UCAR - see University Corporation for Atmospheric Research

UKMET - a medium-range (3-7 day) numerical weather prediction model operated by the United Kingdom Meteorological Agency. It has a resolution of 75 kilometers and covers the entire northern hemisphere. Forecasters use this model, along with the ECMWF and GFS, in making their extended forecasts (3 days and longer).

Ultraviolet Radiation (UV) - radiation having a wavelength shorter than wavelengths of visible light and longer than those of X-rays

Universal Coordinated Time (UTC) - a global time scale based on the local time observed on the Prime Meridian; also called Greenwich Mean Time (GMT) or Zulu (Z) time

University Corporation for Atmospheric Research (UCAR) - a nonprofit, Colorado-based corporation that receives and manages funds and administrative functions for NCAR. It includes several universities that are dedicated to the advancement of atmospheric and related sciences

UNSBL - unseasonable

Unsettled - a colloquial term used to describe conditions in the atmosphere favorable to the creation of precipitation. This term typically is associated with the passage of surface or upper level low pressure systems, fronts, or other phenomenon where precipitation is expected.

Unstable Air - generally, air that will continue to rise and accelerate when briefly forced upward

UNSTBL - unstable; see Unstable Air

Updraft - a relatively small-scale current of air with marked upward motion

UPR - upper

Upslope Flow (UPSLP) - air that flows toward higher terrain and, hence, is forced to rise

Upslope Fog - a fog that forms as moist air is forced up a hill or mountain.

Upslope Precipitation - precipitation that forms due to moist, stable air gradually forced upward along an elevated plain (e.g., the Rocky Mountains)

UPSLP - upslope; see Upslope Flow

Upstream (UPSTRM) - toward the source of the flow, or located in the area from which the flow is coming

UPSTRM - see Upstream

Upward Vertical Velocity (UVV) - rising air

Upwelling - when cool, nutrient-rich water rises from deep in the ocean up to near the surface.

Upwelling Radiation - the component of radiation (either reflected solar or emitted terrestrial) directed upward from the earth’s surface; opposite of downwelling radiation

UT - Utah

UTC - see Universal Coordinated Time

UV - see Ultraviolet Radiation

UVM - upward vertical motion; see Upward Vertical Velocity

UVV - see Upward Vertical Velocity

UWNDS - upper level winds