Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 1349

July 1, 201210 counties in Ohio; 10 counties in Pennsylvania; Brooke County, Hancock County, Ohio County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 7:22 PM EDT for 10 counties in Ohio; 10 counties in Pennsylvania; Brooke County, Hancock County, Ohio County, West Virginia. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Jul 1, 2012, 7:22 PM EDT (23:22 UTC)
Expired
Jul 1, 2012, 8:45 PM EDT
In force
83 min
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 23 counties

Carroll County, OH, Columbiana County, OH, Geauga County, OH, Harrison County, OH, Jefferson County, OH, Mahoning County, OH, Portage County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Crawford County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Washington County, PA, Brooke County, WV, Hancock County, WV, Ohio County, WV

The radar

The Pittsburgh radar (KPBZ), 36 km from the middle of the area, began a volume at 23:25 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, 11.4 hours before the alert went out and 52 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 2012-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 529 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, Pittsburgh, PA at 12:00Z on 2012-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.19395878Sfc1 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
529 J/kg
Mixed-layer CIN
-169 J/kg
Mixed-layer LCL
1414 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.9

Open this sounding in Storm Lab

The text

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

785 
ACUS11 KWNS 012323
SWOMCD
SPC MCD 012322
PAZ000-WVZ000-OHZ000-020045-

MESOSCALE DISCUSSION 1349
NWS STORM PREDICTION CENTER NORMAN OK
0622 PM CDT SUN JUL 01 2012

AREAS AFFECTED...NERN OH...WRN PA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 012322Z - 020045Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A SVR TSTM WATCH MAY BE NEEDED DOWNSTREAM OF THE
CNTRL/N-CNTRL OHIO CONVECTIVE LINE. TRENDS WILL CONTINUE TO BE
MONITORED.

DISCUSSION...CONVECTION CONTINUES TO ELONGATE ALONG THE N-S-ORIENTED
LEADING EDGE OF A COLD POOL MATERIALIZING ACROSS THE WRN HALF OF
OHIO OWING TO BOTH NRN AND CNTRL OHIO CONVECTIVE CLUSTERS. MODERATE
MID-LEVEL FLOW PER CLEVELAND VWP DATA OFFERING 35-50 KT OF EFFECTIVE
BULK SHEAR IS PRESENT. COLD POOL/SHEAR INTERACTIONS MAY BE ADEQUATE
TO CONTINUE TO SUPPORT UPSCALE CONVECTIVE GROWTH AS ACTIVITY
APPROACHES NERN OH AND EVENTUALLY WRN PA. AS SUCH...SOME POTENTIAL
FOR A RELATIVELY MORE SUBSTANTIAL DMGG WIND THREAT MAY ENSUE.
HOWEVER...RELATIVELY MORE LIMITED INSTABILITY NORTH OF A DIFFUSE
STATIONARY FRONT MAY HINDER MORE ROBUST CONVECTIVE GROWTH DESPITE
ENHANCEMENT OFFERED BY COLD POOL/SHEAR BALANCE. AS SUCH...WW
ISSUANCE DOWNSTREAM IS NOT CERTAIN...BUT IS POSSIBLE.

..COHEN/HART.. 07/01/2012

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

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

LAT...LON   39978043 40298142 41198162 41878088 41947969 41517927
            40657942 40187977 39978043

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 1:16 PM EDTSevere Thunderstorm WatchSPCAllen, Auglaize, Champaign, Clark, Darke, Defiance and 11 more6 hr
Jul 1, 3:56 PM EDTMesoscale DiscussionSPCAllen, Athens, Auglaize, Champaign, Clark, Clinton and 36 more94 min
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, 5:59 PM EDTSevere Thunderstorm WatchSPCAdams, Brown, Butler, Clermont, Hamilton, Scioto5 hr
Jul 1, 6:47 PM EDTMesoscale DiscussionSPCAshland, Coshocton, Crawford, Erie, Hancock, Holmes and 14 more58 min
Jul 1, 12:11 PM EDTMesoscale DiscussionSPCBerks, Bucks, Carbon, Chester, Columbia, Dauphin and 16 more64 min
Jul 1, 1:35 PM EDTSevere Thunderstorm WatchSPCBerks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 1 more6 hr
Jul 1, 3:25 PM EDTMesoscale DiscussionSPCBerks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 2 more95 min
Jul 1, 9:27 AM EDTMesoscale DiscussionSPCMcDowell, Mercer, Monroe, Wyoming63 min
Jul 1, 9:44 AM EDTSevere Thunderstorm WatchSPCMcDowell, Mercer5 hr

Nearby

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