As prefaced in my last couple of posts here and here, the first arctic air mass of the season is poised to descend on the Mid-South early next week. The models are also hinting at a possible wet weekend for the WKU homecoming game on November 10.
The arctic air mass expected for early next week can be seen clearly on this map of Monday evening as showers associated with the front move across the Mid-South. There is very little Gulf moisture associated with this front so precipitation should be minimal. Arctic air will overspread KY early Tuesday to the extent that depending on the exact timing of the front, Tuesday could be a day with a midnight high and temperatures steady in the middle-upper 40s throughout the day with wind chills in the 30s. MOS numbers for Tuesday of 50-55 are too high for afternoon temperatures. Teleconnection indices (NAO and EPO)
support the cold shot as well as both the NAO and EPO are currently strongly negative, which supports the idea of a deep trough over the eastern CONUS. The arctic front is also supported by both the European model as well as the GFS ensembles.
Wednesday will be also be cold with highs in the low 50s but Thursday and Friday should have slowly moderating temperatures close to seasonal levels. I am concerned that there could be some warm advection precipitation during Homecoming weekend as depicted here but it is too early to know how much, if any, precipitation will occur as the high departs.
After Saturday, the GFS once again builds a ridge into the Pacific Coast and features a strong jet stream that carves out a trough east of the Rockies. The Thursday 12z run of the GFS produces a monster blizzard for the East Coast for mid-month. As I always like to say, any particular storm shown on the models after day 7 can not be taken literally, but the trend shown by the GFS over days 8-14 along with the teleconnection indices can often be an indicator of mid-range (two week) weather patterns. While the GFS ensembles and the European model for mid-month does show in many cases a polar vortex over the Great Lakes, the EPO is not supportive of an extended cold air outbreak (The PNA and NAO are somewhat in support of the cold pattern). Stay tuned!! If this pattern does verify it could produce the first flurries of the season for the Mid-South