Regional Precipitation Summary for October 2017

October 2017 for the La Crosse Hydrologic Service Area (HSA) saw above to much above normal rainfall, above normal temperatures and near to above normal snowfall.

The above to much above normal rainfall in October produced little more than minor to moderate within bank rises on the rivers and streams of the HSA. Widespread rains of 2 to locally 5 plus inches across much of Minnesota and the northwest half of Wisconsin from the 5th to the 7th produced a strong within bank rise along the Mississippi River through the HSA during the 2nd and 3rd weeks of the month.

Rainfall during this October ranged from above normal across the northwest and southeast ends of the HSA to much above normal across the southwest through central and northeast parts of the HSA. A slow moving low and cold front brought light to moderate rains to most of the HSA from the 1st to the 3rd. Another strong and slow moving low and front brought widespread heavy rains to the entire HSA late on the 5th through the 7th. A round of moderate to locally heavy rains fell across mainly the south half of the HSA on the 10th into the 11th. A passing low brought widespread moderate rains to the HSA on the 13th into the 14th. A cold front produced widespread moderate rains across the HSA on the 21st. The month ended with periods of lighter rain, mainly over the northern and eastern parts of the HSA.

Normal October rainfall ranges from around 2.25 inches over the central third of the HSA, to around 2.50 inches across the northern and southern thirds. Totals in the northwest and southeast ends ranged from 125 to 175 percent of normal, to 200 to 400 percent of normal across much of the southwest through northeast parts of the HSA. Most October rainfall totals ranged from 175 to 300 percent of normal. Extreme totals recorded for the month ranged from 3.30 inches at Wabasha and 3.37 inches at Lake City, both in Wabasha Co. MN, to 8.70 inches at the La Crosse NWS Office in La Crosse Co. WI and 9.91 inches at Mabel in Fillmore Co. MN.

Measurable snowfall for the month was limited to the 27th, on the back side of a stronger passing low. The snowfall was mainly limited to portions of southeast MN and north-central WI. Most October snow totals were near normal to locally much above normal in parts of southeast MN. Normal October snowfall is a few tenths of an inch.

Temperatures for this October ranged from 49 to 54 degrees. This was 1 to 4 degrees above the normals. Temperatures were above to much above normal on the 1st to the 3rd, near to above normal on the 4th to 6th, above normal on the 7th and 8th then slightly above to slightly below normal from the 9th to the 16th. Above and much above normal temperatures returned for the 17th to the 22nd. The 23rd to the 26th saw more near normal readings. The month ended with below and much below normal readings from the 27th to the 31st. Extremes for the month ranged from lows in the upper teens and 20s on the morning of the 31st, to highs in the mid 70s to lower 80s on the 2nd and 8th.

Flows in the rivers and streams of the HSA remained near to above normal during October. The abnormal dryness to moderate drought conditions that had developed over much of the HSA by the end of September were erased by the above and much above normal October rainfall. The wetness of October created additional delays in fall field work and crop harvesting. Harvest activities were up to 2 weeks behind normal in some locations.