A cold front passed through the region on the evening of the 21st. High pressure to the north allowed for plenty of cold air to move into the region during the nighttime hours of the 21st. A wave of low pressure was moving along the front during this time causing precipitation over the area. Precipitation initially started out as rain before changing over to ice and snow as colder air worked its way in.

Winter Storm in CENTRAL AND EASTERN ALLEGANY, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Unknown

Snow and sleet accumulations were estimated to be around five inches across central and eastern Allegany County.

Winter Storm in WASHINGTON, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snow and sleet accumulated up to 5.8 and 5.0 inches at Hancock and Smithsburg respectively.

Winter Storm in FREDERICK, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snowfall totaled up to 5.0 inches at Thurmont and Walkersville. Snowfall also totaled up to 5.0 inches near New Market.

Winter Storm in CARROLL, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snowfall totaled up to 7.0 inches near Manchester. Six inches of snow was reported at Hampstead and Millers. Five inches of snow fell at Eldersburg.

Winter Storm in NORTHERN BALTIMORE, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snowfall totaled up to 6.3 inches at Parkton and 5.8 inches near Glyndon. Snowfall reports were around five inches across the rest of northern Baltimore County.

Winter Storm in SOUTHERN BALTIMORE, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snowfall totaled up to 5.0 inches at Randallstown and Towson.

Winter Weather in MONTGOMERY, MARYLAND
From 21-FEB-11 20:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snow and sleet totals averaged between one and three inches across the county. A glaze of ice from freezing rain was reported at Four Corners.

Winter Weather in ANNE ARUNDEL, MARYLAND
From 21-FEB-11 20:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snow and sleet totals averaged between one and three inches across the county. A glaze of ice from freezing rain was reported near Parole.

Winter Weather in PRINCE GEORGES, MARYLAND
From 21-FEB-11 20:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snow and sleet totals averaged less than one inch across the county. A glaze of ice from freezing rain was estimated across most of the county.

Winter Weather in HOWARD, MARYLAND
From 21-FEB-11 20:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snow and sleet averaged between two and three inches across the county. Ice accumulation from freezing rain was around one tenth of an inch at Elkridge.

Winter Storm in HARFORD, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snowfall amounts averaged between five and six inches across the county. Snowfall totaled up to 7.0 and 6.8 inches across Bel Air and Norrisville respectively.

Winter Weather in EXTREME WESTERN ALLEGANY, MARYLAND
From 21-FEB-11 18:00:00 to 22-FEB-11 05:00:00 (EST-5)
Reported by: Trained Spotter

Snow and sleet totaled up to four inches at Frostburg and Eckhart Mines.