Volume IV, Issue 1

Severe Weather Climatology for the Four State Region

As the winter season draws to a close, the days become longer, we exit the shelters of our homes to take advantage of the warmer, spring-like conditions we typically see across the four-state region during the months of March through May. Unfortunately, with warmer temperatures and longer days comes the likelihood of strong and damaging thunderstorms which usually accompanies the spring season across the four-state region.

Our region of the county which encompasses Northeast Texas, McCurtain County in Southeast Oklahoma, Southwest Arkansas as well as Northwest and North Central Louisiana typically sees a peak in severe weather during the spring months of March through May. The reasons for this is due primarily to our proximity to the Gulf of Mexico which serves as our moisture source and of course the warmer spring-like days which leads to increased instability. Moisture and instability are the two key ingredients needed for the development of thunderstorms. All that is left in the equation is the need for an upper atmospheric storm system or cold front to help lift this moisture. During the spring months, the storm track across the United States is usually still pretty far south in latitude and this storm track will shift further northward as we exit spring and enter the early summer months.

The graph pictured above shows our peak severe weather season which begins an upward trend in March and peaks in late April and early May before beginning a slow downward trend as we enter the summer months. Total Severe Events include everything from hail producing thunderstorms as well as thunderstorms that produce wind damage and tornadoes.

While severe thunderstorms are possible any time of the day or night during the spring, there is a favored time of the day that is tied to peak heating of the day into the early evening hours, indicated by the graph above. This is due in part to the fact that instability is usually at a maximum from late morning through the early evening hours of the day.

Of particular importance is Monthly Tornado Frequency across the four state region. We see from the graph above, a substantial increase as we transition from March into April and May as we still typically have a southern storm track during these months and the shear necessary for tornadic thunderstorms is enhanced by increased instability during these months.

From the graphs above, it is obvious that we must turn our eyes to the sky during the spring months across the four state region and be wary of what is typically our primary severe weather season. Residents across the four state region are reminded to practice their severe weather preparedness activities, keep a NOAA Weather Radio with you at all times and be ready to take shelter anytime severe weather strikes this upcoming spring severe weather season.