They broke into her bedroom, she burst into song. The Inappropriate Alto, tonight on Sick, Sad World

Everyone's in a singing kind of mood this day, and there's trouble a' brewin' in the sky. Still, everyone's day starts off normal, except for the songs. Helen and Quinn disregard the weather forecast, which mentions a hurricane.
At school, Jane and Daria find out it's Pep Rally day, so they decide to go off to the roof to hide out. However, they miss out on the big news, as Ms. Li runs in and cancels both the pep rally and the "big game" due to the hurricane warning. Everyone's disappointed, but they all leave. Or almost all, as Brittany and Kevin go off to make out (Brittany is trying to cheer Kevin up). Daria, up on the roof, reads about the hurricane watch in the newspaper, and she and Jane try to leave, only to get accidentally locked on the roof by (and with) Kevin and Brittany.
Helen lets her secretary go home early, and Eric comes in to tell her something (sounds like the start of a love song), but has to leave and says he'll e-mail her. Helen, however, stays at work to wrap a few things up. At the same time, Quinn is with the Fashion Club trying to pick out their disaster-wear. They have to leave because the store is closing, but Quinn tries to stay late to get just the right color. Helen and Quinn end up singing a duet about being perfect.
Jake's driving home and calls ahead, but gets the answering machine. He pretty much blows a fuse and puts the hammer down, racing home and singing his worry.
Helen and Quinn make it home and get ready for the storm, Quinn by making cocoa. When Jake gets back he really panics about Daria, and ends up calling the Lane residence after Quinn suggests it. Trent answers, which leads to some confusion until Helen takes over and orders Trent to come over and stay with them.
Daria, Jane, Brittany and Kevin seek shelter in a little shack on the school's roof. Then they start a song about people being worried about them.
Back at the Morgendorffer residence, Jake gets worried sick, and determines to find Daria and Jane. After a song about being manly, he convinces Trent to go with him, so they head out to the Lexus and drive off.
Up on the roof, the shack is starting to come apart in the wind. They have to abandon shack, but first Kevin has to power-head-butt the door open. Once out, they notice the storm is over, and they sing a song about it. Everyone else in town joins in, of course, wherever they may be, which includes Jake in his car after running into a tree.
Then there's a joyous reunion and the finale.

"So I can go to school and there resume my yawning, and get my sleep in class instead of in my bed." -- Daria ("Daria!")

Jake: Hair all right?
Quinn: Looks kinda fake.
Jake: Great! And now my leave I'll take, it's off to work I go...

Brittany: Oh my god! Look at the Jell-O!
Daria: It's jiggling.
Jane: Worried about the competition?

"There really is a school spirit. Spooky." -- Brittany ("Daria!")

Jamie: Are we all gonna die?
Ms. Li: Not on school property. You're all to go home.

"Get down on your knees and begin to pray, that the town blows away." -- Daria and Jane ("Daria!")

Brittany: She was messing with our minds!
Jane: Why doesn't that add up for me?

Quinn: A shrink would have a field-day with my head.
Helen: If he listened to the sentence I just said.

"What do you mean no-one's home right now? Daria! Quinn! Please get home and answer the damn phone!" -- Jake ("Daria!")

Man: Quit swearing like a drunkard and get right with the law.
Woman: We're a very moral family with a baby on board.
Jake: And I say god, god damn it!

"Now sweetie, there's nothing to worry about. (Door slams) Looters!" -- Helen ("Daria!")

Trent: Hello? No, Daria's not here. You want the Morgendorffers.
Jake: Gah! Aah! I am the Morgendorffers!

"Have you done anything to prepare for this hurricane? Yes, hurricane! Trent, I want you to come over and wait for the girls here, you'll be safer. Then put some on, and get over here now young man! Doesn't anybody in this town wear pants anymore?" -- Helen ("Daria!")

Kevin: But by now they're catching on, that two well-liked kids are gone.
Brittany: And I'll bet that someone's even missing you.

"And I'd say I'm on the roof, with a bimbo and a goof, but I'm due to come back down most any day." -- Jane ("Daria!")

"It's really hard to guess exactly what Quinn's thinking, though my instincts says it's probably 'bout her shoes." -- Daria ("Daria!")

Jake: Agh! I can't take it any more!
Trent: Whoa. No more cocoa for you, man.

Stacy and Tiffany: The big wet rainstorms over, where's Quinn?
Sandi: And do we care?

Wraith's Ramblings:
This was actually a very entertaining episode. There was no character development during the episode, but it was amusing, and the songs worked pretty well.
Also see my Rambling of 10-28-00.