Alert archive / Ohio / Mesoscale Discussions in 2017
Mesoscale Discussion 36
The Storm Prediction Center issued this mesoscale discussion at Jan 12, 2017, 10:42 AM EST for 5 states. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 12, 2017, 10:42 AM EST (15:42 UTC)
- Expired
- Jan 12, 2017, 1:15 PM EST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 83 counties
Clark County, IN, Dearborn County, IN, Decatur County, IN, Fayette County, IN, Franklin County, IN, Jefferson County, IN, Jennings County, IN, Ohio County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Switzerland County, IN, Union County, IN, Washington County, IN, Wayne County, IN, Boone County, KY, Bracken County, KY, Campbell County, KY, Carroll County, KY, Gallatin County, KY, Grant County, KY, Henry County, KY, Kenton County, KY, Owen County, KY, Pendleton County, KY, Trimble County, KY, Adams County, OH, Ashland County, OH, Athens County, OH, Belmont County, OH, Brown County, OH, Butler County, OH, Carroll County, OH, Champaign County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Columbiana County, OH, Coshocton County, OH, Darke County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Greene County, OH, Guernsey County, OH, Hamilton County, OH, Harrison County, OH, Highland County, OH, Hocking County, OH, Holmes County, OH, Jefferson County, OH, Knox County, OH, Licking County, OH, Logan County, OH, Madison County, OH, Mahoning County, OH, Marion County, OH, Miami County, OH, Montgomery County, OH, Morgan County, OH, Morrow County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Pike County, OH, Portage County, OH, Preble County, OH, Richland County, OH, Ross County, OH, Shelby County, OH, Stark County, OH, Summit County, OH, Tuscarawas County, OH, Union County, OH, Vinton County, OH, Warren County, OH, Wayne County, OH, Beaver County, PA, Lawrence County, PA, Brooke County, WV, Hancock County, WV
The radar
The Cincinnati radar (KILN), 53 km from the middle of the area, began a volume at 15:45 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, 3.7 hours before the alert went out and 51 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 740 m above ground
- 0-6 km bulk shear
- 60 kt
- 0-1 km storm-relative helicity
- 483 m²/s²
- 0-3 km storm-relative helicity
- 490 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
009
ACUS11 KWNS 121542
SWOMCD
SPC MCD 121542
PAZ000-WVZ000-OHZ000-KYZ000-INZ000-121815-
Mesoscale Discussion 0036
NWS Storm Prediction Center Norman OK
0942 AM CST Thu Jan 12 2017
Areas affected...Portions of OH...southeastern IN...northern
KY...western PA...western WV
Concerning...Severe potential...Watch unlikely
Valid 121542Z - 121815Z
Probability of Watch Issuance...5 percent
SUMMARY...Showers and thunderstorms crossing the middle Ohio Valley
region and vicinity may produce locally strong wind gusts through
the afternoon hours. A few marginally severe wind gusts cannot be
ruled out, and the addition of a Marginal Risk area is planned
across portions of the area and vicinity for the 1630Z Day-1
Convective Outlook. However, Watch issuance is not anticipated.
DISCUSSION...The 12Z soundings at Wilmington OH and Pittsburgh PA
sampled strong 850-mb southwesterly flow -- on the order of around
60 kt -- accompanying a LLJ overlying the local area. The related
return of marginal boundary-layer moisture -- e.g. surface dewpoints
around the middle 50s -- continues ahead of a sharp cold front
analyzed from northwest OH to southern IL. As the cold front
continues to advance into the modestly moist/marginally unstable air
across the middle OH Valley region and vicinity, and weak
pre-frontal isentropic ascent continues, bands of showers and widely
scattered thunderstorms will spread eastward/northeastward through
the afternoon hours. Convective sustenance has already been noted
across parts of IN. This activity will likely grow in areal coverage
and intensity as weak boundary-layer destabilization occurs eastward
amidst pockets of weak diurnal surface-layer heating. Convective
momentum transport -- augmented by the frontal circulation -- may
support locally strong wind gusts. A few marginally severe wind
gusts cannot be ruled out. Widespread cloud coverage ahead of the
front will limit boundary-layer destabilization, mitigating a more
substantial severe risk.
..Cohen/Kerr.. 01/12/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PBZ...RLX...CLE...ILN...LMK...IND...
LAT...LON 39518578 40368438 41278121 41028013 40348045 39218201
38368505 38538613 39518578SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 12, 4:05 AM EST | Mesoscale Discussion | SPC | Elkhart, Jasper, LaGrange, Lake, LaPorte, Marshall and 4 more | 6 hr |
| Jan 12, 2:22 PM EST | Mesoscale Discussion | SPC | Belmont, Carroll, Coshocton, Fairfield, Fayette, Guernsey and 12 more | 2 hr |
Nearby
Mesoscale Discussions in Ohio, 2017Mesoscale Discussions in Indiana, 2017Mesoscale Discussions in Kentucky, 2017Every mesoscale discussion in 2017
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.