NEW ORLEANS - A piece of the polar vortex is expected to break off and plunge south across the United States this week, possibly bringing the coldest air we've seen since March to the Northern Gulf Coast.
The polar vortex is an always present low pressure system that resides at both poles of our planet. It weakens in the summer and strengthens in the winter.
While the vortex as a whole doesn't leave this region, sometimes "chunks" of low pressure can break off and bring unseasonably cold air wherever it ends up going.
That's what's in the forecast this weekend.
A piece of the vortex looks like it will break off and dive deep across the Central and Eastern United States bringing an early taste of winter.
By Sunday morning, folks on the North Shore could be waking up in the middle to upper 30s and folks on the South Shore, including the New Orleans metro area, waking up to near 40 degrees.
Afternoon highs on Sunday will struggle to make it out of the 50s under sunny skies.
Before it gets here, though, expect a fall pattern to continue, with temperatures reaching to near 40 degrees tonight north of the lake and near 50 on the South Shore. Clear skies will continue until the end of the week, with more clouds arriving on Friday.
These clouds are the beginning of our next rain-maker, set to arrive on Saturday.
Off and on showers with afternoon highs on Saturday in the 50s will be the beginning of the brief arctic blast set to arrive Saturday night into Sunday morning.