This next system is only going to produce light snow.

1. Very little surface development.

2. Dry air

3. Based on upper level dynamics with a powerful jet streak.

4. First map below.   This is the 250 mb level forecast for just after midnight Tuesday. This is around 32,000 feet above the ground and where commercial jets fly!  Note the powerful jet stream(in knots). Embedded within the jet stream is a 200 mph jet STREAK in red. This is what will cause the snow from the dynamics related to how the horizontal wind speed change aloft, causes divergence at that level, which results in rising(vertical) air motions below it. Rising air is what causes clouds and precipitation.

5. This is the 500 mb level that shows a distinct vorticity maximum aimed right at Evansville. This is the atmosphere's reaction just below the jet speed max. Vorticity is a measurement of spin/lift in the atmosphere. When it increases, we having rising air motions. 

6. Jeff Haby's tutorial on this. He's the best. 

METEOROLOGIST JEFF HABY

https://theweatherprediction.com/habyhints3/748/

https://www.weather.gov/source/zhu/ZHU_Training_Page/Miscellaneous/chart_comparison/chart_comparison.htm

Select a tutorial below or scroll down...   

• Surface Chart    

• 850 MB Chart  

• 700 MB Chart  

• 500 MB Chart  

• 300 MB Chart  

• APPROXIMATE PRESSURE/HEIGHT RELATIONSHIP

++++++++++++++++++++++++++++++++

https://www.weather.gov/source/zhu/ZHU_Training_Page/winds/JetStream_Stuff/300_200_chart.htm

Select A Tutorial Below or Scroll Down   

• Jet Stream Tutorial    

• Jet Streak Movement Tutorial  

• In Depth Jet Streak Tutorial  

• Entrance Region of Jet Streak  

Most people just want to know how much snow is coming and when!

We have that too!

This is the latest forecast from the Evansville NWS, including the numerical forecast broken down into 1 hour time frames:

https://www.weather.gov/pah/

https://forecast.weather.gov/MapClick.php?x=285&y=85&site=pah&zmx=&zmy=&map_x=284&map_y=85

https://forecast.weather.gov/MapClick.php?lat=38.0642&lon=-87.6053&unit=0&lg=english&FcstType=graphical

++++++++++++++++++++

This product predicts 1.0 inch of snow, mainly late Monday evening into very early Tuesday. This is down a tad from the previous model runs. 

That's potentially bad timing for school buses picking up the kids on Tuesday morning. If at least that much falls, slick spots on the country roads and side streets will likely cancel school. Less than that and most of it may melt on the roads and we will be in good shape. 

https://www.weather.gov/media/pah/DssPacket.pdf

The NWS just issued a Winter Weather Advisory for all the counties shaded in purple. This could be expanded  northward when we get closer and confidence in this marginal event is higher.

https://www.weather.gov/pah/

The European Ensemble model does the best at forecasting weather.

This was the last run for predicted snow amounts. That will likely change a bit as we get closer.

This was the last 18z American model. 

There seems to be support for the heaviest snows to be right along and just south of the Ohio River. Even there, the heaviest amounts look to be under 3 inches.