upsurge vs spate

upsurge and spate both are nouns.

Word	Noun	Adjective	Verb	Adverb
upsurge	Yes	No	No	No
spate	Yes	No	No	No

As nouns, upsurge and spate are synonyms defined as:

Other synonyms of upsurge include rush, surge.

upsurge (noun)	spate (noun)
a sudden or abrupt strong increase	the occurrence of a water flow resulting from sudden rain or melting snow
a sudden forceful flow	a sudden forceful flow
	(often followed by `of') a large number or amount or extent