Summer-Like Pattern for Late May

May 21 2018 9:00 AM CST| 0 Comments | Wisconsin | Long Range Forecast

It was February in April, now it's July in May. This is symptomatic of a very amplified long wave trough pattern.

Upper level ridging has taken over North America this week bringing seasonably warm conditions. This is a mid-summer pattern. The jet stream has shifted north into a position closer to that of July. Troughing on both sides demonstrates the amplified pattern we are dealing with. I predict this ridge will eventually be replaced by a fast paced westerly jet pressing in from the pacific northwest in June and that will be the start or peak of the 2018 storm season.

Wisconsin Weather
Upper level jet displaced north with troughing on the ends.

Wisconsin Weather
Temperatures will rise well above average this week. Much warmer in comparison to last year.

This is unfortunate news for storm chasers you typically plan for storms in the final weeks of May across the great plains. Just bad timing. What goes up most come down and it's only a matter of time. Concern is building that June could be especially stormy for the upper Mississippi Valley and Great Lakes region. Stormier than average, maybe? Don't fall asleep! Our chasers are conserving their energy for whats ahead, poised and ready to roll.

The 7 day forecast showing scattered t-storms for the end of the week. Friday has some potential for severe weather which we will be watching closely. The challenge storm chasing-wise is that while instability will be available, dynamics are weak. T-storms opportunities are dependent on mesoscale features on a short term basis so we will be taking things one day at a time.

Wisconsin Weather
7-Day forecast. 3+ day range has not performed well.

Overstepping Thought

Could this be the new normal as we descend into the solar minimum? The pattern becomes increasingly more amplified as cold air is mixed south disrupting the equilibrium? More amplified = more elaborate and longer lasting weather patterns but also dislocated weather regimes (i.e Feb in April)? We've been observing a trend for the last couple years with flip-flopping weather months. Things to think about.

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