December for the La Crosse HSA had near to above normal precipitation and above normal temperatures.
December 2012 precipitation ranged from near normal in the southwest corner and much of the far north end of the HAS, to above normal across the rest of the HSA. The month was dominated by two strong winter weather systems, but precipitation did fall with weaker systems at other times during the month. December started out warm with weak passing lows and cold fronts bringing patchy light rain to the HSA on the 1st, 3rd and 6th. The first of the stronger wintry systems brought moderate to locally heavy snow to the entire HSA on the 9th into the early hours of the 10th. Another strong but warmer system brought moderate rains to most of the HSA on the 15th. A weak low and disturbance aloft brought light snow to mainly the south half of the HSA on the 18th. The second of the stronger winter storm systems brought moderate to heavy snows to most of the HSA on the 20th. Strong winds accompanied this system, producing near blizzard conditions at times across the central and south parts of the HSA that day. Quieter and colder weather then settled across the Upper Midwest through the Christmas holiday period. A modest strength low and disturbance aloft brought light to moderate snows to the entire HSA late on the 27th and through the 28th. The month ended cold with the first sub-zero lows of the season at many locations on the 31st.
Normal precipitation for December ranges from around 1.25 inches across the northwest end of the HSA, to around 1.75 inches over the far southeast end. Totals for this month ranged from 90 to 110 percent of normal across the southwest corner and much of the far north end of the HSA, to 150 to 175 percent of normal over much of the central and southeast portions of the HSA. Most December totals were 130 to 160 percent of normal. Extreme totals recorded for the month ranged from 1.14 inches at Medford in Taylor Co. WI and 1.16 inches at Charles City in Floyd Co. IA, to 2.42 inches at Steuben in Crawford Co. WI and 2.53 inches at Waukon in Allamakee Co. IA. December snowfall was below normal to much above normal, ranging from 6 to 10 inches over the southwest end of the HSA to 18 to 28 inches over the east and north-central parts of the HSA. A good share of the snowfall during the month was produced by the passing systems on the 9th, 20th and 28th. Normal December snowfall ranges from 10 to 12 inches across the HSA. Snowfall totals this month were mostly 100 to 150 percent of normal.
December 2012 temperatures averaged 24 to 30 degrees. This was 4 to 6 degrees above the normals. Temperatures were above to much above normal on the 1st to the 9th, below normal on the 10th and 11th, then above to much above normal again from the 12th to the 20th. Record highs occurred on the 3rd. The 21st to the 31st saw generally below normal temperatures but for one day of above normal readings on the 28th. Extremes for the month ranged from lows in the single digits above and below zero on several mornings from the 22nd to the 31st, to highs in the upper 50s to middle 60s on the 3rd.
With continued moderate to severe drought across most of the HSA through December, what rain did fall was absorbed by the dry soils. Flows in the rivers and streams of the HSA were below to near normal during December. With the above normal temperatures, ground frost, ice cover on lakes, rivers and streams, and snow cover (even with above normal snow fall), were below normal at the end of the month.