Postdiction

Postdiction involves explanation after the fact.
In skepticism, it is considered an effect of hindsight bias that explains claimed predictions of significant events such as plane crashes and natural disasters. In religious contexts, theologians frequently refer to postdiction using the Latin term "vaticinium ex eventu" (foretelling after the event). Through this term, skeptics postulate that many biblical prophecies (and similar prophecies in other religions) appearing to have come true may have been written after the events supposedly predicted, or that the text or interpretation may have been modified after the event to fit the facts as they occurred.
Skeptics of premonition use these terms in response to claims made by psychics, astrologers and other paranormalists to have predicted an event, when the original prediction was vague, catch-all, or otherwise non-obvious.
Most predictions from such figures as Nostradamus and James Van Praagh express the future with such seemingly deliberate vagueness and ambiguity as to make interpretation nearly impossible before the event, rendering them useless as predictive tools. After the event has occurred, however, the psychics or their supporters shoehorn details into the prediction by using selective thinking—emphasizing the "hits", ignoring the "misses"—in order to lend credence to the prophecy and to give the impression of an accurate "prediction". Inaccurate predictions are omitted.
Supporters of a prediction sometimes contend that the problem lies not with the wording of the prediction, but with the interpretation—an argument sometimes used by supporters of religious texts. This argument may lead to the question: "What is the point of a prediction that cannot be interpreted correctly before the event?" However, the argument is not that the prediction "could not have been" interpreted correctly prior to the event, but simply that "it was not" in the case in question, thus the question is working from a false premise. Of course, any "prediction" that is so vague as to not be correctly interpreted before the event it allegedly "predicted" is functionally equivalent to no prediction at all.
Postdiction in different contexts.
Skepticism.
In skepticism, postdiction is also referred to as post-shadowing, retroactive clairvoyance, or prediction after the fact, and is an effect of hindsight bias that explains claimed predictions of significant events, such as plane crashes and natural disasters. Accusations of postdiction might be applicable if the prediction were:
These types are not exclusive, so a prediction could be vague, statistically likely and open-ended at the same time.
Magic trick.
In a magic trick, postdiction allows the magician to write down an audience member's answer while asking a following question, thus misleading the audience into thinking she is writing down her prediction for the answer to the second question.
Cognitive science.
In cognitive science, postdiction is the justification process that allows a reader to make sense of a concept in a given context. The term was coined by psychologist Walter Kintsch in 1980 and refined by cognitive scientist Afzal Upal in 2005. Heath & Heath used Upal's definition without explicitly citing him in their 2007 book "Made to Stick". Concepts that can be justified in a given context are called postdictable.
Neuroscience.
In neuroscience, postdiction indicates that the brain collects up information after an event before it retrospectively decides what happened at the time of the event (Eagleman and Sejnowski, 2000). Postiction is a particular interpretation of experimental results showing temporal integration of information, and it has been largely debated. 
The duration of the window of temporal integration of sensory information ranges between tens to hundreds of milliseconds. Its duration significantly varies across tasks, so there may be several postdictive windows of integration, and they are consistent across subjects. The duration of the postdictive windows of integration is supposedly hardwired in our brain, but it could be extended by training subjects to systematic delays between causally bounded events. The postdictive window is believed to be triggered by highly salient sensory events acting as "resets", such as abrupt stimuli onset and saccadic eye movements.
Postdiction is argued to play a central role in shaping our sense of agency, by compressing the perceived interval between a voluntary action and its external sensory consequence.
Postdictive mechanisms are believed to constantly underlie our perception, and can be revealed by some perceptual illusions: for example, in the flash lag illusion and the cutaneous rabbit illusion the location of moving stimuli are mistakenly perceived due to their falling within the same postdictive window of integration.