Spring is the main severe season across the continental United States. However, fall, the other transitional month, features another spike in severe outbreaks. Both season can feature sharp contrasts in temperature, deep upper-level troughs, strong cold front, and a jet that dives southward across the lower 48.
Looking at Kentucky's monthly tornado records, you will notice two spikes in confirmed reports. The spring totals stick out first. Then there is another bump, not quite as high, during the fall.
There is a difference in the modes of severe weather during these two seasons. It all comes down to how you make the "recipe" for severe thunderstorms. The ingredients are lift, shear - changes in the wind with speed and direction, and instability - fuel to build tall clouds and develop intense storms. The available amounts of each will determine the threats that thunderstorms will be capable of producing.
Spring storms feature higher amounts of instability and shear. This is why springtime storms carry the potential for all modes of severe weather - damaging winds, hail, and tornadoes. During the fall, instability is not as high but shear stays the same, or could even be greater. Often fall and winter severe storms carry the potential for damaging winds and possible tornadoes.
So it's not completely out of left field that we are tracking the potential for strong storms on Saturday. We have discussed moving the LEX 18 StormTracker Severe Threat Index but for now we are keeping it a "0" with the potential for some storms to producing strong to damaging wind gusts.
A potent cold front will usher in a line of gusty to strong storms Saturday afternoon and evening. Winds may gust up to 45 mph throughout the day tomorrow. Behind the front, it will be turning much colder Sunday with highs in the upper 30s to near 40 degrees.
Looking at Kentucky's monthly tornado records, you will notice two spikes in confirmed reports. The spring totals stick out first. Then there is another bump, not quite as high, during the fall.
There is a difference in the modes of severe weather during these two seasons. It all comes down to how you make the "recipe" for severe thunderstorms. The ingredients are lift, shear - changes in the wind with speed and direction, and instability - fuel to build tall clouds and develop intense storms. The available amounts of each will determine the threats that thunderstorms will be capable of producing.
Spring storms feature higher amounts of instability and shear. This is why springtime storms carry the potential for all modes of severe weather - damaging winds, hail, and tornadoes. During the fall, instability is not as high but shear stays the same, or could even be greater. Often fall and winter severe storms carry the potential for damaging winds and possible tornadoes.
So it's not completely out of left field that we are tracking the potential for strong storms on Saturday. We have discussed moving the LEX 18 StormTracker Severe Threat Index but for now we are keeping it a "0" with the potential for some storms to producing strong to damaging wind gusts.
A potent cold front will usher in a line of gusty to strong storms Saturday afternoon and evening. Winds may gust up to 45 mph throughout the day tomorrow. Behind the front, it will be turning much colder Sunday with highs in the upper 30s to near 40 degrees.
