The upper level jet stream pattern lately has supported near to above normal temperatures across much of South Florida. A pattern called "ridging" where the jet stream buckles northward like a giant hill on the weather map as deflected most of the rain producing storms north of the region (hence why it has been so dry lately) and produced temperatures well above average.
That will be changing by late this week as a significant pattern change occurs with the jet stream. This pattern will consist of a big dip or "trough" in the jet across the eastern US that will send cold air from Canada southward across much of the eastern U.S. including SWFL.
The timing of the cold air is still in question, but it appears that the first effects will be felt in South Florida as early as next Thursday, with the brunt of the coldest air moving into the region Thursday night, Friday into Saturday morning. How cold? Highs barely above 60° Friday afternoon (some areas may stay in the upper 50s) with lows Friday night dropping well into the 40s. Highs on Saturday will reach around 70, so this will be a very brief bout of colder weather. Also it will be windy behind the front with the windiest conditions occuring Friday through Friday night.
We are still several days away from this cold snap and there will likely be some adjustments to the forecast between now and then as far as timing of the front and how cold it will actually get. Either way, plan on significantly colder weather arriving later this week into the first part the weekend (high and low temps 20° - 25°colder than what we've been seeing lately). We'll keep you posted on the cold front as we get closer to its arrival.
Chief Meteorologist Derek Beasley
