Alert archive / Ohio / Mesoscale Discussions in 2012
Mesoscale Discussion 953
The Storm Prediction Center issued this mesoscale discussion at May 29, 2012, 9:48 AM EDT for 24 counties in Ohio; 14 counties in Pennsylvania; Brooke County, Hancock County, West Virginia. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- May 29, 2012, 9:48 AM EDT (13:48 UTC)
- Expired
- May 29, 2012, 11:15 AM EDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 40 counties
Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Fairfield County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Holmes County, OH, Jefferson County, OH, Knox County, OH, Licking County, OH, Mahoning County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Portage County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Vinton County, OH, Wayne County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Clearfield County, PA, Crawford County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Brooke County, WV, Hancock County, WV
The radar
The Pittsburgh radar (KPBZ), 70 km from the middle of the area, began a volume at 13:50 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
Pittsburgh, PA (KPIT), launched 12:00Z, 1.8 hours before the alert went out and 83 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.
- Mixed-layer CAPE
- 1123 J/kg
- Mixed-layer CIN
- -67 J/kg
- Mixed-layer LCL
- 1071 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 96 m²/s²
- 0-3 km storm-relative helicity
- 114 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 2.3
The text
As transmitted, in the capitals the NWS used until 2016.
369
ACUS11 KWNS 291349
SWOMCD
SPC MCD 291348
PAZ000-NYZ000-WVZ000-OHZ000-291515-
MESOSCALE DISCUSSION 0953
NWS STORM PREDICTION CENTER NORMAN OK
0848 AM CDT TUE MAY 29 2012
AREAS AFFECTED...ERN OH...NW PA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 291348Z - 291515Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...AN ISOLATED THREAT FOR DAMAGING WIND GUSTS AND HAIL WILL
LIKELY INCREASE LATE THIS MORNING INTO THE EARLY AFTERNOON. WW
ISSUANCE MAY BECOME NECESSARY AS STORMS INTENSIFY.
DISCUSSION...A NEARLY CONTINUOUS LINE OF THUNDERSTORMS IS ONGOING
FROM SW ONTARIO SSWWD ACROSS WRN OH INTO NRN KY LOCATED ALONG THE
AXIS OF A 30 TO 40 KT LOW-LEVEL JET. THIS FEATURE ALONG WITH
LARGE-SCALE ASCENT ASSOCIATED WITH AN UPPER-LEVEL SYSTEM TO THE
NORTHWEST IS SUPPORTING THUNDERSTORM DEVELOPMENT ACROSS THE OH
VALLEY. TO THE EAST OF THE STORMS...VISIBLE SATELLITE IMAGERY SHOWS
SOME CLEARING SUGGESTING THAT SFC TEMPS WILL WARM SUFFICIENTLY TO
HELP GRADUALLY RAMP UP THE SEVERE THREAT OVER THE NEXT FEW HOURS. IN
ADDITION...REGIONAL WSR-88D VWPS IN THE UPPER OH VALLEY SHOW 40 TO
45 KT OF 0-6 KM SHEAR WHICH COMBINED WITH VEERED LOW-LEVEL WINDS
SHOULD BE FAVORABLE FOR SEVERE MULTICELL LINE-SEGMENTS CAPABLE OF
PRODUCING DAMAGING WIND GUSTS. IN ADDITION...HAIL MAY ACCOMPANY THE
STRONGER CELLS AND HEAVY RAIN COULD ALSO BE PRESENT WITH THE SLOWER
MOVING STORMS.
..BROYLES/WEISS.. 05/29/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BUF...CTP...PBZ...RLX...CLE...ILN...
LAT...LON 42087941 41948035 41138183 40648245 40108279 39688290
39408289 39238250 39408204 39948095 40457998 41037839
41717859 42087941SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 29, 10:27 AM EDT | Severe Thunderstorm Watch | SPC | Ashtabula, Belmont, Carroll, Columbiana, Coshocton, Guernsey and 10 more | 5 hr |
| May 29, 1:25 PM EDT | Mesoscale Discussion | SPC | Belmont, Carroll, Columbiana, Coshocton, Guernsey, Harrison and 8 more | 65 min |
| May 29, 11:43 AM EDT | Mesoscale Discussion | SPC | Bradford, Lackawanna, Susquehanna, Wayne, Wyoming | 62 min |
| May 29, 12:01 PM EDT | Mesoscale Discussion | SPC | Bradford, Clinton, Lackawanna, Lycoming, Montour, Northumberland and 7 more | 59 min |
| May 29, 1:03 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Bedford, Berks, Blair, Bradford, Carbon and 30 more | 8 hr |
| May 29, 2:13 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bradford, Bucks, Carbon and 35 more | 62 min |
| May 29, 3:12 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bradford, Cambria and 36 more | 63 min |
| May 29, 4:40 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bucks, Carbon, Chester, Columbia and 22 more | 65 min |
| May 29, 5:54 PM EDT | Severe Thunderstorm Watch | SPC | Bucks, Chester, Delaware, Montgomery, Northampton, Philadelphia | 3 hr |
| May 29, 7:01 PM EDT | Mesoscale Discussion | SPC | Bucks, Philadelphia | 89 min |
| May 29, 4:22 PM EDT | Mesoscale Discussion | SPC | Berkeley, Hampshire, Hardy, Jefferson, Morgan, Pendleton | 53 min |
| May 29, 4:33 PM EDT | Severe Thunderstorm Watch | SPC | Berkeley, Grant, Hampshire, Hardy, Jefferson, Mineral and 2 more | 4 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.