Frigid Airmass to Bring Significantly Colder Temperatures; Snow Continues Downwind of the Great Lakes

A frigid cold airmass will bring significantly colder weather across the eastern two thirds of the country early this week. Record low temperatures are expected in the Southeast by Tuesday morning. Moderate to heavy lake effect snow will continue downwind of the Great Lakes through Monday. Several inches of snow accumulation is expected, including in portions of the Chicago Metro Read More >

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

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Frigid Airmass to Bring Significantly Colder Temperatures; Snow Continues Downwind of the Great Lakes

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