To start using the Weatherstack API, sign up at their website to obtain an API key. This key is essential for authenticating requests to the API and accessing weather data.

Ensure you have the necessary libraries installed for making HTTP requests and interacting with Redis. If you're using Python, install `requests` for HTTP requests and `redis-py` for interacting with Redis:
```bash
pip install requests redis
```

Write a script to make an HTTP GET request to the Weatherstack API using your API key. Specify the endpoint and the necessary parameters to fetch the required weather data:
```python
import requests

api_key = 'your_api_key'
base_url = 'http://api.weatherstack.com/current'
location = 'New York'

response = requests.get(base_url, params={
'access_key': api_key,
'query': location
})

if response.status_code == 200:
weather_data = response.json()
else:
raise Exception("Error fetching data from Weatherstack")
```

Extract and prepare the relevant data from the JSON response received from Weatherstack for storage in Redis. Identify the specific fields you need (e.g., temperature, humidity) and structure them as needed:
```python
data_to_store = {
'temperature': weather_data['current']['temperature'],
'humidity': weather_data['current']['humidity'],
'wind_speed': weather_data['current']['wind_speed']
}
```

Establish a connection to your Redis database using the `redis-py` library. Ensure Redis is running on your server or local machine, and configure the connection parameters as needed:
```python
import redis

redis_client = redis.StrictRedis(host='localhost', port=6379, db=0)
```

Use the Redis client to store the prepared weather data. You can store data as a hash, string, or in any other suitable Redis data structure. For storing multiple key-value pairs, a hash is often suitable:
```python
redis_key = f'weather:{location}'
redis_client.hmset(redis_key, data_to_store)
```

To keep the weather data in Redis up-to-date, schedule your script to run at regular intervals using a task scheduler like `cron` on Linux or Task Scheduler on Windows. This ensures the data is refreshed periodically:
- On Linux, add a cron job by editing the crontab with `crontab -e` and adding a line like:
```bash
*/30 * * * * /usr/bin/python /path/to/your/script.py
```
- On Windows, use Task Scheduler to set a repeating task for the script.

By following these steps, you can effectively transfer weather data from Weatherstack to Redis without relying on third-party connectors, ensuring a streamlined and direct data flow process.