The pre-Easter week has started with a strong upper-atmosphere ridge of high pressure over most of the central U.S. This mild trend has offered some chance for fieldwork in the Midwest, central and Southern Plains and the Delta. However, the pattern goes through a very big change this week and particularly this weekend.
The major change features a notable southward flow of cold air that has been rather bottled up in Canada all winter long. This cold air has only brought a couple of glancing blows over the last several months into the interior U.S., but that will change during the upcoming Easter weekend. A large storm system associated with that colder Canadian air mass will spread moderate to heavy rainfall across most areas east of the Rocky Mountains. Areas that see more thunderstorms, particularly over the far Southern Plains, Delta and Southeast, will be in line for rainfall of one to three inches, and perhaps locally heavier.
tAs mentioned, the real story will be the cold air. Models are lining up to produce cold anomalies of 20o 30 degrees Fahrenheit below normal throughout the Plains states and Midwest from Easter Sunday through at least Wednesday April 15. Models differ about how to handle the next system over the Southern Plains, but the central and Northern Plains through the Midwest look to be in the cold air through at least the remainder of the week, if not into the following week. This puts low temperatures in the 15 to 25 degree Fahrenheit range for much of the Plains and western Midwest from April 12-15 before they start to moderate upward by a few degrees. Temperatures this low for several days in a row could be trouble for winter wheat which is ahead of average in its development in Kansas, with 20% of the wheat in the jointing phase versus an average of 8% jointed in early April.
The pattern will also put a damper on the prospects for fieldwork. The cold will not help to melt snow or drain soils that are soaked from a storm system during the April 3-5 weekend. In addition, a new storm may come out of the Rockies late next week with renewed rain and snow prospects.
In South America, it has been rather dry over Argentina since April 1 and that looks to continue through April 11. The prolonged dryness will be beneficial for mature corn and soybeans. However, it will not be beneficial for double-cropped soybeans that continue in the filling phase through the end of the month. Timely showers look to move back in Easter Sunday into early next week. There may be some stress should the showers not materialize.
In Brazil, showers returned to the dry southern and central areas, but were short-lived and isolated to widely scattered. Damaged corn and soybeans in these areas likely did not benefit from the 25 millimeters (around one inch) of precipitation in the few spots. For the newly planted corn and cotton in central areas, the deficits may be able to be overcome as showers concentrate in the region through April 9, but the prospects of drier weather again this weekend will continue to be a concern.
John Baranick can be reached at firstname.lastname@example.org
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