Looking ahead: winter weather returns
Wet soils and potentially longer than normal fieldwork delays are just some of the effects of the upcoming weather as the growing season approaches.
During the past week, a very winter-like weather jet stream pattern has developed across North America. A deep troughing feature anchored across eastern Canada and a cold, arctic-origin air mass is in place across much of the Upper Midwest and Great Lakes regions. An area of low pressure along the leading edge of the cold air mass brought widespread snow and freezing precipitation to much of the state on March 22-23, with more than a foot of new snow reported in sections of northern Lower Michigan. The high pressure center is forecast to slowly move through the region during the next several days, leading to a mostly cold and dry weather forecast. One exception will be near lakeshore sections of the Upper and northeastern Lower Peninsulas, where some lake effect snowfall will be possible Saturday, March 26, and Sunday. Snowfall totals should remain on the light side in most areas, but a few spots may see an inch or two of accumulation.
Elsewhere across Michigan, variably cloudy and dry conditions are a good bet through Monday, March 28. An area of low pressure is expected to form and move across sections of the Ohio Valley Tuesday, and may bring the next chance for precipitation. Snow or mixed frozen precipitation is a possibility with this system across at least the southern sections of the state. Another area of low pressure will bring a chance for more precipitation again by the end of next week. While a slow moderating trend is expected through the middle of next week, temperatures will remain well below climatological normals. Highs are forecast to increase from the low and mid 20’s north to the low and mid 30’s south Saturday and Sunday, to the mid 30’s to mid 40’s by Wednesday. Low temperatures are expected to fall to near 0 across inland areas of the Upper and northern Lower Peninsulas to the low and mid teens south through Monday morning. Lows should warm back into the mid-teens north to the upper 20’s or low 30’s by the middle of next week.
Current medium range outlooks call for a gradual deamplification of the jet stream across North America. The upper air trough currently over eastern Canada is forecast to weaken and move into the North Atlantic and be replaced by a general west to east or zonal flow across the continent. The latest NOAA Climate Prediction Center 6-10 day and 8-14 day outlooks (for March 30-April 3 and April 1-7) both call for cooler and drier than normal weather across Michigan and the Great Lakes region. It is worth noting that forecaster confidence in these outlooks is considered lower than normal due to some disagreement between the forecast models. Normal high and low temperatures during late March range from the low 40’s and mid 20’s across far northern sections of the state, to the low 50’s and mid 30’s across the south. Normal weekly precipitation totals for late March range from less than 0.40” across western sections of Upper Michigan to more than 0.65” across the southern Lower Peninsula.
Further ahead, the Climate Prediction Center outlook for the March through May calls for near normal mean temperatures across all but far northwestern sections of the state, where below normal levels are projected. Precipitation totals are expected to remain in the equal chances category statewide. I personally think normal to above normal precipitation totals are a good bet through at least through April, which would mean wet soils and potentially longer than normal fieldwork delays as the growing season approaches.
At this point, with the current La Nina event projected to dissipate during the next couple of months – there are already signs of this occurring in the equatorial Pacific – there is no real forecast direction on either temperatures or precipitation in Michigan or the Midwest for the upcoming summer (the equal chances scenario).
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