Alert archive / Indiana / Mesoscale Discussions in 2021

Mesoscale Discussion 48

January 30, 202136 counties in Indiana; 16 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jan 30, 2021, 10:39 PM EST for 36 counties in Indiana; 16 counties in Ohio. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jan 30, 2021, 10:39 PM EST (03:39 UTC)
Expired: Jan 31, 2021, 2:45 AM EST
In force: 4 hr
Issued by: the Storm Prediction Center
Concerning: Winter mixed precipitation

All 52 counties

Adams County, IN, Allen County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Delaware County, IN, Elkhart County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jay County, IN, Kosciusko County, IN, LaGrange County, IN, LaPorte County, IN, Madison County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Pulaski County, IN, Randolph County, IN, Saint Joseph County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Union County, IN, Wabash County, IN, Wayne County, IN, Wells County, IN, White County, IN, Whitley County, IN, Allen County, OH, Auglaize County, OH, Champaign County, OH, Clark County, OH, Darke County, OH, Defiance County, OH, Hardin County, OH, Logan County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Paulding County, OH, Preble County, OH, Putnam County, OH, Shelby County, OH, Van Wert County, OH

The radar

The Northern Indiana radar (KIWX), 57 km from the middle of the area, began a volume at 03:45 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 00:00Z, 3.7 hours before the alert went out and 216 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: 1921 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 252 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

103 
ACUS11 KWNS 310339
SWOMCD
SPC MCD 310339 
OHZ000-INZ000-MIZ000-310745-

Mesoscale Discussion 0048
NWS Storm Prediction Center Norman OK
0939 PM CST Sat Jan 30 2021

Areas affected...central and northern IN...west-central and
northwest OH

Concerning...Winter mixed precipitation 

Valid 310339Z - 310745Z

SUMMARY...Heavy snowfall rates will generally range 1 to 1.5 inches
per hour and move from central IN northeastward into northern IN and
northwest OH late this evening into the overnight.  A gradual
transition to mixed precipitation type is forecast across central IN
and west-central OH.

DISCUSSION...Radar mosaic shows a broad precipitation shield from IL
eastward into OH.  Strong low-level warm-air advection/isentropic
lift and ascent associated with mid-level forcing attendant to the
migratory shortwave trough, have resulted in moderate to heavy
snowfall rates across central IN earlier this evening.  The
tropospheric column across much of northern IN has recently
saturated with light to moderate snow being observed as of 1030pm
EST.  Snowfall rates are forecast to increase tonight across
northern IN and northwest OH and peak in the 1 to 1.5 inches/hour
range for a few hours before decreasing.  

Farther south, a nose of warm air around 850 mb was sampled on the
00 UTC Lincoln, IL raob --- indicative of a profile favoring mixed
precipitation atop a sub-freezing layer near the surface.  It
appears this warm air around 850 mb will continue to shift east into
parts of central IN and west-central OH tonight.  Forecast soundings
suggest a transition from snow to snow/sleet or freezing rain/rain
will occur later tonight (12am-3am EST).  It is uncertain how far
north the transition to mixed precipitation type will occur (near a
line from Lafayette-Marion-Celina), but areas farther
south/southwest will be most likely transition to mixed
precipitation type.

..Smith.. 01/31/2021

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

ATTN...WFO...CLE...ILN...IWX...IND...LOT...

LAT...LON   41898652 41908577 40968366 40348353 39798382 39528454
            40108684 40578706 41658688 41898652

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 30, 7:23 PM EST	Mesoscale Discussion	SPC	Jasper, Lake, LaPorte, Newton, Porter, Starke	4 hr

Nearby

Mesoscale Discussions in Indiana, 2021 Mesoscale Discussions in Ohio, 2021 Every 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.