After Weekend Cold, Look for Extended Warmer Temps
Current numerical weather models continue to point toward the possibility of light scattered frost across central, north central, and northeast Nebraska Saturday morning. Areas susceptible to cold air drainage are most likely to see light frost. Areas north and east of Nebraska may experience enough clearing for air temperatures to drop into the lower 30s and upper 20s over a widespread area.
Crop canopies may retain enough heat to offset the likelihood of freezing temperatures penetrating deep into the canopy, affecting crop yields. After Saturday morning, current weather models do not indicate a return to freezing temperatures through the end of September. The primary driver for this forecast is that the western U.S. upper air ridge is projected to build eastward and block polar air from moving southward out of northern Canada.
Weather models hint at the possibility of a weak wave moving southward on the front side of the eastward-building upper air ridge Sept. 14-15. This would primarily impact the eastern third of the state with light precipitation. Another, more potent energy wave is projected to eject out of the central/northern Rockies Sept. 18-20, causing moderate to heavy rainfall from the Dakotas southward through Nebraska and Iowa.
The upper air ridge is then projected to build across most of the continental U.S. during the remainder of the month and confine precipitation to the eastern and western coastal regions. According to the models, high temperatures the final 10 days of the month should consistently be in the mid 70s to mid 80s, which will easily offset the below normal temperatures that have dominated the first 10 days of September.
Thus, barring a hard freeze this weekend, conditions should be favorable to bring the soybean crop to maturity before the next opportunity for freezing temperatures. However, based on the current growth stage of replanted corn, the best estimate is the crop will not be safe from freezing temperatures until the second week of October if normal temperatures are received through physiological maturity.