Pivotal also mentions that the Canadian is the most accurate for cloud cover predictions, but I find it --REALLY-- hard to believe that cloud cover up here will only be 5-10%. That almost never happens in April.
https://www.pivotalweather.com/eclipse2024/?m=cmceens&p=cloudcover_tle_4-mean&r=us_state_ny
The Canadian ensemble (CMCE) runs twice daily, with new maps typically available by 4:00 AM and PM EDT (1:00 PDT). Its forecasts for cloud cover are the most nuanced and realistic available on this page.
The American ensemble (NCEP GEFS) runs four times daily, with new maps available every 6 hours. Its forecasts for cloud cover can tend to overestimate coverage where the sky will only be partly cloudy, while its precipitation forecasts are realistic and useful.