Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 276

March 18, 201232 counties in Ohio; 5 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2012, 7:44 PM EDT for 32 counties in Ohio; 5 counties in West Virginia. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Mar 18, 2012, 7:44 PM EDT (23:44 UTC)
Expired: Mar 18, 2012, 8:45 PM EDT
In force: 61 min
Issued by: the Storm Prediction Center

All 37 counties

Athens County, OH, Champaign County, OH, Clark County, OH, Clinton County, OH, Coshocton County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Gallia County, OH, Greene County, OH, Guernsey County, OH, Highland County, OH, Hocking County, OH, Holmes County, OH, Jackson County, OH, Knox County, OH, Licking County, OH, Madison County, OH, Meigs County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Pike County, OH, Ross County, OH, Tuscarawas County, OH, Union County, OH, Vinton County, OH, Washington County, OH, Jackson County, WV, Mason County, WV, Pleasants County, WV, Wirt County, WV, Wood County, WV

The radar

The Cincinnati radar (KILN), 133 km from the middle of the area, began a volume at 23:44 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

Cncnati-Daytn, OH (KILN), launched 12:00Z, 11.7 hours before the alert went out and 131 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: 429 J/kg
Mixed-layer CIN: -69 J/kg
Mixed-layer LCL: 1015 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 106 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.

435 
ACUS11 KWNS 182345
SWOMCD
SPC MCD 182344
WVZ000-OHZ000-190045-

MESOSCALE DISCUSSION 0276
NWS STORM PREDICTION CENTER NORMAN OK
0644 PM CDT SUN MAR 18 2012

AREAS AFFECTED...OH...WRN PORTIONS OF WV

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 182344Z - 190045Z

THUNDERSTORMS CAPABLE OF HAIL AND STRONG/GUSTY WINDS MAY CONTINUE TO
FORM OVER THE NEXT FEW HOURS...QUICKLY DIMINISHING IN STRENGTH AS
THEY PROGRESS EWD TOWARDS PA/WV. GIVEN ISOLATED COVERAGE OF SEVERE
STORMS...A WW IS NOT ANTICIPATED.

THUNDERSTORMS CONTINUE TO FORM ALONG THE SRN PERIPHERY OF A WEAK MCV
FEATURE...ALONG A SUBTLE THERMAL W-E THERMAL GRADIENT AND AN AREA OF
N-S SURFACE CONFLUENCE NOTED THROUGH CNTRL OH. DEW POINTS IN THE MID
TO UPPER 50S IN COMBINATION WITH SEASONABLY COOL TEMPERATURES ALOFT
ARE CONTRIBUTING TO SUFFICIENT INSTABILITY FOR OCCASIONALLY ROBUST
UPDRAFTS...WITH A SEMI ORGANIZED NATURE OWING TO NEAR 30 KTS
EFFECTIVE SHEAR. HOWEVER...INSTABILITY QUICKLY DIMINISHES FARTHER E
ACROSS OH/WV...AND WILL RAPIDLY CAUSE ANY ONGOING STORMS TO DECREASE
IN INTENSITY AS THEY PROGRESS INTO A MORE STABLE AIR MASS.
ADDITIONAL WEAKENING IS LIKELY AS DIURNAL COOLING CONTINUES TO
STABILIZE THE BOUNDARY LAYER. GIVEN THE LIMITED SPATIO-TEMPORAL
THREAT...A WW IS NOT ANTICIPATED.

..HURLBUT.. 03/18/2012

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

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

LAT...LON   40678164 40148117 39618093 39058111 38708193 38888266
            39198363 39578427 40328414 40308274 40598230 40678164

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 18, 1:49 PM EDT	Mesoscale Discussion	SPC	Adams, Brown, Butler, Champaign, Clark, Clermont and 16 more	2 hr

Nearby

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