There is some speculation to what extent dogs can predict the weather.  However, due to their heightened senses, it is presumed that they may be able to predict weather patterns sooner, and in ways humans cannot.

Here are five theories we found about how dogs predict inclement weather:

1.     Dogs are more sensitive to drops in barometric pressure than humans. This drop in pressure may be a precursor to a storm, so dogs associate this drop with a storm and begin to anticipate it.

2.     Dogs may be able to sense changes in static electric fields when a thunderstorm is on its way.

3.     The theory exists that dogs can feel the small vibrations that precede a storm—a rumble too small for humans to notice.

4.     If thunder is present, dogs can hear it far sooner than humans because their ears are more sensitive to higher and lower frequencies.

5.     Due to the high sensitivity of a dog’s sense of smell, they may be able to detect precipitation through their noses.  They may even smell the ionization of the air caused by lightening.

Resources:

http://www.petplace.com/dogs/how-do-dogs-sense-oncoming-storms/page1.aspx

http://www.answerbag.com/q_view/2017632