Frequently asked questions (2024)

UTC literally stands for Universal Time Coordinated (though it is typicallyreferred to as Coordinated Universal Time) and is the standard time commonto every place in the world. It is also known as Greenwich Mean Time(GMT) and Zulu (Z). UTC is defined as the time at longitude 0 degrees,the prime meridian. This is the longitudinal line that separatesthe Eastern and Western Hemispheres, and happens to pass through the GreenwichObservatory outside of London, England. All of our forecast productsand the computer models that provide us guidance are based on this universaltime zone.

When you see 12 UTC or 1200 UTC or 12Z (all are the same and dependon forecaster preference), it refers to noon at Greenwich. 00 UTCor 00Z is midnight Greenwich time. Translating this to your timezone depends on where you live. Below is a table that provides someUTC times and their conversion to the 4 main time zones over the lower48 for standard time.

STANDARD TIME

So, for example, if we write 12Z Friday, it’ll be 7:00 a.m. EasternStandard Time and 4:00 a.m. Pacific. If it’s 00Z Friday, it willbe 7:00 p.m. Thursday Eastern and 4:00 p.m. Thursday Pacific.

The table below is for daylight time.

DAYLIGHT TIME