Alert archive / Ohio / Mesoscale Discussions in 2014

Mesoscale Discussion 1313

July 8, 201424 counties in Ohio; Mercer County, Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Jul 8, 2014, 8:58 AM EDT for 24 counties in Ohio; Mercer County, Pennsylvania. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Jul 8, 2014, 8:58 AM EDT (12:58 UTC)
Expired: Jul 8, 2014, 10:00 AM EDT
In force: 62 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 25 counties

Ashland County, OH, Crawford County, OH, Cuyahoga County, OH, Erie County, OH, Geauga County, OH, Hancock County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lorain County, OH, Mahoning County, OH, Marion County, OH, Medina County, OH, Morrow 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, Wayne County, OH, Wyandot County, OH, Mercer County, PA

The radar

The Cleveland radar (KCLE), 51 km from the middle of the area, began a volume at 13:00 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

Detroit, MI (KDTX), launched 12:00Z, 1.0 hours before the alert went out and 194 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: 432 J/kg
Mixed-layer CIN: -64 J/kg
Mixed-layer LCL: 976 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

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

621 
ACUS11 KWNS 081258
SWOMCD
SPC MCD 081258 
PAZ000-OHZ000-081400-

MESOSCALE DISCUSSION 1313
NWS STORM PREDICTION CENTER NORMAN OK
0758 AM CDT TUE JUL 08 2014

AREAS AFFECTED...NORTHERN OH/FAR WESTERN PA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 081258Z - 081400Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...LOCALLY STRONG WIND GUSTS MAY BE POSSIBLE THIS MORNING
ACROSS NORTHERN OH INTO FAR WESTERN PA. A WATCH DOES NOT APPEAR
LIKELY IN THE SHORT-TERM GIVEN THE INITIAL MARGINALITY OF THE
SCENARIO...BUT CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED
THROUGH THE MORNING.

DISCUSSION...AHEAD OF AN MCV ACROSS INDIANA...A LINE OF CONVECTION
FOCUSED ALONG OUTFLOW /REMNANTS OF AN OVERNIGHT SQUALL LINE/
CONTINUES TO STEADILY PROGRESS NORTHEASTWARD ACROSS
NORTHWEST/NORTH-CENTRAL OH AS OF 13Z. THE PRECEDING BOUNDARY LAYER
IS SEMI-STABLE AT MID-MORNING WITH PRECEDING CLOUD COVER READILY
EVIDENT IN VISIBLE SATELLITE IMAGERY ACROSS OH INTO PA.
NONETHELESS...THE FORWARD PROGRESSION OF THE CONVECTIVE LINE/COLD
POOL COULD ACCOUNT FOR LOCALLY STRONG WIND GUSTS THIS MORNING.
BEHIND THESE STORMS...WSR-88D VWP DATA FROM INDIANAPOLIS/WILMINGTON
INDICATE AS MUCH 50 KT WESTERLY WINDS WITHIN THE LOWEST 2-4 KM. THE
OVERALL SEVERE THREAT...INCLUDING A MORE PREVALENT DAMAGING WIND
POTENTIAL...COULD INCREASE ACROSS THE REGION BY LATE
MORNING/AFTERNOON AS THE BOUNDARY LAYER WARMS AND DESTABILIZES.

..GUYER/MEAD.. 07/08/2014

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

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

LAT...LON   41158382 41558319 41838035 41168021 40148283 41158382

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 8, 11:29 AM EDT	Mesoscale Discussion	SPC	Ashland, Ashtabula, Belmont, Carroll, Champaign, Clark and 42 more	91 min
Jul 8, 1:04 PM EDT	Severe Thunderstorm Watch	SPC	Ashland, Ashtabula, Athens, Belmont, Carroll, Columbiana and 29 more	7 hr
Jul 8, 4:00 PM EDT	Mesoscale Discussion	SPC	Allegheny, Armstrong, Bedford, Blair, Bradford, Butler and 35 more	90 min
Jul 8, 4:42 PM EDT	Mesoscale Discussion	SPC	Adams, Berks, Bucks, Carbon, Chester, Cumberland and 15 more	63 min
Jul 8, 5:05 PM EDT	Severe Thunderstorm Watch	SPC	Berks, Bucks, Carbon, Chester, Delaware, Lancaster and 7 more	5 hr
Jul 8, 6:27 PM EDT	Severe Thunderstorm Watch	SPC	Pike, Wayne	6 hr
Jul 8, 7:44 PM EDT	Mesoscale Discussion	SPC	Berks, Bucks, Carbon, Chester, Columbia, Dauphin and 16 more	61 min

Nearby

Mesoscale Discussions in Ohio, 2014 Mesoscale Discussions in Pennsylvania, 2014 Every mesoscale discussion in 2014

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.