The fourth season of drug saga “Snowfall” (FX, 10 p.m.) begins with a pair of episodes. By now, it’s 1985 following the reelection of Ronald Reagan and a new war on drugs, including the dealers of South Central Los Angeles.

Dog training is the job of Jas Leverette in the new series “Canine Intervention” (Netflix, streaming).

Antonia Gentry and Brianne Howey play a mother-daughter team who try to escape past troubles by settling down in New England in the new series “Ginny & Georgia” (Netflix, streaming). 

An updated iteration of “HGTV Design Star” comes on the Discovery+ streaming service, but you can also watch “Design Star: Next Gen” (HGTV, 9 p.m.) on cable.  

The final episodes of the Canadian sketch comedy series “Baroness von Sketch Show” (IFC, midnight) begin to roll out. 

Archie, Betty, Veronica and Jughead are now teachers at “Riverdale” (CW, 8 p.m.), so that’s Mr. Jughead to you now. 

“NOVA” (PBS, 9 pm., check local listings) reviews the recent triumphs in the exploration of Mars. 

A surprise visitor introduces “Resident Alien” (Syfy, 10 p.m.) to the institution of marriage.