A cold front will sweep across the region late this weekend and into next week. Throughout much of the fall, most systems have been sweeping through with only about a 2 or 3 hour, or so, period of rainfall. The rain has been confined directly ahead of the front and most of the upper atmosphereic energy has remained well to our north.
This system looks different in several ways.
- The system is quite potent, with upper energy/support forcast to move over the region.
- While intense, short-duration rain is not expected, longer-term soaking rainfall in likely. The following image, using Birmingham, Alabama as an example, shows that there will be a high probability of rainfall for nearly a 12 to 24-hour period. You can also see rainfall accumulates at a modest pace throughout much of this time frame. (source: NOAA/WeatherSpark)
The following image shows the center of upper energy and the direction of movement (red arrow). In the past, the track has been into the Ohio Valley. With this system, it will lift more into the MidAtlantic states. This will provide enhanced lift and transport of moisture into the Southeast U.S.
I took a look at our short-term ensembles. While this data is currently not forecasting any widespread flooding, many rivers within the area of heaviest rainfall are likely to experience strong rises.
Also, expect a significant, and welcome, increases in inflows into Lake Lanier and the Upper Savannah.
I definitely would not be surprised to see some adjustment in the forecast tomorrow as we get a more accurate rainfall estimate. I also would not be surprised to see a small number of forecast points near or slightly exceed flood stage — depending on where the core of heaviest rain falls.
Due to the increase in upper support/energy and slower system movement, this event likely will result in significant water resources recharge for parts of the Southeast U.S. The potential for greatest rainfall, and recharge, will occur across Alabama, Georgia, and the western Carolinas. Here is the latest rainfall forecast.
I hope everyone enjoyed their Thanksgiving Day