We will be traveling from Lodi, OH, to somewhere just west of Chicago, IL, today. It looks like we will see no break from the clouds this New Year’s Eve.
The National Weather Service (NWS) in Chicago has issued a Hazardous Weather Outlook concerning the rivers that are near flood stage. Otherwise, there is no hazardous weather expected. They predict mostly cloudy skies throughout the day with a low of 18 F this evening.
We haven’t picked out our route entirely, but all of them will pass through mostly cloudy skies. The visible satellite imagery shows the bleak situation to our west.
The infrared satellite imagery shows that there are no thick-topped convective cells in this mess. I did not include this image.
The water vapor satellite imagery shows that we will actually drive through an area that has dry air aloft. It won’t disperse the clouds, but it may limit the precipitation.
I have not included a sounding, as no upper air station is representative of our drive. Detroit shows too much moisture (north of the dry slot), and all of the other stations are far south or far west of any route we would take today.
The surface observations (from the SPC Mesoscale Analysis Map) show the cloudy skies, cold temperatures and high humidity (dewpoint is near the temperature).
The surface pressure map shows no strong pressure gradients across our route. A high pressure system is moving into the area, but the gradients are not steep, so the wind will be light.
Synoptically speaking, the 300 mb NAM chart shows that we will be under a strong jetstreak along the route. There will be high deep-layer shear, mostly due to speed changes.
The 500 mb NAM chart shows some Positive Vorticity Advection (PVA) moving into Chicago this evening. There is plenty of vorticity, though the 500 mb winds blow almost parallel to it.
The 700 mb NAM chart shows no rapidly rising air along our route. I have not included the image in this post.
The 850 mb NAM chart shows what I didn’t want to see- Cold Air Advection (CAA) moving into Chicago this evening.
Overall, I expect a cloudy, cold day today, with little wind or precipitation. It will be about like every time I have passed through Chicago, except for one time over the summer where it was warm and muggy.
Thank you for reading my forecast.
The upper air soundings and mesoscale analysis plots are from the Storm Prediction Center website.
The forecasted upper air soundings are from TwisterData.com.
The surface observation and upper level charts are from Unisys Weather.
The satellite data is from NASA – MSFC