snotgasm
Sudden, spontaneous, copious clearing of a stuffed up nose, often with embarrassing results, especially when it occurs in public with no tissue or other aid nearby. Snotgasms often lead to huge bouts of sneezing. Ironically, many people also experience much sneezing after other sorts of gasms as well.
Emily was just about to read the Old Testament lesson at early service when she had a huge snotgasm and ended up sneezing all over the Bible.