Each application has specific amount of memory set aside on the ROM. If an application begins to come close to this limit you will start to see the low memory warning.
To permanently resolve this issue, move apps to the SD Card instead of phone. The key is how to do it without using apps such as Apps2SD which require rooting your Android phone. You do not want to potentially void the warranty on your phone now. Found this detailed article on how to do this.
Been banging my head at it for almost two months now. Finally resolved my issue
Resolve Phone Storage Space is Getting Low on Android Phones