The links below include current weather, space weather, Magnetic Field study, and how these can affect the pigeon's homing ability.
Current Weather, TheWeatherNetwork.com
Pigeon Homing: Observations, Experiments, and Confusions
Author: Dr Charles Walott
NASA studies the earth's inconstant Magnetic Field
Bird's can 'see' Earth's Magnetic Field
Stanford Solar Center asks "How do pigeons navigate?" - Where can pigeon racers get solar activity data?
PigeonNavigation.com studies Solar Storm criteria that can affect pigeon navigation, and alerting pigeon fanciers world-wide to conditions that may result in the loss of their birds.
Confused Homing Pigeons and Space Weather
Geomagnetic Activity and it's Effect on Racing Pigeons, by Bilco
Homing Pigeons have been observed to become confused during space weather disturbances and can even be lost, NASA - Fun Facts
Space weather, Solar Storms & Pigeons