Weather Glossary - U
Search
UKMETA medium-range numerical weather prediction model operated by the United Kingdom METeorological Agency. |
Ultraviolet radiationElectromagnetic radiation with wavelengths shorter than visible light, but longer than x-rays. Exposure to too much UV radiation can cause skin cancer. |
UnsettledChangeable or variable weather. |
Unstable airAir in which static instability exists. This condition is determined by the vertical gradients of air temperature and humidity. |
UpdraftA small-scale current of rising air. If the air is sufficiently moist, then the moisture condenses to become a cumulus cloud or an individual tower of a towering cumulus or Cb. |
Updraft baseAlternate term for a rain free base. |
Upper levelThe portion of the atmosphere above the lower troposphere. It is generally applied to levels above 850 hPa. |
Upper level systemA general term for any large-scale or mesoscale disturbance capable of producing upward motion (lift) in the middle or upper parts of the atmosphere. This term is sometimes used interchangeably with impulse or shortwave. |
Upslope flowAir that flows toward higher terrain, and hence is forced to rise. The added lift often results in widespread low cloudiness and stratiform precipitation if the air is stable, or an increased chance of thunderstorm development if the air is unstable. |
Upslope fogFog that forms when warm moist air is forced up a slope by wind. |
UpstreamToward the source of the flow, or located in the area from which the flow is coming. |
UpwellingThe rise of colder, deep ocean waters along a coast due to the movement of surface water away from the coast. |
UTCAbbreviation for Universal Time Coordinate. See also Zulu, GMT. |
-
Display your Local Weather here
automatically each time you visit us:
Rotates through Temperature,
Wind, Humidity and RainUse the Search Bar above
to find your Local, and go to the Local page
Click "Set My Local"
button next to the location name
Weather News
NT weather: Four found, two missing after vehicles become stranded
09:22 EDT
An aerial search will start today for two people believed to be walking to the flooded community of Kintore after their vehicles became stranded.
SA weather: Adelaide storm cuts power, leave trail of destruction
09:11 EDT
Traffic lights are out, cars have been damaged by falling debris, and some properties will remain without power for 24 hours after a powerful storm rolled through Adelaide overnight.
Victoria weather: BOM issues severe weather warning for damaging winds, heavy rain
08:44 EDT
A severe weather warning has been issued for most of Victoria, with heavy rain and damaging winds expected to bring flash flooding.
