The Wisconsin River headwaters basin snowpack thickened 7-8 inches and accumulated from three quarters to over an inch of water content Feb. 3-4 compliments of a Colorado low that produced the first bona fide snowstorm of the season according to Wisconsin Valley Improvement Company (WVIC), Wausau.

WVIC operates 21 headwater storage reservoirs under license from the Federal Energy Regulatory Commission (FERC) for water conservation and streamflow regulation benefits on the upper half of the 12,000 square mile Wisconsin River basin.

A moist start to February, there was more water in the snow from the one storm than was contained in all of the snow that fell during January.

Upper and central basin snow depths by location in inches Feb. 6 included Lac Vieux Desert 18, Land 'O Lakes 14, St. Germain 13, Rhinelander 10, Tomahawk 10, Wausau 11, Marshfield 10, Stevens Point 12 and Port Edwards 10. Water content over the basin averaged 0.85 of an inch north, and 0.66 of an inch central. The snow at Tomahawk contained 1.05 of an inch of water.

January by its nature is a low-precipitation month with the coldest temperatures. The total at some locations was increased by snow on the 31^st, but monthly average total precipitation was below normal. Over the northern basin, the average total was 0.42 of an inch north, 39 percent of or 0.65 of an inch less that the 1.07 of an inch normal. On the central basin it was 0.46 of an inch, 45 percent of or 0.56 of an inch less than the 1.02 of an inch normal.

The January 30, 2003 Wisconsin River Report stated WVIC was monitoring snowfall because melted snow can provide 20-30 percent of the water for spring refill of reservoirs. That was incorrect. In a normal year, melting snow can provide as much as 50 percent of the water to refill reservoirs.

It will be cold in the Wisconsin River Valley through mid-February according to the National Weather Service. A warm up to the mid-30s and 40 degrees Feb. 1 helped stir the stormy start and produce the moist snow. A Polar vortex has since re-established to the north, and it will be aided by the layer of snow in deepening the cold. The icy grip on the flow of water on the Wisconsin basin will be tighter than it was in January. The low temperature of minus 32 degrees Feb. 7 at Tomahawk surpassed the minus 24 degrees Jan. 28 reported at Eagle River and Rhinelander.

The Weather Service also forecast short wave troughs to develop during the period that would produce additional snow but in lesser amounts than occurred Feb. 3-4.

Wisconsin River weekly average regulated flow was two thirds to 90 percent of normal Jan. 31-Feb. 7. Decreases in natural flow, reductions in flow goals and ice-making cold were factors in the less than normal flow rates.

Flow rates were expected to undergo an additional decrease Feb. 7-13 as sub-zero cold changes more water to ice on the basin.

Most noticeable among the 21 reservoirs as the end of the reservoir year looms are the decreases in water levels in the five large man-made reservoirs. Operated on a daily basis to achieve flow goals, they have larger storage capacities and greater ranges of rise and fall in water level than the 16 natural-lake reservoirs.

Operational levels in the five are approaching winter minimums with five weeks remaining until mid-March and possibly the first stirrings of spring in the valley.

Total reservoir storage was 37.79 percent of capacity Feb. 2.

As it had begun, January ended with above normal temperatures. A surge of warm air from the Pacific Ocean combined with moisture from the Gulf of Mexico Feb. 1 to produce the Feb. 3-4 snowstorm. The outcome was weekly average temperatures Jan. 31-Feb. 6 that were above normal by two degrees at Willow reservoir in Oneida County and 1 degree at Wausau.

Below zero cold was forecast to occur into mid-February.

-End of Report-