Madeley, 70, was co-hosting the ITV breakfast show alongside Ranvir Singh and was about to hand the show over to Tobin, 44, when he realised she had “vanished”.
The meteorologist had “nipped” to the bathroom during a commercial break but did not make it back in time for the ITV hosts to smoothly transition to her weather segment.
Madeley said: “We have a vanishing weather girl. Laura is supposed to be here to do the weather. Echoing silence!”
Singh, 48, gasped and added: “Where is she hiding? She will be here in a minute.”
As Tobin finally arrived on set just seconds later, Madeley exclaimed: “Here she is! Did you lose your sense of timing?”
Tobin has been presenting the weather on GMB since 2014, and presented on the BBC for five years prior - but she recently announced she was taking on a new role.
In July, she announced that she has written her first ever book titled Come Rain or Shine, which she said would teach readers “everything you need to know about the weather”.
Tobin made the big reveal in an Instagram post, in which she said: “I’m so excited because I can finally say – ahhh! – I’ve written a book about my favourite topic: the weather.”
The book will become available to buy in bookstores on 1 October and is currently available for presale. Tobin added: “I’ve loved writing it and can’t wait for you to read it.”
Garraway and co-host Adil Ray had been discussing the big news stories of the day before a commercial break, after which they were scheduled to sit down with Strictly Come Dancing stars Amy Dowden and Carlos Gu.
But when the show came back on the air, viewers saw Ray sitting down opposite Dowden and Gu - with no Garraway in sight.
Ray forged ahead with the programme and began asking the dancers about their forthcoming appearance on Channel 4’s Celebrity Hunted.
He kept the show going on his own for about a minute before a slight commotion was heard off-camera and Dowden said: “Morning!”, with Garraway sliding back into her seat looking sheepish.
Garraway admitted: “I took a little bit too long in the shower and the loo.” Referring to headlines about the hot weather and drought warnings across the country, Ray quipped: “She hasn’t heard about the drought and the short showers. It’s alright, we’re here now.”
“So sorry,” Garraway said, as she tried not to laugh.