Contrail, Aviaticus Cloud Viewing Forecast Periodically Updated

Central Wisconsin Flyway Forecast and Summary 5/5/2015

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:

Conditions should be good for aviaticus formation all day tomorrow ahead of Sunday evening's predicted thunderstorms.


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

All Clear on the Central Flyway Today, here is why not a single contrail is to be seen:

Fabulous cool clear blue day with dry upper air and not a spit of an aviaticus trail or hint of a drifting cirrus to be seen.  Where are the aircraft? They can be heard flying over but only with a sharp eye or binoculars can they be spotted today.  They are all laying out sub-visual aerotrails of water vapor, cloud condensing nuclei such as soot.  The cloud mass exited over night and during that time the boundary line passed over the Central Wisconsin Flyway, even if conditions were right for contrail formation not that many flights were scheduled then.

Here are some photos that demonstrate why the aviaticus clouds (contrails) are not forming today:

A wide swath of dry air is covering most of the state of Wisconsin so exhaust vapor is not condensing on the cloud condensing nuclei spewed by the aircraft. Maps of Water Vapor &  Infrared from NOAA Site.

Below is a map of cloud cover with a line drawn to show the approximate corridor of jet traffic

We have a forecast for light rain Friday night 4.24.2015 so the best chance of an aviaticus event would be Friday when a moister boundary line passes through the Flyway from the Northwest prior to overcast.

Update:  Only light non-persistent aviaticus continued through Friday until the overcast covered the view. But as the overcast broke a bit Saturday morning remnants of persistent trails could be seen but no new trails could be seen in the broken cloud cover the rest of the day. 4.25.2015

4/26/2015  0600 CT:  This morning a huge mass of clear day air swung in from the north but it appears a blurred boundary line is following with a bit more moisture so by the time air traffic begins in another hour the transports should sport only short whiffs, if any at all.  The rapid update cycle map does show possible contrail forming conditions in the eastern segment of this flyway but I won't know until the Sunday morning traffic begins if those conditions remain or pushed south and aviaticus actually form.

Note small blue circle within the large white circle near Green Bay on the east side of our east/west Flyway on the Rapid Update Cycle Map:

4/27/2015 1800 CT: The same weather pattern continues. Short to no contrails, none persistent from morning until noon.  Interesting water vapor pattern.  Again the dry area dominated the flyway as moister air pushed in from the east and surface winds were from the north, the dry air (browns and blacks) became faintly stratified with bands of moister air (white) as seen on this map (water vapor site): 

At this time loose bands of natural cirrus clouds were moving through.  By noon a few segments of persistent aviaticus clouds could be seen as aircraft would traverse these areas.  By later afternoon the stratification was gone. Then that air mass had pushed over the flyway as seen in the map with more moister air (white area) replacing it. Infrared Map Site

Some trails became longer but none would persist and a few depending on altitude left short segments as they passed through the cooler moister air:

This photo is looking east from the east/west Flyway. Note a persistent segment of aviaticus clouds.  The natural cirrus may be at or near the same altitude as the aviaticus segment.  These cirrus clouds did not show up on the infrared map but I'm associating these natural and aviaticus cirrus with the bands or lighter areas of moister air.

4/28/2015 0700 CT: It appears by the indicators we should have good aviaticus cloud production by this afternoon. An air mass is moving in from the west-northwest and it appears a distinct boundary line (sheet) will precede this.

http://theorioninitiative2.blogspot.com/2015/04/all-clear-on-central-flyway-today-here.html

It is Time for Professional Meteorologists to Step Up & Begin Forecasting the Big White Elephant in the Sky

Over the last last 4 months I have attempted to forecast contrail events for Central Wisconsin. Untrained in meteorology and particularly in upper atmospheric science, I have had to rely on ground based observations of weather and air traffic patterns and national weather maps and local weather forecasts.  Here are a few things I have learned or observed:

1. All combustion aircraft leave a persistent trail, invisible from the ground, called an aerosol trail, aerotrail for short.
2. The aerotrails are composed of cloud condensation nuclei. (CCN) These are basically small particles of soot that may form into water droplets or ice crystals depending on the temperature of the air.
3. All combustion aircraft add water vapor to the atmosphere.
4. The lengthening or shortening of contrails (cirrus aviaticus) indicates areas of temperature or moisture changes in the upper atmosphere or both.
5. When contrails of short duration begin to lengthen, going to needle size, to pencil, to fishing pole, expect persistent contrails to begin forming. 
6. As drier or warmer upper air masses move into flyway areas expect to see the contrails become shorter in length and duration or not appear altogether.
7. When natural cirrus clouds move through a flyway, contrails will more likely be visible.
8. Multiple persistent trails may spread to form milky sheet clouds. I call these clouds cirrostratus aviaticus.
9. Persistent contrails most likely form on either side of moisture boundary lines, sometimes called dry lines. These boundary lines can be wide and I call them boundary sheets.
10. As the boundary sheets drift within the flyway additional aircraft pass though them laying more invisible aerotrails and moisture making the cirrostratus aviaticus denser in appearance.
11. If the drift is in the direction of the predominant flyway traffic the ice crystal saturation can lead to the viewing of or at least enhance sun dog halos.
12. If  the persistent cirrus aviaticus (contrails) or cirrostratus aviaticus (milky sheets) drift outside the flyway, they tend to thin or dissipate.  With the lack of traffic no more man-made nuclei is added.
13. So far, from identifying the aircraft using flight tracking software,  I have not been able to identity any deliberate laying of chemtrails (chemical trails)
14. All the phenomenon I have observed so far has been from regular commercial airline traffic flying between 30,000-40,000'.

Today we have heavy persistent cirrus aviaticus clouds forming and morphing into cirrostratus aviaticus within the Central Wisconsin Flyway.

http://theorioninitiative2.blogspot.com/2015/04/it-is-time-for-professional.html

Contrail (Aviaticus Clouds) Forecast for Central Wisconsin: Great Day for Photography if You Want to Avoid Man-made Clouds

A wide swath of dry upper air slightly streak with areas of moisture but without any distinct boundary lines will be over the Wisconsin Flyway today.  We should have some hit and miss aviaticus trails tomorrow and Thursday as conditions become a bit more mixed and complex. I'll try to post an update if boundary sheets with moist air become evident.

Update: Wrong! Before noon the dry upper air pushed north and cirrus and sections of cirrostratus moved in from the a southwest front.  Only short trails were seen earlier but as the dry air was replaced small segments of persistent aviaticus clouds (contrails) were scattered about though for the most part trails remained short with quick dissipation. This continued to increase into the afternoon dividing the state into two hemispheres, the dividing line going right over my location. So looking north I would see clear skies, south thicken cirrus of both natural and aviaticus. 

A Boundary line is shown below but again the boundary sheet of moister air reaches further north of the line as this mass inches north so contrails (aviaticus clouds) and longer non-persistent trails formed.  Oddly, the meteorologist were all correct, we had sun all day as the clouds were too thin to block it. How much of the cloudiness was cirrostratus aviaticus is the question.  Natural cirrus were present in the early morning but the continual additions of nuclei to the moving boundary sheets may be the greatest factor. This is why meteorologist need to make contrail forecasts.  Sunny skies do not mean clear blue skies especially along the flight corridors.                                  

                                               Infrared Map: From NOAA Site

Moisture Map, Darker Area indicates Drier Air: From NOAA Site

From the Boundary Line Looking South into the Flyway

http://theorioninitiative2.blogspot.com/2015/04/contrail-aviaticus-clouds-forecast-for.html