Overview
Event Summary
The first significant and widespread snowfall of the 2021-2022 winter season occurred across southeast Michigan on November 27, 2021. Much of the snowfall occurred between 10 AM and 11 PM. Leading up to the event, a Winter Weather Advisory was issued for areas between the I-69 corridor and the Ohio border, where generally 2-4 inches of snowfall was expected to fall. Further north into the Saginaw Valley/Tri-Cities region and the Thumb, snowfall totals were expected to be more in the 1-2 inch range. Actual snowfall totals fell closely within forecasted amounts, with advisory locations seeing the forecasted 2-4 inches of snow. The highest snowfall locations occurred in a swath between the I-96 and I-94 corridors (including Ann Arbor and portions of western and northwestern Metro Detroit), where 3 to a little over 4 inches of snow fell. The first snow of the season resulted in hazardous travel conditions across the region due to reduced visibilites, snow-covered roadways, and slick conditions.
The snowfall occurred as a result of a clipper low pressure system moving southeast across the lower Great Lakes. This system was able to utilize forcing resulting from frontogenetical (FGEN) forcing in the low and midlevels which provided a synoptic source of lift throughout the event. Additionally, mesoscale forcing during the late afternoon and evening hours allowed for enhanced convergence between the I-96 and I-94 corridors, which helped locally enhance snowfall totals closer to the 4 inch range. While not an otherwise unique aspect compared to other snow-producing systems, snowfall occurred approximately 2-3 hours earlier than anticipated as a result of the earlier arrival of the lead edge of the FGEN forcing. More notably, however, was the earlier snow accumulation on area roadways which led to numerous traffic snarls and accidents as drivers readjusted to wintertime driving for the first widespread snow event of the season. One reason for this was the wide surface temperature and dewpoint spread at the onset of the event. Despite road temperatures initially being above freezing at the start of the event, quick saturation in the low-levels of the atmosphere due to falling snow led to rapid evaporational cooling near the surface, which enabled ground surfaces to effectively cool below freezing, thus being capable of accumulating snow vs. remaining wet.
Snowfall Totals
For more detailed snow reports, please see the storm reports tab.
Radar
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Radar loop of the event from Saturday morning through early Saturday night of November 27, 2021. Note: click on image to expand |
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Storm Reports
Below are preliminary storm total snowfall reports from the event.
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1007 AM EST SUN NOV 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0934 PM SNOW ANN ARBOR 42.28N 83.73W
11/27/2021 M4.2 INCH WASHTENAW MI TRAINED SPOTTER
10-HOUR TOTAL
0934 PM SNOW YPSILANTI 42.24N 83.62W
11/27/2021 M4.0 INCH WASHTENAW MI TRAINED SPOTTER
10-HOUR TOTAL
1014 PM SNOW HOWELL 42.61N 83.94W
11/27/2021 M2.7 INCH LIVINGSTON MI NWS EMPLOYEE
10-HOUR SNOW TOTAL
1057 PM SNOW WESTLAND 42.32N 83.38W
11/27/2021 M2.9 INCH WAYNE MI AMATEUR RADIO
11-HOUR SNOW TOTAL
1109 PM SNOW WYANDOTTE 42.21N 83.16W
11/27/2021 M4.0 INCH WAYNE MI TRAINED SPOTTER
12 HOUR SNOW TOTAL
1109 PM SNOW GARDEN CITY 42.33N 83.33W
11/27/2021 M3.3 INCH WAYNE MI TRAINED SPOTTER
12 HOUR SNOW TOTAL
1109 PM SNOW BROWNSTOWN TOWNSHIP 42.15N 83.26W
11/27/2021 M3.5 INCH WAYNE MI TRAINED SPOTTER
10 HOUR SNOW TOTAL
1109 PM SNOW 3 SE YPSILANTI 42.21N 83.59W
11/27/2021 M4.5 INCH WASHTENAW MI TRAINED SPOTTER
10 HOUR SNOW TOTAL
1119 PM SNOW 2 WNW ST. CLAIR SHORES 42.51N 82.93W
11/27/2021 M2.8 INCH MACOMB MI PUBLIC
10 HOUR SNOWFALL TOTAL. SNOWFALL FELL BETWEEN 1 PM AND 11
PM.
1146 PM SNOW WHITE LAKE 42.65N 83.50W
11/27/2021 M3.4 INCH OAKLAND MI OFFICIAL NWS OBS
11 HR TOTAL AT NWS WHITE LAKE WITH 0.28 INCHES LIQUID
EQUIVALENT.
1146 PM SNOW ROMULUS 42.22N 83.37W
11/27/2021 M4.2 INCH WAYNE MI OFFICIAL NWS OBS
11 HR TOTAL AT DETROIT METRO AIRPORT.
1217 AM SNOW FLINT 43.02N 83.69W
11/28/2021 M2.6 INCH GENESEE MI OFFICIAL NWS OBS
11 HOUR TOTAL AT FLINT BISHOP AIRPORT.
1217 AM SNOW SHELBY TOWNSHIP 42.67N 83.03W
11/28/2021 M2.8 INCH MACOMB MI TRAINED SPOTTER
11 HOUR TOTAL.
0101 AM SNOW BERKLEY 42.50N 83.19W
11/28/2021 M3.1 INCH OAKLAND MI PUBLIC
12.5 HOUR SNOWFALL TOTAL. SNOW FELL FROM 1130 AM TO 12 AM
ON THE 27TH.
0630 AM SNOW CASS CITY 43.60N 83.18W
11/28/2021 M1.5 INCH TUSCOLA MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0700 AM SNOW TECUMSEH 42.01N 83.94W
11/28/2021 M3.5 INCH LENAWEE MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0700 AM SNOW LINDEN 42.82N 83.78W
11/28/2021 M2.2 INCH GENESEE MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0700 AM SNOW ADRIAN 41.90N 84.04W
11/28/2021 M2.0 INCH LENAWEE MI CO-OP OBSERVER
11 HOUR SNOWFALL TOTAL. SNOW FELL BETWEEN 12 PM AND 11 PM
ON THE 27TH.
0700 AM SNOW 2 NW WATERFORD 42.68N 83.42W
11/28/2021 M3.0 INCH OAKLAND MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0700 AM SNOW E WHITE LAKE 42.65N 83.50W
11/28/2021 M2.7 INCH OAKLAND MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0700 AM SNOW OWOSSO 43.00N 84.18W
11/28/2021 M2.2 INCH SHIAWASSEE MI CO-OP OBSERVER
13 HOUR SNOWFALL TOTAL. SNOWFALL FELL BETWEEN 10 AM AND
11 PM ON THE 27TH.
0700 AM SNOW 4 N BURTON 43.05N 83.62W
11/28/2021 M1.8 INCH GENESEE MI CO-OP OBSERVER
11 HOUR SNOWFALL TOTAL. SNOWFALL FELL BETWEEN 11 AM AND
10 PM.
0730 AM SNOW GOODRICH 42.92N 83.51W
11/28/2021 M1.7 INCH GENESEE MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0730 AM SNOW LAPEER 43.05N 83.32W
11/28/2021 M1.0 INCH LAPEER MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0730 AM SNOW FARMINGTON 42.46N 83.38W
11/28/2021 M3.3 INCH OAKLAND MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0730 AM SNOW SE ANN ARBOR 42.28N 83.73W
11/28/2021 M4.4 INCH WASHTENAW MI CO-OP OBSERVER
24 HOUR TOTAL SNOWFALL
0745 AM SNOW W ANN ARBOR 42.28N 83.73W
11/28/2021 M3.5 INCH WASHTENAW MI PUBLIC
24 HOUR SNOWFALL TOTAL.
0800 AM SNOW 6 WNW DURAND 42.95N 84.10W
11/28/2021 M3.0 INCH SHIAWASSEE MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0800 AM SNOW 2 S ORTONVILLE 42.82N 83.44W
11/28/2021 M2.3 INCH OAKLAND MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0800 AM SNOW 2 NNW LIVONIA 42.42N 83.39W
11/28/2021 M2.8 INCH WAYNE MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0800 AM SNOW LEXINGTON 43.27N 82.53W
11/28/2021 M1.5 INCH SANILAC MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0800 AM SNOW 3 NE DEARBORN 42.34N 83.17W
11/28/2021 M4.1 INCH WAYNE MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0800 AM SNOW SSE NEW BALTIMORE 42.68N 82.74W
11/28/2021 M1.7 INCH MACOMB MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0816 AM SNOW 4 NNW RICHMOND 42.86N 82.78W
11/28/2021 M3.3 INCH MACOMB MI CO-OP OBSERVER
24 HOUR SNOWFALL TOTAL.
0900 AM SNOW 1 NW DEARBORN HEIGHTS 42.34N 83.29W
11/28/2021 M3.0 INCH WAYNE MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0900 AM SNOW SSE SHELBY TOWNSHIP 42.67N 83.03W
11/28/2021 M2.4 INCH MACOMB MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0900 AM SNOW WNW PLEASANT RIDGE 42.47N 83.14W
11/28/2021 M3.1 INCH OAKLAND MI COCORAHS
24 HOUR SNOWFALL TOTAL.
0930 AM SNOW 5 W LAPEER 43.05N 83.42W
11/28/2021 M2.3 INCH LAPEER MI TRAINED SPOTTER
24 HOUR SNOWFALL TOTAL.
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