The same old song and dance continues across South America. More storms moving through Argentina get into southern Brazil and stall, with periods of showers mostly in the zone between northern Argentina and southern Brazil.
A system moving through over the next few days looks to do the same, but it will come with an extra punch: very cold conditions.
The system itself will not be the driver of cold intrusion. But it will provide ample rainfall to northern Argentina and southern Brazil through June 25. The front will stall across the southern states yet again, and could be pulled southward ahead of a secondary front moving north June 25-28. Rainfall amounts are expected to be in the 25- to 50-millimeter (about 1- to 2-inch) range from southern Parana, Brazil to Corrientes, Argentina.
The secondary front will not have much precipitation with it. Instead, temperatures across Argentina, southern Brazil, and Paraguay will fall well-below normal. This may bring conditions below the freezing mark in portions of Parana, Brazil, the second-largest production state for second-season (safrinha) corn. Parana accounts for roughly 17% of safrinha corn production for Brazil. Corn there is still developing. According to the government of Parana as noted in the latest USDA Weekly Weather and Crop Bulletin, corn is 20% vegetative to reproductive, with the other 80% filling to maturing.
An early frost could put an end to the season for filling corn and have devastating effects for more immature corn should the frost turn to a freeze. Several mornings in a row could see frost conditions, from June 29 to July 2. Temperatures are currently forecast to only get down to minus 1 C or maybe minus 2 C Celsius (28 to 32 Fahrenheit). If temperatures go lower than that for more than just a brief moment before sunrise, significant damage may occur.
Temperatures will not be as harsh on developing winter wheat across either southern Brazil or Argentina. A few hours below freezing is not as much of a hindrance to developing wheat as it is to reproductive or filling corn. Development will slow down, however.
For a country that has seen incredibly terrible conditions for growing safrinha corn this year, a frost across the south would just be another nail in the coffin. Production estimates continue to trend lower on every issuance, but what will the bottom be? Brazil appears to be trying to find it this season.
John Baranick can be reached at firstname.lastname@example.org
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