Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 649

May 1, 2012Boyd County, Kentucky; 14 counties in Ohio; 7 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 1, 2012, 6:13 PM EDT for Boyd County, Kentucky; 14 counties in Ohio; 7 counties in West Virginia. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: May 1, 2012, 6:13 PM EDT (22:13 UTC)
Expired: May 1, 2012, 7:15 PM EDT
In force: 62 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 22 counties

Boyd County, KY, Athens County, OH, Fairfield County, OH, Gallia County, OH, Hocking County, OH, Jackson County, OH, Lawrence County, OH, Meigs County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Vinton County, OH, Washington County, OH, Cabell County, WV, Jackson County, WV, Mason County, WV, Pleasants County, WV, Putnam County, WV, Wirt County, WV, Wood County, WV

The radar

The Charleston,WV radar (KRLX), 71 km from the middle of the area, began a volume at 22:13 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.

Tornado Watch 222May 1, 6:30 PM EDT

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 12:00Z, 10.2 hours before the alert went out and 168 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 15 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 516 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 93 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.

777 
ACUS11 KWNS 012213
SWOMCD
SPC MCD 012213 
WVZ000-OHZ000-KYZ000-012315-

MESOSCALE DISCUSSION 0649
NWS STORM PREDICTION CENTER NORMAN OK
0513 PM CDT TUE MAY 01 2012

AREAS AFFECTED...SRN/SERN OH...WRN WV

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 012213Z - 012315Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...CLUSTERS OF SUPERCELLS MAY SPREAD EWD INTO SERN OH AND WRN
WV DURING THE EVENING. AREA IS BEING MONITORED FOR A WW.

DISCUSSION...REGIONAL RADAR IMAGERY SHOWS CLUSTERS OF SUPERCELLS
OVER SWRN OH/NRN KY...MOVING E AT 30 KT ACROSS TORNADO WATCH 218.
DOWNSTREAM AIRMASS OVER SERN OH AND WRN WV IS MODERATELY UNSTABLE
ALONG AN E-W SURFACE BAROCLINIC ZONE...WITH MLCAPE VALUES RANGING
FROM 500-1500 J/KG. IN ADDITION...ILN VWP SHOWS STRONGLY VEERING
DEEP-LAYER WIND PROFILES FAVORABLE FOR SUPERCELLS. THUS...THREAT FOR
A FEW TORNADOES...LARGE HAIL AND DAMAGING WIND GUSTS MAY SPREAD E OF
WW 218.

..GARNER/CORFIDI.. 05/01/2012

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

ATTN...WFO...PBZ...RLX...ILN...

LAT...LON   38478150 38248216 38398285 40058289 39938086 38478150

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 30, 9:07 PM EDT	Mesoscale Discussion	SPC	Anderson, Bath, Boone, Bourbon, Boyd, Boyle and 52 more	53 min
May 1, 1:33 PM EDT	Mesoscale Discussion	SPC	Adair, Allen, Barren, Butler, Casey, Clinton and 17 more	117 min
May 1, 2:44 PM EDT	Severe Thunderstorm Watch	SPC	Adair, Allen, Anderson, Barren, Bath, Bourbon and 59 more	6 hr
May 1, 3:01 PM EDT	Tornado Watch	SPC	Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 8 more	7 hr
May 1, 6:31 PM EDT	Tornado Watch	SPC	Boone, Boyd, Bracken, Campbell, Carroll, Carter and 9 more	5 hr
May 1, 2:44 PM EDT	Mesoscale Discussion	SPC	Butler, Clark, Darke, Greene, Hamilton, Miami and 3 more	61 min
May 1, 12:43 PM EDT	Mesoscale Discussion	SPC	Monroe	2 hr

Nearby

Mesoscale Discussions in Ohio, 2012 Mesoscale Discussions in West Virginia, 2012 Mesoscale Discussions in Kentucky, 2012 Every 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.