Severe Weather Season Update
7/25/2016 1:58 PM
STORM REPORTS – In terms of severe weather Wisconsin is having another down year. There have been 232 total reports: 8 tornado, 35 hail, 189 wind. The majority of severe weather has come from southeast propagating MCS’s/bowing segments producing swaths of damaging winds…like usual. We have observed some weird trends;
Wind = Blue, Hail = Green, Tornado = Red
First, tornadoes have been focused across central Wisconsin this year. They have all been weak, most short lived. This was a trend that we mentioned in our storm season forecast but I still feel it is mostly coincidental. Winter storm tracks were quite consistently through central Wisconsin. Perhaps there is a connection there? We still expect at least one strong/violent tornado in 2016. We continue to believe that August/September could bring an outbreak or two per our analogs.
Funnel cloud in May near Hustisford, WI
Secondly, southwest Wisconsin has remained extremely slow for severe weather. We usually see a couple storm events(May-June especially) where strong storms move northeast out of Iowa into southern Wisconsin. In 2016 these storms have remained along or just south of the state border taking an easterly path merely grazing the state. This puts southern Wisconsin in the outflow/straitform rain/butt-end of severe storms. We’ve began most of our storm chases targeting the WI/IL border only to be pulled south. This gives the illusion of a busted forecast. We are storm chasers. We prepare our own forecasts which we provide for you in our own words. If we don’t forecast things correctly it will be to our own personal detriment as well as yours.
Severe thunderstorm north of Marshfield on June 3, 2016
Third, tornadic thunderstorms have favored northern Illinois for the second year in a row. The majority of which arrived in outbreak style on one afternoon(June 22). If these storms were located just a few miles further north we would be having an entirely different briefing right now. Matter of fact, the better mid-upper level parameters we look at are often better in southern WI. What it was is better than what it could have been(much worse). All I care is that Wisconsinites not become complacent with the expectation this will happen every time because it won’t.
Tornado warned thunderstorm near Waupun on June 4, 2016
BONUS ROUND - the hail reports have been pretty weak in 2016, with exception Mar-May. Hail less than one inch in diameter is common in every year; this year we’ve had a complete lack of significant sized hail greater than two inches. This comes as somewhat of surprise given the increased convective instability we’ve seen. We’ve learned that there is a three-way relationship between thunderstorm hail production processes, updraft organization vs. water loading vs. freezing level. Having one parameters flipped against the rest will limit the hail potential. Upper level’s have been much warmer this year compared to last with a lack of strong northwest flow we’ve seen in recent years. I suspect it will take thunderstorm initiation within the state to temporarily offset the warmer upper level temps, water loading from increased moisture/instability, and produce large hail.
Severe thunderstorm with large hail north of Oshkosh in June
Each year is different. The one thing that never changes are the busts. I’d argue that most setups this year have actually been supportive of severe weather. We’ve had more than one high-profile busts this July through a combination of morning rain, clouds, and lack of parameter cohesiveness (features moving at different speeds, aka timing). Again, busts happen every year. Meteorologists are limited by the chaotic nature of mid-summer weather. It only takes one large thunderstorm to stabilize a thousand square miles or more of atmosphere!
The majority of our severe weather comes in bunches known as outbreaks. I’ve learned that Wisconsin severe weather outbreaks often occur by accident in the sense that it takes something unexpected to happen first. This is why we are always watching and will continue to montior things closely as we move into the final stretch of severe weather season. I’ve always believed that August could be rough this year. Now is not the time to let your guard down. – JP
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