Seasonably cool and drier weather developed across the Great Lakes region during late October, allowing a resumption and/or acceleration of fall harvest and fieldwork activities across Michigan. With a persistent troughing pattern in place during much of the latter half of October, temperatures fell to below normal values, slowing grain dry down and soil evaporation rates.
Mean temperatures for October ranged from near normal across far southern sections of the state along the Indiana and Ohio borders to more than 4oF below normal across northwestern sections. A hard freeze with widespread minimum temperatures in the mid-upper 20s effectively ended the growing season in many central and south- ern sections of the state on the 18th.
Precipitation for the month was generally above normal over most of the state except for far eastern sections, the result of the very active storm track through the Midwest region earlier in the month. Totals ranged from less than 2.00” across far eastern sections of the Lower Peninsula to more than 6.00” across western and north- ern sections of Lower Michigan and almost all of Upper Michigan. Heavy rainfall during the early fall across much of the central USA from the southern Great Plains north- eastward to the Great Lakes has led to extended fieldwork delays in many areas.
Not surprisingly, current soil moisture levels across much of this region (reaching into western and northern sections of Michigan) are ranked in the top 10% of highest values for this time of year. The latest Palmer Drought Severity Index map categorizes all of Michigan in abnormally moist categories except for the southeastern Lower Peninsula, which was near normal.
Short and long-term outlooks
Most recent medium-range forecast guidance suggests a fairly typical fall-like jet stream pattern during the next few weeks, with the passage of a number of upper air disturbances, frequent chances for precipitation, and relatively large swings in temperature. Precipitation totals through mid-November are forecast to return to above normal levels. Collectively, these outlooks suggest challenges with remaining harvest activities.
Further ahead, most forecasts continue to call for the development of an El Nino event in the equatorial Pacific. Latest NOAA Climate Prediction Center outlooks for the month of November and for the 3-month November through January period both call for warmer than normal mean temperatures, with no forecast direction on precipitation totals.
Andresen is a professor of Meteorology/Climatology with Michigan State University’s Dept. of Geography, Environment, and Spatial Sciences; MSUE specialist and the state climatologist for Michigan.