Quantifying what had become apparent each month, Wisconsin Valley Improvement Company (WVIC), Wausau, reported March 6 that upper and central Wisconsin River basin precipitation during the 2002-2003 calendar winter of December, January and February, was half of normal, and that the snow that fell, with mixed fortunes for winter-related interests, lasted because it was a colder winter than the previous two.

WVIC is licensed by the Federal Energy Regulatory Commission to operate 21 headwater storage reservoirs to regulate a uniform flow in the Wisconsin River.

WVIC found that the average total for nine upper basin locations, from the Wisconsin's Lac Vieux Desert source to Tomahawk, was 1.79 of an inch, 55 percent of or 1.44 of an inch below the 3.23 inches normal for the three-month period. The average total for four central basin locations - Wausau to Wisconsin Rapids - was 1.63 of an inch, 51 percent of or 1.55 of an inch less than the 3.18 inches normal.

Only two locations reported more than two inches of precipitation. Lac Vieux Desert, lake effect snow stealing moisture from Lake Superior to produce it, reported 2.14 inches, and Wausau, where rain fell in a Feb. 3-4 snowstorm, reported 2.07 inches. Driest locations were Little St. Germain, 1.41 of an inch, and Wisconsin Rapids, 1.30 of an inch.

From WVIC's historic snow survey reports, normal upper basin snow depth would be 11 inches with 2.87 inches of water content as March begins. Snow depths reported to the National Weather Service (NWS) March 6 ranged from 11 inches at Land 'O Lakes to nine inches at Rhinelander and 8 inches at Wausau. The water content was 62 percent of normal.

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It was a low-precipitation, cold winter because the warming of the Pacific Ocean called El Nino influenced the course flown by high altitude winds to steer storms away from the Wisconsin Valley and let cold from the Arctic flow in.

The shortest month rivaled January for coldest temperature honors, but unlike its dry predecessor, February was near normal for precipitation thanks to a month-opening storm, the only bona fide snowstorm of the winter so far. Average total precipitation was 0.88 of an inch north, 97 percent of or 0.03 of an inch less than the 0.91 of an inch normal. Average total precipitation was also 0.88 of an inch central, 94 percent of or 0.06 of an inch less than the 0.94 of an inch normal.

Wisconsin basin normal March average weekly temperatures are 25 degrees north and 29 degrees central. High temperatures March 1 neared 40 degrees over the basin. But true to trend, low temperatures March 6 dropped to minus 23 degrees at Willow reservoir in Oneida County and minus 9 degrees at Wausau. The month may have come in like a lamb, storm-wise, but it shivered under its wool.

NWS forecasters predict cold temperatures to continue through March 12 with snow falling March 8 and a rise in temperatures by March 15.

Until temperatures generate melting and runoff to its tributaries and mainstem, the Wisconsin River will flow at naturally low winter rates. March long-term normal flows along the river, averages that are inflated by the occurrence of early spring flood flows, stood in stark contrast to the river's current somnambulant pace the first week of the month.

Weekly average regulated flows were running at from 40 to 72 percent of normal.

Should temperatures by March 15 climb into the 40s as forecast, the first stirrings of spring breakup may occur in the lower portion of the 12,000 square mile basin. In anticipation of conserving the water melting will produce, storage capacity March 2 in WVIC's 21 reservoirs was 75 percent. Earlier this winter, based on precipitation trends, WVIC forecast it would carry over some 20 percent of the water in storage as a conservation hedge for spring refill. Total reservoir storage was 24.82 percent of capacity March 2.

As the current El Nino weakens, the NWS Climate Prediction Center has forecast a return to near normal conditions over the United States April through October. In a February 20 forecast, the Center had mapped drought conditions expanding in the Midwest (see map that follows).

-End of Report-