When it comes to choosing a shell jacket, there are a few key factors to consider in order to find one that is both comfortable and secure against wind and rain. Here are some tips to help you make the right choice.

1. Waterproofing: Look for a jacket that is made with a waterproof material, such as Gore-Tex or a similar waterproof, breathable membrane. These materials will help to keep you dry in wet conditions.

2. Breathability: It's important to choose a jacket that is breathable, as you don't want to get too hot and sweaty while wearing it. Look for a jacket with vents or mesh panels to help regulate your temperature.

3. Fit: Make sure the jacket fits well and is comfortable to wear. It should be loose enough to allow for layering underneath, but not so loose that it feels bulky or cumbersome.

4. Wind resistance: A shell jacket should be able to withstand strong winds and keep you warm. Look for a jacket with a wind-resistant outer layer and a fleece or insulated lining to help keep you warm.

5. Hood: If you'll be wearing the jacket in wet or windy conditions, consider getting one with a hood. Make sure the hood is adjustable and fits well, as it can help to keep you warm and dry in bad weather.

6. Pockets: Look for a jacket with plenty of pockets, as these can be useful for carrying small items like keys, phones, or wallets.

7. Durability: Choose a jacket that is made with durable materials and is built to last. Look for reinforced areas like the elbows and shoulders, as these areas tend to get a lot of wear and tear.

Overall, choosing a shell jacket that is both comfortable and secure against wind and rain requires careful consideration of the jacket's materials, fit, and features. By following these tips, you can find a jacket that will keep you protected and comfortable no matter the weather.