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...November Brings Beneficial Rains to Central and Southern Wisconsin...
Periods of rain, showers, and some thunderstorms occurred across central and southern Wisconsin
on the first 4 days of November, 2003. Officially, the greatest rainfall totals of 4.50 to 6 inches
were found in a 20-mile wide band stretching from the Lancaster-Platteville area (Grant County)
northeast through Dane County to Sheboygan County. Here is a statewide listing of accumulated rainfall totals
(6AM Saturday, November 1 to 6AM Wednesday, November 5) across Wisconsin. Other isolated spots in Green,
Rock, and Walworth Counties measured 4.5 to 5.5 inches. Otherwise, the remainder of southern Wisconsin
had 2.5 to 4 inches. Locations in the La Crosse to Stevens Point to Green Bay area came in with 1 to 2 inches.
Unofficially, 9.68 inches fell during the 4-day period at the Lancaster Middle School (Grant County),
a TV-15 Madison WEATHERNET site. In addition, another WEATHNET site in Barneveld (Iowa County)
registered an unofficial 7.85 inches. A UW-Madison professor located 2.5 miles west of Middleton
(Dane Co.) measured an unofficial 6.8 inches. An amateur radio operator near the intersection of
County Highway M and Q, northeast of Middleton measured an unofficial 6.5 inches.
New, official, calendar-day rainfall records were set at the Dane County Regional Airport on November
2nd, 3rd, and 4th (1.41", 1.96", and 1.61", respectively). This is the first time that 3 consecutive
daily rainfall records were set in any month. The first four days in Madison were the wettest 4-day
period ever for the month of November (total of 5.09"). So far, November, 2003, is the 5th wettest
November on record. The wettest November in Madison was in 1934, when 7.86" was measured.
New calendar-day rainfall records were most likely set at many locations from Grant County northeast
to Sheboygan County, especially for November 3rd.
For most of southern Wisconsin the greatest contribution toward the total rainfall for the 4-day
period occurred on Monday into Monday night. However, locations southeast of a line from Port
Washington to Janesville had significant contributions toward the total rainfall Tuesday afternoon
and evening.
Urban flooding was reported during the pre-dawn hours of Tuesday, November 4th in Dane County,
especially in the Madison area. Apparently, tree leaves clogged storm sewers such that water
backed up on city streets. The same thing happened Tuesday afternoon and evening in and around
the cities of Milwaukee and Sheboygan. Water levels in most streams and rivers in southern Wisconsin
increased, and in some cases approached bank-full. Some smaller streams and creeks probably reached
bank-full, or slightly exceeded their banks resulting in very minor low-land flooding.
The basic reason for such rainfall amounts can be attributed to a nearly stationary front that
anchored over northern Illinois during the November 1-4 period. Wisconsin experienced a cool
northeast to north flow of air thanks to high pressure over Lake Superior. Warm and moist air
flowed northeast over the front up and over the cooler air found over Wisconsin. In addition,
a strong jet stream was positioned over the western Great Lakes Region, with wind speeds in
excess of 130 knots (150+ mph) over northern Wisconsin and Upper Michigan. The jet stream
helped generate additional upward motion in the atmosphere over Wisconsin. The result of
these atmospheric interactions was periods of rain, showers, and some thunderstorms as well
low pressure system at the surface moved northeast along the front.
Obviously, the 4-day rainfall put a dent into the drought conditions that have affected much of
Wisconsin in 2003. However, as of November 4th, severe to extreme drought conditions remain
over west-central Wisconsin between La Crosse and the Twin Cities. Moderate drought conditions
remain over southeast, northwest, and central Wisconsin, while abnormally dry conditions prevail
elsewhere across the state.
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