Maryland Weather: Chilly overnight but mostly sunny Saturday

BALTIMORE -- It will be chilly overnight with mostly clear skies. 

Low temps will dip into the upper 20s to around 30 both tonight and again Saturday night. 

Highs will reach the low 40s on Saturday afternoon and upper 30s to around 40 on Sunday. 

Sunshine will continue into next week through Tuesday. Temps will remain in the low 40s for highs with lows in the 20s.

We are keeping a close eye on big changes for the Christmas holiday as a large dip in the jet stream will send Arctic air from Siberia southward into the Lower 48. 

We will see some of the coldest December temperatures in parts of the U.S. in 30-40 years. 

Some of this cold air will spill into the Middle Atlantic by late week, just in time for Christmas. 

There are still some uncertainties as to when the Arctic cold front will arrive, but it appears it will arrive by Friday at the latest. 

There are also indications a coastal low pressure will develop and move up the coast. 

This could bring a potential threat of wintry weather or perhaps rain and wind along with some type of wintry weather just before or on Christmas Eve. 

It is still way too early to speculate or get specific on what could develop, but the pattern favors some type of wintry weather late next week, along with very cold temperatures. 

Keep it tuned to WJZ for the latest updates.