Alert archive / Ohio / Mesoscale Discussions in 2003
Mesoscale Discussion 942
The Storm Prediction Center issued this mesoscale discussion at May 11, 2003, 10:30 AM EDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 11, 2003, 10:30 AM EDT (14:30 UTC)
- Expired
- May 11, 2003, 12:30 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 77 counties
Allegany County, NY, Cattaraugus County, NY, Chautauqua County, NY, Erie County, NY, Genesee County, NY, Orleans County, NY, Wyoming County, NY, Ashland County, OH, Ashtabula County, OH, Athens County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Cuyahoga County, OH, Geauga County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Holmes County, OH, Jefferson County, OH, Knox County, OH, Lake County, OH, Mahoning County, OH, Medina County, OH, Meigs County, OH, Monroe 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, Washington County, OH, Wayne County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Cambria County, PA, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Crawford County, PA, Elk County, PA, Erie County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Doddridge County, WV, Hancock County, WV, Harrison County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Pleasants County, WV, Ritchie County, WV, Taylor County, WV, Tyler County, WV, Wetzel County, WV, Wirt County, WV, Wood County, WV
The radar
The Pittsburgh radar (KPBZ), 83 km from the middle of the area, began a volume at 14:29 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, 2.5 hours before the alert went out and 96 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
- 1410 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 703 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 188 m²/s²
- 0-3 km storm-relative helicity
- 137 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 4.0
The text
As transmitted, in the capitals the NWS used until 2016.
687 ACUS11 KWNS 111431 SWOMCD SPC MCD 111430 PAZ000-NYZ000-MDZ000-WVZ000-OHZ000-111630- MESOSCALE DISCUSSION 0942 NWS STORM PREDICTION CENTER NORMAN OK 0930 AM CDT SUN MAY 11 2003 AREAS AFFECTED...ERN OH...WRN PA...WRN NY...NRN WV CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 111430Z - 111630Z SEVERE THUNDERSTORM DEVELOPMENT POSSIBLE IN THE NEXT FEW HOURS. WW WILL LIKELY BE REQUIRED SOON. VISIBLE SATELLITE IMAGERY CLEARLY SHOWS SURFACE COLD FRONT OVER CENTRAL OH...WITH LINE OF CU/TCU ALONG BOUNDARY. CLOUDS HAVE ERODED AS MUCH AS 150 MILES AHEAD OF FRONT...ALLOWING AREA TO DESTABILIZE RAPIDLY. SURFACE DEWPOINTS ARE NOW IN THE MID 60S...AND SBCAPE VALUES RANGE FROM 1000-2000 J/KG. STRONG SURFACE PRESSURE FALL-RISE COUPLET ALONG FRONT SUGGESTS LARGE SCALE FORCING IS PRESENT...AND THAT THUNDERSTORMS WILL LIKELY DEVELOP IN THE NEXT 2-3 HOURS. LOW LEVEL AND DEEP LAYER VERTICAL SHEAR PROFILES APPEAR FAVORABLE FOR INITIAL SUPERCELL DEVELOPMENT CAPABLE OF ISOLATED TORNADOES AND DAMAGING WINDS. ..HART.. 05/11/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BUF...CTP...PBZ...RLX...CLE...ILN... 43367812 42307776 40327851 39098042 38838191 39248253 40468242 41488212 42348033 43217885
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 10:07 AM EDT | Mesoscale Discussion | SPC | Allegany, Broome, Cayuga, Chemung, Chenango, Cortland and 19 more | 113 min |
| May 11, 11:45 AM EDT | Tornado Watch | SPC | Allegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 2 more | 5 hr |
| May 11, 12:32 PM EDT | Mesoscale Discussion | SPC | Broome, Cayuga, Chemung, Chenango, Cortland, Jefferson and 13 more | 118 min |
| May 11, 1:50 PM EDT | Tornado Watch | SPC | Broome, Cayuga, Chemung, Chenango, Cortland, Herkimer and 14 more | 5 hr |
| May 11, 2:52 PM EDT | Mesoscale Discussion | SPC | Allegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 3 more | 113 min |
| May 11, 3:54 PM EDT | Mesoscale Discussion | SPC | Broome, Cayuga, Chemung, Chenango, Cortland, Herkimer and 14 more | 2 hr |
| May 10, 11:40 PM EDT | Mesoscale Discussion | SPC | Williams | 2 hr |
| May 11, 12:00 AM EDT | Tornado Watch | SPC | Defiance, Paulding, Van Wert, Williams | 6 hr |
| May 11, 12:28 AM EDT | Mesoscale Discussion | SPC | Adams, Allen, Ashland, Auglaize, Brown, Butler and 44 more | 2 hr |
| May 10, 9:28 PM EDT | Mesoscale Discussion | SPC | Boone, Clay, Fayette, Kanawha, Lincoln, Logan and 6 more | 62 min |
| May 11, 5:16 AM EDT | Mesoscale Discussion | SPC | Wayne | 59 min |
| May 11, 6:05 AM EDT | Severe Thunderstorm Watch | SPC | Wayne | 4 hr |
| May 11, 3:18 PM EDT | Mesoscale Discussion | SPC | Berkeley, Jefferson, Morgan | 117 min |
Nearby
Mesoscale Discussions in Ohio, 2003Mesoscale Discussions in Pennsylvania, 2003Mesoscale Discussions in West Virginia, 2003Every mesoscale discussion in 2003
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.