Looking Into Next Week with New DataFebruary 15th, 2013 at 2:47 pm by Chad Evans under Chad's WLFI Weather Blog
Some sleet is possible Monday morning, followed by periodic rainfall through the day Monday. Periodic rainfall is likely Monday night, followed by a rain/snow mixing changing to a very brief period of snowfall Tuesday morning. If there is any accumulation, it looks very minor.
Windy weather will accompany this system with temperatures steady, then rising Sunday night from 29 to 33 & highs Monday near 44. It may stay around 44 up to Monday overnight, then fall to 33 by Tuesday morning. Tuesday may see a high of 33, then fall to around 28 by afternoon.
Shear parameters & surface instability do support severe weather event from Arkansas to Louisiana, Mississippi, Alabama & parts of Tennessee. Some isolated tornadoes of EF0-EF1 strength look likely with scattered wind & hail. However, it does not look optimal for a big outbreak.
Looking at Thursday night-Friday, still looks like all-out blizzard is possible Iowa, Minnesota, Wisconsin, & Michigan to perhaps as far south as northern Illinois. Substantial snowfall accumulations are likely around Chicago. This is supported by most longer-range solutions & I do agree with the GFS’s viewing of this scenario, as it like many more reliable foreign models I like much more. We will watch. Changes are possible in the track, which would increase or decrease our snow &/or icing amounts or when the snow/mix changes over to rainfall.
Here, looks like it may start as snow, but a changeover to sleet & freezing rain southwest to northeast is likely, per current analysis. A changeover to all rain still looks like a good bet over most of, if not, the entire viewing area, before ending as flurries.
Some accumulations of snow & ice are possible before changing to rain as temperatures rise from the 20s to the middle & perhaps upper 30s.
A lot of wind will accompany this storm system with gusts to 35 mph, especially as it exits.
Shear & surface instability parameters support a severe weather outbreak in the southern U.S. with some long-lived & strong tornadoes possible. The best potential of violent tornadoes looks to be Arkansas, Louisiana & Mississippi to southwest Alabama. The severe threat looks to include, however, eastern Oklahoma to Texas, southwest Missouri, Tennessee & eventually parts of western Georgia & the Florida Panhandle. Too much recycled cP (cooler, more stable air) air east of there may limit any severe threat. Some of the severe threat may be shaved on the eastern part of the severe zone if cP is further entrenched into the Piedmont & deep into Georgia & east Alabama.