9/25 – The Chief’s “Elevated Rain Chances Ahead” Monday Morning Forecast

The upper level pattern across the country remains complex, with an area of high pressure extending from northern Mexico to the Great Lakes and low pressure systems over the High Plains, southeastern Gulf of Mexico and New England. A decaying complex of t-storms over central LA continues to move southward. The thinking is that the cirrus blow off from that convection, seen on visible satellite, will continue to spread across southeast LA and southern/coastal MS. This should aide in at least limiting storm growth and coverage as the afternoon and evening progresses.

The base of the upper level support for an approaching cold front is the northwest of the region: it will slowly nudge south and eastward tonight into Monday. There’s a decent consensus between models that another t-storms complex will develop tonight in the Central Plains and dive south across LA.

The remainder of the forecast period looks to carry with it continued daily rain chances. The upper low over the High Plain will gradually move southeastward across the upper Mississippi and Ohio River Valleys from Tuesday through Thursday. At same time, the upper low over the eastern Gulf will slowly move westward. Any semblance of ridging aloft will be shifted westward, which puts the area under weakness in the pattern. Areas south of I-10 where moisture content is greatest should see highest rain chances but still probably looking at 30-50% over the northern half of the area. It’s not until late this week into next weekend that rain chances fall off as the upper low to the north shifts east and upper ridge builds across the mid-section of the country.