Pearl Izumi Barrier Cycling Jacket
The Barrier jacket from Pearl Izumi Clothing is designed as a lightweight outer shell that is suitable for cold days out on the bike where you need a bit of protection from the wind and rain. It's not a full waterproof rain jacket, though the beauty of the Zephyrr is that is way more breathable than a heavier waterproof, and means you won't get sweaty as you warm up on the bike. It will still keep you warm when an unexpected shower drops in, and the Pearl Izumis own ELITE Barrier fabric provides superior wind shielding on crisp mornings. It's lightweight design makes it pack up into an impressively small size making it ideal to always have in your backpack or jersey pocket should the weather turn sour. 
Unlike regular rain coats or products from camping stores, the Barrier jacket uses a cycling specific fit that is contoured to your body when on the bike, with more coverage around the tail to keep your bum dry, while the elastic hem and cuffs keep the jacket in place whether you're moving or not. Although the ELITE fabric breaths well, additional venting is provided around the arm pits to keep you from getting sweaty on those longer rides, and the full length zip gives you the flexibility to open up the jacket should you need to.  

From Pearl Izumi:

"Wind-proof and water resistant, this comfortable and breathable Barrier Jacket provides lightweight, packable protection from a wide range of weather conditions"

The Pearl Izumi Barrier Jacket features: