Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 1339

July 1, 201226 counties in Indiana; 42 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 3:56 PM EDT for 26 counties in Indiana; 42 counties in Ohio. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Jul 1, 2012, 3:56 PM EDT (19:56 UTC)
Expired
Jul 1, 2012, 5:30 PM EDT
In force
94 min
Issued by
the Storm Prediction Center
All 68 counties

Adams County, IN, Allen County, IN, Blackford County, IN, Cass County, IN, DeKalb County, IN, Delaware County, IN, Elkhart County, IN, Fulton County, IN, Grant County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jay County, IN, Kosciusko County, IN, LaGrange County, IN, Madison County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Randolph County, IN, Steuben County, IN, Tipton County, IN, Wabash County, IN, Wayne County, IN, Wells County, IN, Whitley County, IN, Allen County, OH, Athens County, OH, Auglaize County, OH, Champaign County, OH, Clark County, OH, Clinton County, OH, Coshocton County, OH, Crawford County, OH, Darke County, OH, Defiance County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Greene County, OH, Hancock County, OH, Hardin County, OH, Hocking County, OH, Jackson County, OH, Knox County, OH, Licking County, OH, Logan County, OH, Madison County, OH, Marion County, OH, Meigs County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Morgan County, OH, Morrow County, OH, Muskingum County, OH, Paulding County, OH, Perry County, OH, Pickaway County, OH, Preble County, OH, Putnam County, OH, Ross County, OH, Shelby County, OH, Union County, OH, Van Wert County, OH, Vinton County, OH, Wyandot County, OH

The radar

The Cincinnati radar (KILN), 98 km from the middle of the area, began a volume at 19:57 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 12:00Z, 7.9 hours before the alert went out and 97 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 12:00Z on 2012-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2142 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, Cncnati-Daytn, OH at 12:00Z on 2012-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 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
2142 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
1001 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
113 m²/s²
Significant tornado parameter
0.7
Supercell composite
5.0

Open this sounding in Storm Lab

The text

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

181 
ACUS11 KWNS 011957
SWOMCD
SPC MCD 011956
OHZ000-INZ000-MIZ000-012130-

MESOSCALE DISCUSSION 1339
NWS STORM PREDICTION CENTER NORMAN OK
0256 PM CDT SUN JUL 01 2012

AREAS AFFECTED...NERN AND E-CNTRL IND / MUCH OF WRN AND SRN OH

CONCERNING...SEVERE THUNDERSTORM WATCH 443...

VALID 011956Z - 012130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 443
CONTINUES.

SUMMARY...SEVERE TSTM CLUSTER OVER N-CNTRL AND NRN IND IS EXPECTED
TO MOVE INTO WRN OH AND THEN INTO CNTRL-SRN OH AND POSE A
STRONG-SEVERE WIND GUST RISK AND ASSOCIATED WIND DAMAGE THREAT.  A
NEW SEVERE TSTM WATCH WILL NEED TO BE CONSIDERED OVER THE NEXT FEW
HOURS DOWNSTREAM OF THE EXISTING WATCH FOR AREAS OVER CNTRL AND
S-CNTRL OH AND POSSIBLY WV.

DISCUSSION...VISIBLE SATELLITE SHOWS A WNW-ESE BAND OF ACCAS AND AN
AGITATED CU FIELD OVER SWRN AND W-CNTRL OH TO THE E OF THE STRONG TO
SEVERE STORM COMPLEX OVER NRN IND.  CLOUD-BEARING UNIDIRECTIONAL
WNWLY FLOW WILL ACT TO AID IN MOVING THE EXISTING STORMS ESE DOWN A
VERY UNSTABLE CORRIDOR FROM E-CNTRL IND INTO SERN OH.  OBSERVED
STORM AND COLD POOL MOTION AROUND 280/35 KTS AND LINEAR
EXTRAPOLATION SUGGEST THE LEADING EDGE OF THE STORM COMPLEX WOULD
EXIT THE EXISTING SEVERE WATCH BY 23Z.  WITH SURFACE-H5 LAPSE RATE
LAYER EXCEEDING 8 DEG C/KM ON AREA FORECAST SOUNDINGS...THE
MAINTENANCE OF THE EXISTING COMPLEX AND WIND DAMAGE POTENTIAL WILL
LIKELY CONTINUE WELL INTO OH...AS 25-50 KT MID-UPPER LEVEL FLOW
SUPPORTS STORM LONGEVITY/SEVERITY.

..SMITH/THOMPSON.. 07/01/2012

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

ATTN...WFO...PBZ...RLX...CLE...ILN...IWX...IND...

LAT...LON   40098591 40958664 41918573 40798257 40228163 39378150
            38878240 40098591

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 12:33 PM EDTMesoscale DiscussionSPCAdams, Benton, Blackford, Boone, Carroll, Cass and 34 more57 min
Jul 1, 1:16 PM EDTSevere Thunderstorm WatchSPCAdams, Allen, Benton, Blackford, Boone, Carroll and 38 more6 hr
Jul 1, 2:59 PM EDTMesoscale DiscussionSPCPosey61 min
Jul 1, 5:59 PM EDTSevere Thunderstorm WatchSPCClark, Crawford, Dearborn, Dubois, Floyd, Franklin and 9 more5 hr
Jul 1, 4:32 PM EDTSevere Thunderstorm WatchSPCAthens, Belmont, Carroll, Clinton, Columbiana, Coshocton and 28 more6 hr
Jul 1, 5:19 PM EDTMesoscale DiscussionSPCAshland, Crawford, Erie, Fulton, Hancock, Henry and 16 more56 min
Jul 1, 5:40 PM EDTSevere Thunderstorm WatchSPCAshland, Crawford, Cuyahoga, Erie, Geauga, Hancock and 19 more4 hr
Jul 1, 5:45 PM EDTMesoscale DiscussionSPCAthens, Champaign, Clark, Clinton, Darke, Delaware and 20 more60 min
Jul 1, 6:47 PM EDTMesoscale DiscussionSPCAshland, Coshocton, Crawford, Erie, Hancock, Holmes and 14 more58 min
Jul 1, 7:22 PM EDTMesoscale DiscussionSPCCarroll, Columbiana, Geauga, Harrison, Jefferson, Mahoning and 4 more83 min

Nearby

Mesoscale Discussions in Ohio, 2012Mesoscale Discussions in Indiana, 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.