National Weather Service United States Department of Commerce

Late January Extreme Cold; Watching East Coast Storm Threat This Weekend

The next blast of Arctic air surges south down the Plains, across the Great Lakes and through the Southeast and East Friday through Saturday. This could be longest duration of cold in several decades. Forecast models are being closely monitored for potential of another significant winter storm to impact the eastern United States this coming weekend. Confidence in coastal impacts has increased. Read More >

 

Pictures from around western Colorado and eastern Utah
What is "Z" Time?

Since weather observations and forecasts are provided around the globe, it is important to understand when each piece of data is valid for. To overcome the problem of numerous time zones, it was internationally agreed upon that weather time stamps would be based on the Prime Meridian, or Greenwich Mean Time (GMT).

Other names for GMT include Universal Time Coordinated (UTC) or "Z" Time.
In the Mountain Time Zone:

Z = MST + 7 hours
Z = MDT + 6 hours
or
MST = Z - 7 hours
MDT = Z - 6 hours


examples: 11 am MST = 1800Z (6:00 pm GMT)
or
1800 MDT (6:00 pm) = 0000Z (Midnight the next day GMT)

Map of World Time Zones