WICHITA, Kan. (KSNW) — Severe weather season is just around the corner. Now is the time for you and your family to prepare for what may be a busier than normal season.
KSN Chief Meteorologist Lisa Teachman says the severe weather season will be delayed. If the right ingredients, including moisture and wind shear, can come into play for the central High Plains, it could be one of the busiest we have seen in years.
The big factor that is setting the stage is La Nina.
This winter we have been influenced by La Nina. Cooler ocean water off the South American Pacific coast has a chain reaction that impacts our weather patterns.
Data shows it has hit its peak and should become more neutral over summer. That said, the effects could linger and enhance our severe storm threat this spring.
Last year we saw a drop in tornado activity, especially near the Wichita area. One reason is the lack of wind shear, or the dangerous twisting of the winds up into the atmosphere, with predominant northerly winds. The other reason is lower dew points.
Research has shown that severe weather is more likely when ocean water is cooler such as in a La Nina phase. These images show tornado and hail frequency during an El Nino year versus a La Nina year.
There is a considerable uptick in activity from Kansas through the Deep South during La Nina.
In January, we saw two tornadoes in California, a deadly tornado in Alabama, and the Wichita National Weather Service issued a tornado warning for several reports of tornadoes six miles south of Coffeyville. Since at least 1986, this weather office has not issued such a warning this early in the year.
For a good chunk of February, Arctic air has surged to the Gulf Coast with record-breaking temperatures in Galveston and other parts of Texas.
Tampa had an EF-0 tornado followed by an EF-2 tornado in Georgia. The tornado threat continued with 3 people dying in North Carolina.
Through March, the main focus for tornadoes will be the Deep South. The jet stream will move north, remain active and the stormy potential will slide to the west, including the Plains.
While this season will start slow, it will turn more active in April and peak in May.
The jet stream needs to shift farther north and the Gulf of Mexico will need to open wide for a decent transport of moisture first.
This year, as every year, we need to be weather aware. What makes this year different is the influence of La Nina and what we have observed during previous severe weather seasons.
There have been similarities made between this year and the La Nina pattern of 2011. That was one of the most active springs in recorded history. It was also the year that produced the Joplin tornado.