In Dimmsdale, if the weather man gets the weather wrong, they get run out of town by an angry mob. So Timmy's mom Mrs. Turner becomes Dimmsdale favorite weather caster after Timmy wishes that whatever she predicts will come true. But when Mom decides to get out of her weathercaster contract, she predicts a series of natural disasters she feels could never happen, not knowing Timmy’s wish will make them come true. Is Dimmsdale doomed? Worse, if Mom can’t get out of her contract and has to work 12 news shifts a day, is Timmy doomed to be raised by a stay at home Dad along with his creepy puppet?
Timmy and his father are watching Chet Ubetcha make a report on Brightburg, a neighboring city of Dimmsdale that has been voted "best place to live" yet again. The two are dressed in fishing gear and are eagerly awaiting the weather report. Chet hands the broadcast off to the weatherman, Stormy Raynes, who predicts that the weather will be sunny enough for fishing. Timmy and his father cheer and run outside into the pouring rain, and are nearly struck by lightning before they realize the weatherman's prediction was wrong. They see Stormy Raynes being chased out of the city by an angry mob holding pitch forks and torches.
The next day, the same thing happens when Timmy and his father listen to a weather report from the new weather reporter, Johnny Downpour. When they run outside, there is a blizzard and Timmy and Mr. Turner are turned into ice cubes. While frozen, they see the new weatherman being chased out of town by the same angry mob. Mr. Turner wants to partake but he has to wait until he thaws out.
Meanwhile, Mrs. Turner has been completely ignored this whole time by her husband and son, who were more concerned with the weather and fishing than her winning the Miss Dimmsdale contest, winning a baking contest, and winning all sorts of awards which Timmy and Mr. Turner completely ignored or destroyed when they were rushing to go fishing. Mrs. Turner decided to enter a contest to become the next weatherman or woman, apparently she was the only one who entered the contest because on the television, Chet Ubetcha reads her name (as "Timmy Turner's mom") off of the very same entry paper she tore off a flier. Timmy and Mr. Turner think only men can tell the weather. Mrs. Turner is excited, but Timmy is worried that his mother will get the weather wrong and chased out of town by an angry mob like the other weathermen.
When she appears on TV for the first time, Mrs. Turner is visibly nervous and clumsily trashes the sound stage by tearing a gaping hole into the weather map and setting off the fire sprinklers. An angry mob begins to form outside the news building.
Realizing his mother is in trouble unless everything she said during her weather report comes true, Timmy wishes that everything his mother predicted about the weather was right. This causes it to become sunny for a brief moment, then a gaping hole appeared in the ground, and then it started to rain again, just like Timmy's mother accidentally predicted. This is enough to convince the mob to disperse, and within days, Mrs. Turner is becoming a well known television celebrity. Mrs. Turner rarely spends time at home anymore, and now Mr. Turner must act as a father AND mother figure to Timmy. He accomplishes this by using a sock-puppet resembling Timmy's mom, much to Timmy's horror and annoyance.
At Channel 7 News, Mrs. Turner is so popular that they only give Chet Ubetcha a few seconds of air time and the remaining twenty nine minutes to the weather, causing Chet to become extremely jealous. Timmy eventually goes to his mom's new workplace and apologizes for how both he and dad have been treating, which Mrs. Turner is very touched and accepts. However, as it turns out, Mrs. Turner can't just quit her new job, as the station made her sign a contract--since the contract itself is pretty much airtight, the only way that Timmy's mom can get out of it is if she were to get fired and/or get run out of town like all the other weathermen/women before her. In the end, Mrs. Turner decides to make a really inaccurate and disastrous weather prediction in an attempt to get fired.
Timmy must find a way to stop her, because no matter what prediction she made, it would come true!
Unfortunately, there is nothing Timmy can do to stop the weather predictions from coming true. Mrs. Turner predicts "hail the size of mini vans", the world's largest lightning storm, and a massive earthquake, and then tomorrow it will be good enough to go fishing. Storm clouds begin to form over Dimmsdale and Timmy realizes he must find another way to stop this wish. He wishes for a giant trampoline to appear over Dimmsdale, this deflects the mini-van sized hail chunks in the direction of Brightburg, destroying it. The giant lightning storm is neutralized by Cosmo while he was asking what to do, and the lightning struck his wand all at once, zapping him and turning him into a pile of ash. But now the earthquake is tearing the ground apart.
Timmy sees his father running with a piece of broccoli suspended in a gelatin mold held by the mom puppet. The puppet then gives Timmy the gelatin. Timmy realizes that the object in the gelatin stays still no matter how much the gelatin itself jiggles. Timmy wishes the entire city was encased in a gelatin mold, which absorbs the shocks of the earthquake and causes the cracks in the earth to divert in the direction of Brightburg, finishing off the neighboring city. Nobody cares however not even Chet Ubetcha who is happy that he is number one on the news again though, Mrs. Turner still got fired because the weather she predicted destroyed Brightburg.
Afterward, Timmy and his mother enjoy a relaxing fishing trip while the angry mob chases Mr. Turner and his puppet of Timmy's Mom (because he refuses to stop using it), much to Cosmo’s joy. The episode ends with Cosmo (once again) getting zapped by lightning.