Hot and humid into the weekend with thunderstorms possible

SAN DIEGO (FOX 5/KUSI) -- The region on Friday starting to see cumulus clouds forming over the mountain ridges, an indicator that monsoonal moisture is back which could mean thunderstorms over the weekend. 

While thunderstorm development is favored for the mountains and deserts Friday and Saturday afternoon, beaches and valleys are also on the hook for a slight chance of some activity, especially for Saturday morning between 5 a.m. and 10 a.m. 

The heat dome over the Four Corners region is bringing the hot and humid weather. The clockwise flow around the area of high pressure is digging south into Baja and cycling subtropical moisture in Southern California and the desert Southwest. 

Dew point temperatures at 5 p.m. Friday were in the low to mid 60's for the coastline with mid to upper 50's for the mountains and deserts. Dew point is a great indicator of how much moisture is in the air and what it feels like. Temperatures 61-65 degrees is when the air starts to feel stick or muggy, while 70 degrees or higher is considered tropical. 

It will continue to feel muggy into the evening hours especially the closer you are to the beach, while dew point temperatures will be a bit drier in the low to mid 50's and more comfortable in the overnight hours for mountains and deserts. 

Saturday's daytime highs will be in the upper 70's to low 80's for the coastline, low to mid-90s for the valleys and mountains and around 110 degrees for the deserts. The Heat Advisory is still in effect for the valleys until Saturday evening and same goes for the Extreme Heat Warning for the deserts.

Conditions will cool down and dry out a bit for Monday but another chance of thunderstorms and heat could be on the way for the end of August into the Labor Day Weekend.