Well, many of you I'm sure are breathing a sigh of relief after what most of us thought was going to be a significant severe weather outbreak really didn't turn out to be all that bad.  There were a few reports of damage caused by the gusty winds yesterday, as well as some localized flash flooding, and a good number of warnings that were issued for northwest TN, but all-in-all, we didn't see the widespread severe event that we feared.  So what happened??? Why did we put so much hype into this event, and why did it not play out?

First, the reason that we hyped this so much was that all of the forecast models we look at were in agreement on a setup that looked very similar to other recent events that produced severe weather, most recently being the "Super Tuesday" outbreak in February.  All of the ingredients needed for a severe weather outbreak were showing up......warm, moist air at the surface (instability), strong forced lifting ahead of a cold front, and a deep layer of wind shear (turning of winds with height, which is necessary for supercell & tornado development). By Wednesday morning, the Storm Predictions Center had included our region in a moderate risk area for severe weather, with tornadoes being the main threat of concern.  To clarify, a "moderate risk" is an area where severe thunderstorms are expected to be "numerous and widespread". This usually only happens a handful of times each year, and usually is only reserved for situations where the forecasters are very certain of a widespread event.  We were directly in the middle of that target area, so we all felt the need to convey the real threat that we felt existed, based on national forecasts, as well as comparing this setup to those that had produced damaging tornadoes in our area in the recent past.

So what happened then?  Why wasn't this a huge tornado outbreak? Well, basically 2 ingredients failed to show up.  First, a couple of areas of rainfall that moved through the area Thursday morning and afternoon helped to stabilize the atmosphere......basically reducing the amount of "juice" in the atmosphere.  In addition, we never really saw a good break in the cloud cover, as had been expected, and so the sun wasn't allowed to re-energize the lower levels of the atmosphere. Also, a big player in a severe weather outbreak is the jet stream.  Basically, as certain parts of the jet stream move over an area, it causes air at higher levels of the atmosphere to diverge, creating sort of a vacuum above us, which causes air to quickly rise.  For some reason, the jet never made it very far south.  So, to summarize that.....the amount of lift and instability needed for severe storms never materialized yesterday......and the storms weren't able to develop.

One of the most frustrating parts of our job is when the models and forecasts show something coming together, and then Mother Nature decides to change things at the last minute.  Unfortunately, we don't really know when that's going to happen.  The most frustrating part of that happening is that people may think that we are "crying wolf" and are just trying to create a big story or scare people.  The reality is that all of us care about the safety of our viewers.....that's why we do what we do.  We never try to wish for bad weather or hype an event just to scare people. Our goal is to make sure you are prepared for the situation and aware of the potential threat......it's always better to be safe than sorry.  I'm thankful that things played out differently than expected this time around, and hopefully it will be a while before we have to deal with it again.  Try to stay warm this weekend!

Meteorologist Trent Okerson