Precipitation Summary for January 2009

Precipitation totals were recorded daily at our home (Station MI-BN-3) on Crescent Lake near Buchanan, Michigan, following protocols established by CoCoRaHS (the Community Collaborative Rain, Hail, and Snow Network).

Precipitation Summary:

Totals.—Precipitation in the form of rain or snow was recorded on 24 days; measurable amounts of precipitation (i.e., ≥0.01 inches water equivalency) were recorded on 20 (64 percent) of 31 days, with a total accumulation of 2.39 inches (0.08 inches/day, 0.10 inches/day with precipitation, and 0.12 inches/day with measurable precipitation).

Rainfall.—Moisture in the form of rain or a rain/snow mix was recorded on 2 days; measurable precipitation attributed solely to rain was recorded on 1 day with a total accumulation of 0.02 inches (0.0006 inches/day, 0.01 inches/day with rain or a rain/snow mix, 0.02 inches/day with measurable rain or a rain/snow mix).

Snowfall.—Measurable accumulations (i.e., ≥0.1 inches) of snow fell on each of 22 days, totaling 36.2 inches (1.17 inches/day, 1.64 inches/day with snow, and 1.64 inches/day with measurable snow); the water equivalency from new snow was 2.37 inches as measured from a core sample taken from a snowboard (0.066 inches/1.0 inch of snow). The highest 1-day total snowfall was 5.0 inches on the 22nd.

On average, the rain gauge underestimated the water content of new snow by 25 percent (i.e., 1.76 inches of water from snow captured in the rain gauge versus 2.37 inches of water as measured from the snow board, a deficit of 0.61 inches). For this reason, precipitation totals reported above under Precipitation Summary reflect the water content of new snow as measured by a core sample taken from the snow board.

Snow Cover and Snow Depths.—The areal extent of snow cover was 50 percent or more on 29 days, and 100 percent on 27 days. Average snow depth on the 29 days with 50 percent or more snow cover ranged from a trace to 17.0 inches (on the 16th), with a median of 11.5 inches. On days with 50 percent or more snow cover, the amount of water on the ground in the form of snow or ice ranged from 0.03 to 3.09 inches (on the 28th), with a median of 2.18 inches. On average, each inch of snow on the ground (new and old combined) yielded 0.155 inches of water (range 0.06 to 0.24).

Comparisons:

At the official weather station in South Bend, Indiana (located 12 miles SE of this station), the precipitation total for the month (1.57 inches) was 31 percent below the 30-year (1971-2000) norm of 2.27 inches. By contrast, total snowfall (29.4 inches) was 27 percent above the norm of 23.2 inches. Comparable totals for Buchanan this month were 2.39 inches of precipitation and 36.2 inches of snow.

The 30-year (1951-1980) mean December precipitation at Niles, Michigan (located 4.5 miles ENE of this station) is 2.51 inches, while the mean December snowfall for the same period is 17.2 inches.

Temperature, Relative Humidity, and Dew Point (at 7:00 AM):

Temperature.—High (32 on 4th), Median 16, Low (-5 on 16th and 20th). Freezing or sub-freezing temperatures were recorded on 31 days.

Relative Humidity.—High (92 on 3rd), Median 75, Low (59 on 5th).

Dew Point Temperature.—High (27 on 4th), Median 6, Low (-14 on 16th and 20th).