flare-up

(noun) a sudden intense happening. Synonyms: outburst, burst. Examples: "An outburst of heavy rain." "A burst of lightning."

(verb) ignite quickly and suddenly, especially after having died down. Synonyms: flare up. Example: "The fire flared up and died down once again."

(verb) erupt or intensify suddenly. Synonyms: erupt, irrupt, flare up, flare, break open, burst out. Examples: "Unrest erupted in the country." "Tempers flared at the meeting." "The crowd irrupted into a burst of patriotism."