The Central Wisconsin Flyway is right on the edge of a boundary line (sheet) with heavy clouds to the South and dry clear skies to the North so we should see some aviaticus (contrail) formations today unless the dryer air pushes south over the Flyway. The Rapid Update Cycle Map is showing conditions for contrail formations favorable to the south, but it appears the cloud cover is too heavy to matter.
Central Wisconsin Flyway Forecast and Summary 5/2/2015
I was out of town most of day so it was interesting to view another flight pattern producing mostly non-persistent aviaticus and a few lasting segments in a double-layered clouded sky, cumulus and light upper scattered sheets.
Back home toward dusk only whiffs were being laid and in this short video they can not be seen:
At the time of the video dry air was passing over the Flyway from the west shown as the dark swath on the moisture map:
Central Wisconsin Flyway Summary and Forecast 5/1/2015: Yesterday began with a full morning of no trails, not a whiff or a pencil. Just a sun-filled sky dotted with the summer-like white cumulus. Then about 1 PM CT with some moister upper air, short non-persistent spits were forming from the afternoon east bound. The aviaticus trails grew longer as the afternoon progressed indicating a boundary sheet was entering our Flyway preceding a thicker cloud bank. By dusk persistent aviaticus continued forming and in the far west horizon a layer of white clouds could be seen creeping in. In the morning thin sheets of upper clouds were still present and the Flyway was still marked with lateral aviaticus clouds holding together for example 15 minutes before dissipating, and heavier, broken patches of high natural clouds followed. The natural cloud bank may continue to thicken to where aviaticus will not be viewed this afternoon and it appears this bank will pass over and the trailing edge may be a boundary sheet where trails will form until dryer air follows this.
At 1:10 PM CT yesterday the airliners started to leave short trails, here is a video of 4 flights that passed overhead 37,000-40,000'. Video at 24X speed (Please excuse the poor quality of this clip, I'm just starting to work with a screen recorder):
By 6:30 PM CT Skies had many persistent segments in the boundary sheet as a cloud layer approaches:
http://theorioninitiative2.blogspot.com/2015/04/forecasting-day-long-aviaticus-cloud.html
