Definition: Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
Input: Initially very disorganized, surface pressures gradually decreased across the region, with a weak low pressure area developing on September 19.

First very disorganized, surface pressures slowly went down across the area. A weak low pressure area came September 19.