Alert archive / Ohio / Mesoscale Discussions in 2011

Mesoscale Discussion 39

January 20, 201117 counties in Kentucky; 31 counties in Ohio; 5 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jan 20, 2011, 3:36 PM EST for 17 counties in Kentucky; 31 counties in Ohio; 5 counties in West Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jan 20, 2011, 3:36 PM EST (20:36 UTC)
Expired: Jan 20, 2011, 6:30 PM EST
In force: 3 hr
Issued by: the Storm Prediction Center

All 53 counties

Boone County, KY, Bourbon County, KY, Boyd County, KY, Bracken County, KY, Campbell County, KY, Carter County, KY, Fleming County, KY, Gallatin County, KY, Grant County, KY, Greenup County, KY, Harrison County, KY, Kenton County, KY, Lewis County, KY, Mason County, KY, Nicholas County, KY, Pendleton County, KY, Robertson County, KY, Adams County, OH, Athens County, OH, Brown County, OH, Clermont County, OH, Clinton County, OH, Coshocton County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Gallia County, OH, Guernsey County, OH, Hamilton County, OH, Highland County, OH, Hocking County, OH, Jackson County, OH, Lawrence 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, Scioto County, OH, Vinton County, OH, Warren 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), 61 km from the middle of the area, began a volume at 20:37 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, 8.6 hours before the alert went out and 60 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 642 m above ground
0-6 km bulk shear: 85 kt
0-1 km storm-relative helicity: 100 m²/s²
0-3 km storm-relative helicity: 258 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.

309 
ACUS11 KWNS 202036
SWOMCD
SPC MCD 202036 
WVZ000-OHZ000-KYZ000-INZ000-202330-

MESOSCALE DISCUSSION 0039
NWS STORM PREDICTION CENTER NORMAN OK
0236 PM CST THU JAN 20 2011

AREAS AFFECTED...PORTIONS OF THE MIDDLE OHIO VALLEY REGION

CONCERNING...HEAVY SNOW 

VALID 202036Z - 202330Z

BANDS OF MODERATE TO HEAVY SNOW WILL OVERSPREAD PORTIONS OF THE
MIDDLE OHIO VALLEY REGION THROUGH LATE AFTERNOON...WITH RATES UP TO
1 INCH PER HOUR EXPECTED.

LATEST OBSERVATIONS INDICATE THAT A BAND OF MODERATE SNOW IS
DEVELOPING ALONG THE INTERSTATE 71 CORRIDOR FROM CNTRL OHIO INTO
NWRN KY....WITH AREAS OF LIGHTER SNOW ACROSS S-CNTRL OHIO. THIS
ACTIVITY IS BEING DRIVEN BY DEEP-LAYER ASCENT AHEAD OF A TROUGH
SWINGING THROUGH THE GREAT LAKES AND OHIO VALLEY REGION. SNOWFALL
RATES ARE FORECAST TO INCREASE THROUGH THE REMAINDER OF THE
AFTERNOON AS THE STRONG ASCENT PROGRESSES EASTWARD WHILE BEING
AUGMENTED BY INCREASING 700-MB FRONTOGENESIS. FORECAST SOUNDINGS
THROUGH LATE AFTERNOON INDICATE THAT THE ASCENT WILL COINCIDE WITH
RELATIVELY DEEP AND SATURATED DENDRITIC GROWTH ZONES TO PROMOTE
EFFICIENT SNOW GROWTH. ADDITIONALLY...MODEL GUIDANCE SUGGESTS THE
DEVELOPMENT OF WEAK SLANTWISE INSTABILITY BY 00Z ACROSS PORTIONS OF
EASTERN OHIO...WHICH WILL FURTHER SUPPORT MESOSCALE BANDING AS THE
ACTIVITY SHIFTS EASTWARD. AS SUCH...BANDS OF MODERATE TO HEAVY SNOW
ARE FORECAST TO AFFECT THE DISCUSSION AREA THROUGH LATE
AFTERNOON...WITH RATES UP TO ONE INCH PER HOUR EXPECTED.

..COHEN/GARNER.. 01/20/2011

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

ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...

LAT...LON   38698505 39328448 40118315 40488161 39748072 38728152
            38218314 38208425 38698505

Nearby

Mesoscale Discussions in Ohio, 2011 Mesoscale Discussions in Kentucky, 2011 Mesoscale Discussions in West Virginia, 2011 Every mesoscale discussion in 2011

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.