Complex sentence: On October 15, JMA upgraded Megi to a typhoon, and the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) began to mention the typhoon and named it "Juan".
Split into simpler sentences: On October 15, JMA upgraded Megi to a typhoon. Later that day, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) began to mention the typhoon and named it "Juan".