A flight from Edmonton, Alberta to Puerto Vallarta, Mexico operated by Canadian carrier Sunwing Airlines had to divert to Helena, Montana early this morning due to severe turbulence that injured a flight attendant.
The Helena Independent Record reports that the aircraft experienced "extreme turbulence" after it departed from Edmonton. The injured flight attendant was checked and cleared by medical personnel after landing, "but flight crews were also concerned about the Boeing 737 aircraft itself."
NOAA's Aviation Weather Center shows the potential for "moderate or greater" turbulence across southern Alberta and northern Montana where the incident occurred. A very strong jet stream — seen above with winds between 140 and 160 MPH — over the northern Rockies is likely to blame for the the extreme turbulence the Sunwing flight encountered.