH, Vinton County, OH, Washington County, OH, Wayne County, OH, Beaver County, PA, Lawrence County, PA, Washington County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Ohio County, WV, Pleasants County, WV, Tyler County, WV

The radar

The Cleveland radar (KCLE), 144 km from the middle of the area, began a volume at 01:50 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

Cncnati-Daytn, OH (KILN), launched 00:00Z, 1.8 hours before the alert went out and 159 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, Cncnati-Daytn, OH at 00:00Z on 2012-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2070 joules per kilogram.LCLEL10008507005003002001001 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, Cncnati-Daytn, OH at 00:00Z on 2012-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.1939Sfc1 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
2070 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1974 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.7

Open this sounding in Storm Lab

The text

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

539 
ACUS11 KWNS 050149
SWOMCD
SPC MCD 050148
PAZ000-WVZ000-OHZ000-050315-

MESOSCALE DISCUSSION 1397
NWS STORM PREDICTION CENTER NORMAN OK
0848 PM CDT WED JUL 04 2012

AREAS AFFECTED...MUCH OF OH...WRN PA...NRN WV

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 050148Z - 050315Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...STORMS WILL CONTINUE SWD ACROSS OH INTO WRN PA AND NRN WV
WITH A FEW SEVERE GUSTS POSSIBLE. A WATCH MAY BE NEEDED.

DISCUSSION...STORMS HAVE FORMED A LOOSE LINE ACROSS N CNTRL OH...AND
WILL LIKELY PERSIST IN A SWD DIRECTION GIVEN MEAN WINDS ALOFT. RADAR
SHOWS SEVERAL OUTFLOWS WITH SOME INDICATING WINDS OVER 50 KT. PLENTY
OF INSTABILITY REMAINS IN PLACE AHEAD OF THESE STORMS...WITH MUCAPE
OVER 3600 NOTED ON THE 00Z ILN SOUNDING. A SEVERE THREAT WILL EXIST
WITH THESE STORMS AS THEY CONTINUE S...AS LONG AS THE OUTFLOW DOES
NOT OUTRUN THE NEWLY PROPAGATING CELLS.

..JEWELL/CORFIDI.. 07/05/2012

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

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

LAT...LON   40528414 40608317 40878204 41178140 41378053 41068019
            40508006 40028009 39778043 39358104 39198176 39198247
            39308324 39398381 39648423 39908433 40528414

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 10:19 PM EDTSevere Thunderstorm WatchSPCAdams, Athens, Auglaize, Belmont, Brown, Butler and 46 more4 hr
Jul 5, 4:12 AM EDTMesoscale DiscussionSPCCuyahoga, Erie, Huron, Lake, Lorain, Lucas and 2 more93 min
Jul 5, 6:16 AM EDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 21 more3 hr
Jul 5, 8:00 AM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Columbiana, Coshocton, Fairfield and 18 more90 min
Jul 5, 11:14 AM EDTMesoscale DiscussionSPCGallia, Lawrence91 min
Jul 5, 11:37 AM EDTSevere Thunderstorm WatchSPCLawrence7 hr
Jul 5, 3:27 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Defiance, Fulton, Hancock, Hardin and 14 more93 min
Jul 5, 5:58 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Butler, Champaign, Clark, Clermont and 33 more92 min
Jul 4, 8:05 PM EDTMesoscale DiscussionSPCBedford, Fayette, Fulton, Somerset55 min
Jul 5, 4:37 PM EDTMesoscale DiscussionSPCAdams, Blair, Centre, Cumberland, Dauphin, Franklin and 6 more113 min
Jul 5, 2:57 PM EDTMesoscale DiscussionSPCGreenbrier, McDowell, Mercer, Monroe, Summers2 hr

Nearby

Mesoscale Discussions in Ohio, 2012Mesoscale Discussions in West Virginia, 2012Mesoscale Discussions in Pennsylvania, 2012Every 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.