I think that on July 16, 1945, it suddenly got very hot, much hotter than usual, somewhere in the New Mexico desert. However, if the bomb had failed to explode, then there would have been ordinary weather. So, it seems that you need a weather prediction model that …
#1 … has access to information about when and where there will be attempts to detonate bombs, and
#2 … is able to evaluate all of the data to determine whether or not the object will actually explode.
However, if #2 is possible, then there was no need to test the bomb. The explosion in the New Mexico desert on July 16, 1945 was part of a secret, military project. Some civilians heard something and some also saw something. The media received false information from the government to provide a cover story to explain what was otherwise inexplicable.
If one fine day in 1954 you had been at the Bikini Atoll, and suddenly an enormous ball of fire detonated all around you, and melted all of the thermometers in the neighborhood, then wouldn’t you say that the weather had gotten uncomfortably hot?
Link:
en.wikipedia.org/wiki/Nuclear_testing_at_Bikini_Atoll