Keeping a Watch for Severe Weather...

As we may have already heard from our weather heroes, an increasing chance for severe storms exists for Monday/night. Personally, I'm awaiting additional data before I start becoming too concerned. However, there is the potential for severe weather, including tornadoes.

There are so many scenarios that could unfold, either to support or not support a severe weather outbreak.
Despite some of the obvious parameters that help us identify the likelihood of strong/severe storms, I'm paying special attention to the low-level jet strength.

What is this low-level jet? Well, there are two types: nocturnal and cyclone-induced. In this case, I'm talking about the cyclone-induced low level jet. It is a fast moving ribbon of air in the low levels of the atmosphere, generally around the 850 mB level, or about 5,000 feet high.

Here are a couple of questions to ponder:
What causes the high wind speeds within a cyclone-induced low-level jet?
A strong pressure gradient force originating from the developing mid-latitude cyclone causes the high wind. The strong pressure gradient force is caused by a large temperature gradient between the cold air behind the cold front and warm air ahead of the cold front.

Why is the low-level jet important to severe storm development?
Transports moisture and WAA (inflow) into a developing thunderstorm's updraft. The high-speed wind and directional shear helps generate large values of helicity that can lead to tornadogenesis.

Therefore, as we progress through the weekend, pay attention to any buzzwords like low-level jet and wind speeds at the 850 mB level exceeding 70 knots. This could be a significant indicator for impending severe weather.

Thanks for the info from http://www.theweatherprediction.com/severe/llj/
We'll look at additional severe weather parameters throughout the weekend. Keep checking back.
Have a good Friday evening.
MS