The last time Bowling Green, KY had a low temperature below zero (-2) was January 24, 2003. The week of January 21-27 averaged 14 degrees below normal and featured an average high/low of 28/11 (relative to normals of 43/25). The coldest day of that week featured a high of only 14 degrees, a full 30 degrees below normal! The overall synoptic pattern of a southward displaced polar vortex is very similar to what will occur over Super Bowl weekend. In fact, the synoptic pattern is also quite similar to the record breaking cold outbreak of January 18/19 1994, which saw temperatures fall to -11 in Bowling Green and an all-time state-record -37 in Shelbyville. So if the overall synoptic pattern is very similar to these bitterly cold extremes, then why am I not predicting sub-zero low temperatures for Bowling Green?
Simple: Air-mass modification. Both the 2003 and 1994 arctic outbreaks both featured a fresh snowcover over not only the state of Kentucky but also all points northward. The reason 1994 was so cold was that according to the NOAA Great Lakes Ice Atlas, most of Lake Huron and all of Lake Erie were completely ice-covered. Contrast that with the relatively ice-free Great Lakes of 2007 and the lack of snowfall anywhere across the eastern U.S., and it quickly becomes apparent that while the air mass of the upcoming weekend will be synoptically similar to that of years past, the lack of insulating snow cover will allow the air mass to modify as it moves southward from the Arctic into Kentucky.
I do think that the first full-week of February will be the coldest week since January 2003, as the 1000-500mb thickness of 516 dm and 850 mb temps. of -15 for this Super Bowl weekend project to highs in the 20-24 range with lows in the 8-12 range. I won’t be shocked if at least one day during the Sat-Tues period the high doesn’t break 20 degrees. Depending on the amount of snow that occurs from the storm Thursday/Friday, there is the chance that some of the colder spots in northern KY will fall below zero sometime over the weekend.
Right now it appears as if temperatures will moderate some from February 8-15 back to highs in the 30s/40s (similar to last week), but we should remain below normal (45/26) through at least mid-February.
As for the snow chance later this week, I think there is reasonably good consensus on the ensembles (80%) that southern Kentucky will have a plowable snowstorm Thursday. There is also some agreement that lighter amounts of snow will fall over much of KY on late Friday/early Saturday as the leading edge of the truly bitterly cold air enters the area. So for now, here’s…
The Bottom Line
Tuesday and Wednesday: Nothing more than flurries with clouds and sunshine. Highs mid 30s. Lows teens.
Thursday: System will track to our south with overrunning precipitation in TN and southern KY. Should be cold enough for all snow with accumulations of 1-2 inches possible. Variations in the storm track will affect accumulations. High low 30s. Lows mid 20s.
Friday: Clipper system could deliver light snow (coating to 1 inch) late Friday.
Saturday-Tuesday: The coldest air of the winter. Highs 18-28. Lows 5-15. Won’t rule out the possibility that some areas will fall below zero.
2/8-2/15: Moderating but still below normal. Highs 30s/40s. Lows 20s.
Colts by 5