Weather Glossary - Z
Large-scale atmospheric flow in which the east-west component (i.e., latitudinal) is dominant. The accompanying meridional (north-south) component often is weaker than normal. Compare with meridional flow. Weather systems tend to move past quickly in a zonal flow regime.
Greenwich Mean Time (GMT). Centred on zero degrees longitude. For scientific purposes this time zone is also known as Universal Time (UTC). All meteorological observations worldwide are reported using this time (for ease of comparison and computation). This timezone is commonly suffixed with 'Z'.
Melbourne has chilled through its coldest pair of days this late in the year since 1983, reaching a footy-season like 13.2 degrees on Saturday and 14.2 on Sunday.
Following a nice Sunday to end the weekend, the mercury is set to plunge on Monday as a cold front welcomes the working week.
Hail storms, heavy rain and gusty winds have lashed Victoria and hundreds of people have called for help from emergency services as a cold front moved across the state.