Let's say you have a B-41 nuclear bomb with a yield of 25 megatons.
It ground bursts in the direct center of Madrid, Spain.
A Boeing F/A-18E/F Super Hornet multirole fighter is flying directly away from the bomb (I imagine it doesn't particularly matter which heading/direction) at a steady rate of 280 meters per second overland.
At the instant the bomb detonates, said aircraft is 13.7 kilometers away from the bomb and 5 kilometers above sea level; it is maintaining level flight (i.e. not flying up or down).
What would the thermal and blast effects on the plane be? Assume that it is painted in antiflash white to minimize thermal effects.
When would the blast wave catch up with it?
If said effects are so extreme as to render flight impossible, or so negligible as to not effect the airplane, what is the minimum distance at which this aircraft can survive and continue to fly for several more minutes?
Assume that buildings somehow don't produce a damping shadow.