Alert archive / Ohio / Mesoscale Discussions in 2005

Mesoscale Discussion 608

April 20, 200517 counties in Ohio; 5 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2005, 3:05 PM EDT for 17 counties in Ohio; 5 counties in Pennsylvania. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Apr 20, 2005, 3:05 PM EDT (19:05 UTC)
Expired
Apr 20, 2005, 4:30 PM EDT
In force
85 min
Issued by
the Storm Prediction Center
All 22 counties

Ashtabula County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Cuyahoga County, OH, Geauga County, OH, Holmes County, OH, Lake County, OH, Lorain County, OH, Mahoning County, OH, Medina County, OH, Portage County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Wayne County, OH, Beaver County, PA, Crawford County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA

The radar

The Cleveland radar (KCLE), 65 km from the middle of the area, began a volume at 19:05 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

Pittsburgh, PA (KPIT), launched 12:00Z, 7.1 hours before the alert went out and 126 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 2005-04-20Temperature 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 2005-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -59 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
1809 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-59 m²/s²
0-3 km storm-relative helicity
-62 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.

000 
ACUS11 KWNS 201905
SWOMCD
SPC MCD 201905 
PAZ000-WVZ000-OHZ000-202030-

MESOSCALE DISCUSSION 0608
NWS STORM PREDICTION CENTER NORMAN OK
0205 PM CDT WED APR 20 2005

AREAS AFFECTED...NERN OH...NWRN PA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 201905Z - 202030Z

...SEVERE THUNDERSTORM WATCH MAY BE REQUIRED FOR PORTIONS OF NERN OH
AND NWRN PA...

LEADING EDGE OF WARM ADVECTION CONVECTION HAS BEEN DISPLACED INTO
CNTRL PORTIONS OF PA...WITH A NARROW AXIS OF INCREASING INSTABILITY
IN THE WAKE OF THIS ACTIVITY ACROSS NERN OH INTO NWRN PA.  IN THE
LAST HOUR...THUNDERSTORMS HAVE RECENTLY DEVELOPED OVER LAKE ERIE AND
WILL SOON MOVE ONSHORE INTO THIS ZONE OF INSTABILITY WHERE MORE THAN
ADEQUATE DEEP LAYER FLOW WILL SUPPORT ISOLATED SEVERE MULTICELL
UPDRAFTS.  LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY THREATS. 
WW MAY BE REQUIRED.

..DARROW.. 04/20/2005

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

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

41498226 42158018 41527949 40598043 40188209

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 20, 1:21 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Crawford, Darke, Hancock, Hardin and 9 more114 min
Apr 20, 1:50 PM EDTSevere Thunderstorm WatchSPCAllen, Ashland, Auglaize, Champaign, Crawford, Darke and 22 more6 hr
Apr 20, 3:35 PM EDTSevere Thunderstorm WatchSPCCarroll, Columbiana, Coshocton, Geauga, Harrison, Holmes and 9 more4 hr
Apr 20, 4:19 PM EDTMesoscale DiscussionSPCAllen, Ashland, Auglaize, Crawford, Geauga, Hancock and 12 more86 min
Apr 20, 6:37 PM EDTMesoscale DiscussionSPCAllen, Ashland, Auglaize, Carroll, Champaign, Columbiana and 33 more83 min

Nearby

Mesoscale Discussions in Ohio, 2005Mesoscale Discussions in Pennsylvania, 2005Every mesoscale discussion in 2005

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.