After more than a week of warmer-than-normal temperatures, the month will end and December will begin on a much cooler note though conditions should remain dry.
Through Saturday, only 5 of the 28 days thus far in November were spent on the cooler side of average. The other 23 were warmer than their daily normal with 9 days being anywhere from 15° to 25° warmer than normal. This November has also failed to see any highs in the 30’s through the 28th. Only one November on record, November 2001, has seen highs in the 40’s or higher for all 30 days of the month. This puts this November on track to be the third warmest on record behind only November 2001 and that of 1931.
Thanksgiving week certainly contributed to this month’s credentials to be one of the warmest in recorded history with highs in Rockford in the middle to upper 40’s through the week and a high of 52° on Saturday. Strong high pressure system to our south brought warm, southerly flow to the area on Saturday providing, with the help of plenty of sunshine, a beautiful start to the weekend. A bit of midlevel moisture advection will cause clouds to build up a bit through Saturday night and into Sunday morning leaving the Stateline with a good mix of clouds and blue sky on Sunday. A cold front will move through the area from the northwest in the early afternoon on Sunday kicking off a big cooldown to begin the new work week on Monday. The timing of the front and added cloud cover should keep temperatures a bit cooler on Sunday though highs in the middle to upper 40’s are likely.
As this front passes over the Stateline, it will bring strong, and cold, northwesterly winds into the area plummeting our temperatures down into the lower 30’s for Monday. This will break our streak of no highs in the 30’s for the month. However, one high in the 30’s through the entire month of November is still a rarity having only occurred three times on record. Monday also kicks off a pattern change in our jet stream which will help to keep conditions cool through the week. Whereas our jet stream has been sitting comfortably to our north for some time, a deep upper level trough will move into the Midwest pulling the jet stream to our south and dragging lots of cold air down into the region from the north. Though flow within the jet stream becomes more zonal through the week, it will remain to our south keeping the cooler air flowing in through the week. Temperatures, however, appear to slowly recover through the week getting back to near seasonable by Wednesday and hopefully back on the warmer side of normal by the weekend.
In the meantime, after a dry November in the Stateline, conditions look to remain dry as we head into December. Through the 28th, Rockford has fallen 0.64” shy of the normal month to date precipitation total of 2.42”. However, if it weren’t for the storm system that brought Rockford the 1.06” of precipitation on the 24th and 25th, the month would be nearly 2 inches shy of average having received measurable precipitation only 4 of the month’s 28 days so far. This dry pattern will continue as we end this month and head into the next. The cold front moving in on Monday will not have a sufficient amount of moisture to provide a decent chance for rain or snow. Following the frontal passage, high pressure will dominate the region at the surface keeping conditions dry and keeping dynamics necessary to produce rain or snow at a minimal. A large trough will do the same in the middle and upper levels of our atmosphere. Through the first weekend of December, there appear to be no reasonable chances for precipitation here in the Stateline at the time of publication. Though a couple of storm systems are forecast to move through the Midwest, they are expected to miss the Stateline to the south and east. Overall, it appears you can expect the first week of December to feel quite a bit like the holiday season, but look like it, not so much.