Sunday Evening Forecast Discussion – 7:35 p.m.
January 13, 2013 Leave a comment
After several days of waiting the cold front is on our doorstep. Quite an impressive temperature gradient along the front too – at one point it was 73 degrees in Columbus, MS and 48 in Tupelo. That cold air should slowly make its way into our northwest counties this evening and plod eastward from there.
Models are now fairly similar in taking the front down to about Auburn-Troy by this time tomorrow afternoon before slowing it down even more and eventually pausing. That slow down and pause, as well as the highly afrontal nature of the boundary keeps Central Alabama right in the middle of the axis of max rain potential over the next several days. Most of the rain won`t be particularly heavy but several rounds of light to moderate rain that each bring a half inch or more can add up over the course of 48 hours. We will have to highly consider a flood watch soon if the rain amounts forecast to occur over the next 12-18 hours verify or are exceeded.
We will also have to closely watch temperature trends in the northwestern few counties tomorrow and tomorrow night. Computer model soundings show a pretty shallow cold air mass associated with the front, topped by a warmer layer. The models are forecasting temps to get perilously close to freezing up around Hamilton and Haleyville Monday afternoon and Monday night. Right now the models suggest that temps will stay just above freezing at the ground and the result will be a cold rain. But a difference of just a degree or two lower could result in a much more significant impact.
Today`s run of the ECMWF, as well as today`s GFS and NAM, now show that shortwave energy digging into the southwest states and northern Mexico will cutoff an upper low that will traverse the southern coastal states on Thursday. The models are having a tough time handling this feature and confidence in the forecast drops considerably between Wednesday and Friday (during the time this upper low is now forecast to approach and move through the area). No need to get too carried away with rain chances. Fortunately, it looks like the air mass will have modified enough by that time so that any precip that comes the end of the week would be in the form of rain.
It is not until next weekend until we can fairly safely say that conditions will be completely dry. After that, we sit and wait and try to figure out which direction the really cold air goes after it drops into the U.S. from Canada.
Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather
WVUA 