This post is a little late in the day for a true forecast, but I’ll tell you what is happening. Currently, the skies over Charlottesville, VA, are overcast and a light rain is falling. It has been humid all morning and the winds are still. While writing this post, I heard the first crack of thunder. Here is a photo of the sky from part of the UVA campus, just before the rain began.
The visible satellite imagery shows partly cloudy to overcast skies for much of Virginia. You can see one large cumulus cell near Charlottesville, which is the culprit producing this rain.
The infrared satellite imagery shows that the blobby cell here has cooler, higher tops than the clouds throughout most of the state. In Northern Virginia, they also have some higher, cooler-topped clouds, and are likely receiving precipitation as well.
The water vapor satellite imagery shows a large shortwave ridge approaching from the west. This ridge will bring humid air from the Gulf of Mexico. Currently, we are at the transition of this ridge, or the back end of the previous trough, whichever way you would like to think of it.
I am going to skip the 12Z sounding, as that is quite old at this point.
The base reflectivity radar image from Blacksburg, VA, shows that these storms are forming near the mountains, but then moving off the mountains once they become tall enough to be influenced by the upper level winds. Upslope flow provides some of the lift, and is then intensified by the upper level dynamics. A few cells are starting to show small hail.
We will drive back to King George County from Charlottesville in a few minutes, and likely have these storms on our heels for most of the drive.
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