Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 2174

December 17, 20128 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Dec 17, 2012, 3:12 PM EST for 8 counties in Ohio. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Dec 17, 2012, 3:12 PM EST (20:12 UTC)
Expired: Dec 17, 2012, 5:15 PM EST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Adams County, OH, Brown County, OH, Clermont County, OH, Highland County, OH, Jackson County, OH, Pike County, OH, Ross County, OH, Scioto County, OH

The radar

The Cincinnati radar (KILN), 48 km from the middle of the area, began a volume at 20:15 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, 8.2 hours before the alert went out and 48 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: 1 J/kg
Mixed-layer CIN: -102 J/kg
Mixed-layer LCL: 577 m above ground
0-6 km bulk shear: 74 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 71 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.

433 
ACUS11 KWNS 172013
SWOMCD
SPC MCD 172012
OHZ000-KYZ000-172215-

MESOSCALE DISCUSSION 2174
NWS STORM PREDICTION CENTER NORMAN OK
0212 PM CST MON DEC 17 2012

AREAS AFFECTED...PARTS OF SOUTHWEST AND SOUTH CENTRAL OHIO

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 172012Z - 172215Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED SVR STORM OR TWO WILL BE POSSIBLE THIS
AFTERNOON. THE SPORADIC/MARGINAL NATURE OF ANY SVR THREAT WILL
LIKELY PRECLUDE THE NEED FOR A WW.

DISCUSSION...THE LEADING EDGE OF STRONG ASCENT ACCOMPANYING A
MID-LEVEL VORT MAX APPROACHING THE AREA WILL CONTINUE TO SUPPORT AN
UPTICK IN CONVECTION NEAR AND NORTH OF THE OHIO RIVER. THE INFLUX OF
7-7.5 C/KM 700-500-MB LAPSE RATES SUPPORTING UPWARDS OF 500 J/KG OF
MUCAPE WILL PROMOTE INTENSE UPDRAFTS. AND...WITH OVER 35 KT OF DEEP
SHEAR SAMPLED BY WILMINGTON OHIO VWP DATA...ORGANIZED STORM
STRUCTURES MAY EVOLVE...WHICH WILL BE CAPABLE OF PRODUCING SMALL
HAIL AND/OR STRONG WIND GUSTS. AN ISOLATED SVR STORM OR TWO MAY ALSO
OCCUR WITHIN AN AREA BOUNDED BY THE FAR ERN SIDE OF
CINCINNATI...CHILLICOTHE...AND PORTSMOUTH. WITHIN THIS
AREA...POCKETS OF INSOLATION/DIABATIC HEATING HAVE ALLOWED SFC
TEMPERATURES TO WARM INTO THE 50S...SUPPORTING MEAGER SFC-BASED
BUOYANCY. HOWEVER...THE RELATIVELY COOL AIR MASS SHOULD PREVENT A
MORE SUBSTANTIAL SVR THREAT FROM EVOLVING.

..COHEN/CORFIDI.. 12/17/2012

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

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

LAT...LON   38858420 39108449 39298437 39348406 39408351 39508285
            39298252 38878251 38698282 38668336 38698379 38858420

Nearby

Mesoscale Discussions in Ohio, 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.