Alert archive / Iowa / Mesoscale Discussions in 2021

Mesoscale Discussion 32

January 25, 202161 counties in Iowa; 8 counties in Missouri; 13 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jan 25, 2021, 3:26 PM CST for 61 counties in Iowa; 8 counties in Missouri; 13 counties in Nebraska. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jan 25, 2021, 3:26 PM CST (21:26 UTC)
Expired: Jan 25, 2021, 7:30 PM CST
In force: 4 hr
Issued by: the Storm Prediction Center
Concerning: Heavy snow

All 82 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Buchanan County, IA, Carroll County, IA, Cass County, IA, Cedar County, IA, Clarke County, IA, Clinton County, IA, Crawford County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Des Moines County, IA, Fremont County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Henry County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Monona County, IA, Monroe County, IA, Montgomery County, IA, Muscatine County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Atchison County, MO, Harrison County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Worth County, MO, Burt County, NE, Butler County, NE, Cass County, NE, Dodge County, NE, Douglas County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Sarpy County, NE, Saunders County, NE, Washington County, NE

The radar

The Des Moines radar (KDMX), 45 km from the middle of the area, began a volume at 21:27 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

Omaha, NE (KOAX), launched 12:00Z, 9.4 hours before the alert went out and 182 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: 468 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: 155 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

723 
ACUS11 KWNS 252127
SWOMCD
SPC MCD 252126 
IAZ000-ILZ000-MOZ000-NEZ000-260130-

Mesoscale Discussion 0032
NWS Storm Prediction Center Norman OK
0326 PM CST Mon Jan 25 2021

Areas affected...Southeast NE...Central/Southern IA...Far Northern
MO

Concerning...Heavy snow 

Valid 252126Z - 260130Z

SUMMARY...Moderate to heavy snowfall is expected to persist from
southeast NE across central/southern IA into the evening. Snowfall
rates may occasionally exceed 2"/hr, particularly across far
southeast NE and southern IA.

DISCUSSION...Band of moderate to heavy snow is in place from
southeast NE northeastward across central/southern IA and far
northern MO. Heaviest snow is currently occurring along the southern
NE/IA border, where several sites are reporting +SN and low
visibility.

Expectation is for moderate to heavy snowfall to persist throughout
the region into the evening, with a higher probability of 1-2"/hr
snowfall rates along a corridor from LNK (in southeast NE) to OOA
(in south-central IA). In this corridor, ascent strength and depth
is expected to increase as the shortwave trough moves into the
region.

..Mosier.. 01/25/2021

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

ATTN...WFO...DVN...DMX...EAX...OAX...

LAT...LON   41369735 42069602 42509316 42539142 42069040 40449150
            40099645 41369735

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 25, 10:41 AM CST	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Carroll, Cass and 26 more	6 hr
Jan 25, 4:58 AM CST	Mesoscale Discussion	SPC	Adams, Clay, Fillmore, Franklin, Gage, Hall and 15 more	6 hr

Nearby

Mesoscale Discussions in Iowa, 2021 Mesoscale Discussions in Nebraska, 2021 Mesoscale Discussions in Missouri, 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.