Fall officially begins today, Sept. 22, and the hot weather that has swamped the first few weeks of the semester seems to be in the rear view mirror.
However, a frigid winter may be ahead.
So far in August and September there have been 26 days in which the temperature was 90 degrees or higher, according to the Lincoln Weather and Climate website. Normally, the two months combined would warrant about 16 days of temperatures greater than 90 degrees, according to the website.
Mark Anderson, a University of Nebraska-Lincoln professor of earth and atmospheric sciences, said that part of the warm temperatures is due to the lack of cloud cover.
“Right now, the reason it’s so much warmer for the most part has been that we don’t have cloud cover,” he said. “When we get the cloud cover our temperatures are 10, 15 degrees cooler because we’re not getting that solar radiation down to the surface.”
A low pressure system is needed for cloud covers to form. But for the last month or so, a high pressure system has been over the region preventing those covers from forming, Anderson said.
Martha Shulski, the director of the Nebraska State Climate Office, said Nebraska is extremely dry at the moment, which is affecting the weather.
In Nebraska, 54% of the state is considered abnormally dry and a moderate to extreme drought covers about 38% of the state, Shulski said.
“That kind of is the influence of the warmness and dryness, overall, that we have experienced in Nebraska,” she said.
These warmer and drier weather conditions are a sign of longer term climate change, according to Shulski. Nebraska and much of the central United States is projected to be warmer and drier in the future than it is now.
For immediate future seasons, Shulski said the Climate Prediction Center is looking at a “La Niña” pattern. This pattern occurs in the equatorial pacific where there are cool waters off the coast of South America and it changes the upper air patterns, Shulski said.
This means it could bring a few different types of weather to the state. Shulski said Nebraska sort of sits on a dividing line where it tends to be colder and wetter to the north but warmer and drier to the south.
There isn’t a very strong sign for what will happen for the state right now, so it depends on some other factors going on in the atmosphere, Shulski said.
Shulski said the climate office will continue to monitor the strength of the La Niña to see whether the conditions from the north will be brought down or if the current pattern of warmer and dry weather will remain.
It is possible there could be some very cold conditions like the state experienced in February.
“That would be another thing I know that I’ll be on the lookout for, just that potential for the arctic air outbreaks in late winter,” Shulski said.
In looking at the seasonal outlooks, it is important to stay up to date on the models because they continue to get updated, she said, so conditions and outlooks can change.
“This can be revisited as the models are run, and as we get closer to the winter the model runs do change,” Shulski said.