Tennessee Valley Storm Trackers: Another Shot Of Winter Wx on Wednesday

Monday, December 13, 2010

Another Shot Of Winter Wx on Wednesday

Well after the last couple days in the freezer we are looking at another shot of frozen precipitation (freezing rain)during the day on Wednesday.The RPM suggests the main threat will come from about 7:00 a.m. until 2:00 p.m. light rain should begin to fall when surface temps are below freezing. By looking at the model output for Wednesday on the precipitation you might say well if the 540 line is going to be NE of the state so how can we get Ice or freezing rain. It is from what is called overrunning. When a layer of warm, moist air goes up and over the shallow layer of cold air near the surface. As you can see from the model outputs below almost all are in agreement that it is going to be cold enough at the surface. The NAM and GFS has temps between 22F and 26F Wednesday morning. With the deep freeze we have been in the last couple days it will not take much for any freezing rain to cause problems for roads. I want to get this across to all THIS IS NOT LIKE THE ICE STORM SET UP OF 1993. While it might snap a few trees it does not look like it will cause many power outages it is mainly going to be a travel nightmare. This whole thing will turn to all rain by late in the evening on Wednesday as temps warm to the mid to upper 30s. Also prepare for a moderate warm up as well into Thursday as some places could see low to mid 60s (per the GFS outputs)Now lets turn our attention to Christmas even though it is 12 days away. Looking at the model outputs (NOT FORECASTS) it looks to be very cold. The Christmas Eve Output shows it cold enough to have a few snow flurries and then it moves on in the Christmas output, but the cold weather stays. On into the New Years weekend also looks as cold if not colder than Christmas weekend. So lets wait and see if it pans out.

RPM Wednesday