AccuWeather's long-range forecasters say the cold start to spring has delayed the severe storm season, but say atmospheric conditions that have kept the lid on severe weather will soon change.
Most of the severe weather in the Midwest is expected in late spring and early summer.
Otoe County Emergency Management Director Gregg Goebel said the county expects to be as well prepared as ever.
Emergency management tested 11 outdoor warning sirens in Nebraska City and sirens in Dunbar, Syracuse, Douglas and Palmyra on March 27 with no reports of siren failure.
The county has already held its annual storm spotter training and expects to relaunch its Everbridge notification system on April 1.
AccuWeather Lead Long-Range Forecaster Paul Pastelok is forecasting an average ramp-up of severe storm events with damaging wind and hail moving forward.
"The Deep South is going to be under the gun during during April," Kottlowski said.
The actual number of tornadoes is expected to dip this year because of the slow start to the storm season, but forecasters say storm potential will steadily increase through April and May.
According to Severe Weather Expert Henry Margusity, "The blocking pattern responsible for sending cold, dry air masses over the South and Gulf of Mexico should wind down during April."
The pattern has driven the jet stream well to the south, a necessary ingredient for providing energy for severe thunderstorm and tornado development.
During the heart of the severe season, when the threat of tornadoes should be highest, an area to watch will be the lower Mississippi, Ohio and Tennessee valleys. Little Rock, Memphis and Nashville are among the cities that lie in the zone of greatest risk this year.
Overall, the number of tornadoes is expected to be near to slightly below average in 2013.
The 10-year estimated average number of tornadoes to hit the U.S. annually is 1,300. However, the actual annual average is not known due to observing and reporting methods that have changed drastically over time.