Alert archive / Ohio / Mesoscale Discussions in 2021

Mesoscale Discussion 66

February 9, 2021Boone County, Campbell County, Kenton County, Kentucky; 5 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Feb 9, 2021, 12:18 AM EST for Boone County, Campbell County, Kenton County, Kentucky; 5 counties in Ohio. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Feb 9, 2021, 12:18 AM EST (05:18 UTC)
Expired
Feb 9, 2021, 2:15 AM EST
In force
117 min
Issued by
the Storm Prediction Center
Concerning
Heavy snow

Counties Boone County, KY, Campbell County, KY, Kenton County, KY, Brown County, OH, Clermont County, OH, Highland County, OH, Pike County, OH, Ross County, OH

The radar

The Cincinnati radar (KILN), 45 km from the middle of the area, began a volume at 05:18 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 00:00Z, 5.3 hours before the alert went out and 46 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-pSkew-T log-p diagram, Cncnati-Daytn, OH at 00:00Z on 2021-02-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Cncnati-Daytn, OH at 00:00Z on 2021-02-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 257 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
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
1272 m above ground
0-6 km bulk shear
84 kt
0-1 km storm-relative helicity
257 m²/s²
0-3 km storm-relative helicity
475 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

140 
ACUS11 KWNS 090519
SWOMCD
SPC MCD 090518 
OHZ000-KYZ000-INZ000-090715-

Mesoscale Discussion 0066
NWS Storm Prediction Center Norman OK
1118 PM CST Mon Feb 08 2021

Areas affected...Southwest OH and far northern KY

Concerning...Heavy snow 

Valid 090518Z - 090715Z

SUMMARY...An intense snowfall band with rates of 1-3 in/hr that has
impacted the greater Cincinnati Metro Area may remain
quasi-stationary over the next couple hours before finally
diminishing after about 07Z.

DISCUSSION...While 21Z SREF and 00Z NAM guidance finally picked up
on low probability potential for snowfall rates to exceed 1 in/hr
(while other guidance remain subdued), snow rate efficiency has
exceeded expectations within a mesoscale band of heavy snow that
continues to impact the greater Cincinnati Metro area through
southwest OH. Latest storm reports and observations confirm that 1-3
in/hr snowfall rates have been common. Forcing for ascent within and
below the dendritic growth zone that is centered near 600 mb is
consistently progged to subside during the next few hours across
this region. However, given the nearly steady-state nature of this
snow band without appreciable eastward advection, it seems plausible
that snowfall rates exceeding 1 in/hr should persist through about
07Z before eventually diminishing.

..Grams.. 02/09/2021

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   38908494 39108436 39388341 39428288 39368269 39168275
            38998317 38828401 38788460 38768496 38868504 38908494

Nearby

Mesoscale Discussions in Ohio, 2021Mesoscale Discussions in Kentucky, 2021Every mesoscale discussion in 2021

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.