Photos: 17 injured following pileup in dense fog in Southern California

Over a dozen cars were involved in a chain-reaction pileup in Southern California on Wednesday morning amid dense fog.

The southbound lane of the 15 Freeway near Cajon Pass was closed for several hours as crews worked to clear the road of damaged vehicles and debris.

Cajon Pass is located east-northeast of Los Angeles.

At least 17 people were injured in the accident, which occurred just before 11 a.m. PDT, according to the San Bernardino County Fire District. At least two people were transported to a nearby hospital.

"Heavy fog in the area [is] contributing to additional collisions. Extremely low visibility in the area of the incident." the San Bernardino County Fire District said on Twitter.

All lanes were reopened around 1:30 p.m. PDT Wednesday.

fog 1
fog 1

(Photo/San Bernardino County Fire District)

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fog 2

(Photo/San Bernardino County Fire District)

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fog 3

(Photo/San Bernardino County Fire District)

Conditions that caused the fog are not uncommon during May and June in Southern California. The weather pattern is sometimes referred to as "May gray and June gloom."

A light flow of moisture from the Pacific Ocean typically occurs, which creates a stubborn deck of low clouds from coastal waters to the mountains during the late night and morning hours. This low cloud deck tends to break up during the midday and afternoon.

"We expect a quick and major change in weather conditions heading into this weekend," according to AccuWeather Senior Meteorologist Ken Clark.

"The flow of marine air will weaken significantly on Friday and this weekend, and the temperatures will switch from cool to hot in two days in coastal Southern California," Clark said.

Fog should not be a problem over the passes, and low clouds near the coast should break up at a quick pace this weekend.

The marine air pattern may return next week but perhaps not to the extreme of Wednesday and Thursday of this week.