SOUTH MISSISSIPPI (WLOX) - If you've been keeping up with the weather over the past few days, you've probably heard about the upcoming cold snap that WLOX has been forecasting. Though we won't feel the impacts of this front until later in the week, the series of events leading up to this drastic temperature swing have been setting up for over a week now.
Believe it or not, this all got started in the tropics! On November 2, Super Typhoon Nuri became one of the strongest tropical cyclones of the 2014 season as it tracked over the open waters of the western Pacific Ocean. The storm's maximum sustained winds were up to 180 mph, the equivalent of a Category 5 hurricane in the Atlantic. Despite its intensity, it never posed any threat to land. Instead, it re-curved into the cooler waters of the north like many do in the North Atlantic.
The cooler waters weren't enough to stop Nuri, though. Like Hurricane Sandy in October 2012, the tropical cyclone's warm core fused with the jet stream as it continued to track north and east. This transitioned Nuri into an extratropical cyclone with a cold core. With this newly tapped energy provided by the jet stream, it went through a rapid intensification process called “bombogenesis.” This is a meteorological term used when the central pressure of an extratropical cyclone drops at the rate of at least 24 millibars in a 24 hour period.
As the system continued to churn over the Bering Sea this weekend, surface weather observations recorded its minimum atmospheric pressure at 924 mb. This broke the previous record of 925 mb set in 1977 by a similar system near Dutch Harbor, Alaska.
Though the center of circulation itself will not directly impact our region, we'll certainly feel the impacts here in South Mississippi. When Nuri went through the bombogenesis process, it forced the jet stream to become highly amplified. This strengthened the ridge over Alaska, sending a surge of warm, tropical air unusually far north. In turn, the frigid air in the Arctic is being forced southward much earlier in the season.
As a result, temperatures in Alaska are running well above average while the rest of us in the lower 48 watch temperatures drop 20 to 30 degrees cooler than average.
How long will it last? Currently, models are showing that temperatures are going to struggle to rebound over the next couple of weeks. Because of a ripple effect caused by Nuri's rapid intensification, we may see several weaker cold fronts move through before things get better.
Though we won't see sub-zero temperatures or snow here in South Mississippi, our overnight lows will likely drop near or slightly below freezing with the coldest temperatures expected inland. We currently do not expect any records to be broken, but we may come close.
As always, we'll continue to monitor the situation as it continues to unfold. Be sure to stay tuned to WLOX and
for the most up-to-date information on this early season blast of cold air. You can also download our free WLOX 24-7 Weather App for your smart phone to keep up with your forecast while you're out and about.