sunderstorm 

A thunderstorm where the sun stays out the whole time.

Tim: DUDE! It was sunny the whole time it was storming today. There was lightning and everything!

Chase: We live in Virginia, man; we always have sunderstorms.

sunderstorm by Rhetorik April 20, 2009

sunderstorm 

A thunderstorm in which the sun briefly appears in part of the cloud to produce an eerie glow.

We had a sunderstorm that lasted for about half an hour and the mountains in the distance started to look like Mordor.

sunderstorm by pentozali August 10, 2012

Funderstorm 

When you are having so much fun it is out of control.

A brooding thunderstorm of fun.

The party was a funderstorm.
We had a few drinks and before we knew it, a funderstorm was brewing.

Funderstorm by Julian Conaghan October 22, 2010

slunderstorm

A winter storm that includes sleet and or freezing rain, thunder and lightning.

Yesterday's slunderstorm left an inch of ice on the ground.

slunderstorm by Allan K. Mills March 11, 2008

Snunderstorm 

A snow storm and thunderstorm in one. Results in awkwardly timed snow, lightning, and thunder. Usually takes place in bi-polar weather states such as Wisconsin. Most common in the month of spring break.

Why is there a Snunderstorm in the middle of april?

Snunderstorm by snunderstorm May 10, 2011

Dunderstorm 

When it is raining outside, so you decide to spend your entire day inside binge watching The Office.

It's pouring outside, let's have a Dunderstorm in here.

Dunderstorm by Kmoney1795 May 27, 2016

understorm

From LAG.TV, Novawar --

Another term for violently shitting yourself.

Adam: Hey Jeff, that guy had to GG out early. Know why?
Jeff: Why's that, Adam?
Adam: He totally had an understorm. Shit went everywhere. Probably because of that jailhouse c-section.

understorm by shadowdracos January 29, 2015