Atmospheric pressure | Baroclinity | Cloud | Convection | CAPE | CIN | Dew point | Heat index | Humidex | Humidity | Lightning | Pot T | Precipitation | Sea surface temperature | Surface solar radiation | Surface weather analysis | Temperature | Theta-e | Visibility | Vorticity | Wind chill | Water vapor | Wind January 1 is the first day of the calendar year in both the Julian and Gregorian calendars. ... 1989 (MCMLXXXIX) was a common year starting on Sunday of the Gregorian calendar. ... This is about the Dutch city of Dordrecht. ... Holland is a region in the central-western part of the Netherlands. ... Satellite image of Hurricane Hugo with a polar low visible at the top of the image. ... Diurnal (daily) rhythm of air pressure in northern Germany (black curve is air pressure) Atmospheric pressure is the pressure at any point in the Earths atmosphere. ... It has been suggested that Baroclinic instability and Baroclinic vector be merged into this article or section. ... Cumulonimbus capillatus incus floating over Swifts Creek, Victoria in Australia A cloud is a visible mass of condensed droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. ... Convection is the internal movement of currents within fluids (i. ... In meteorology, convective available potential energy (CAPE) is the amount of energy a parcel of air would have if lifted a certain distance vertically through the atmosphere. ... Convective inhibition (CIN or CINH) is a meteorlogic parameter that measures the amount of energy that will prevent an air parcel from rising from the surface to the level of free convection. ... Dew on a spider web The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. ... The heat index (HI) or humidex is an index that combines air temperature and relative humidity to determine an apparent temperature — how hot it actually feels. ... Heat Index (HI) is an index that combines air temperature and relative humidity to determine an apparent temperature — how hot it actually feels. ... Humidity is the concentration of water vapor in the air. ... Lightning is an atmospheric discharge of electricity, usually, but not always, during a rain storm. ... The potential temperature of a parcel of air at pressure is the temperature that the parcel would acquire if adiabatically brought to a standard reference pressure , usually 1 bar. ... Visualisation of the SST of the ocean just before Hurricane Bob (August 14, 1991) Sea surface temperature (SST) is the water temperature at 1 meter below the sea surface. ... Solar irradiance spectrum at top of atmosphere. ... A surface weather analysis for the United States on October 21, 2006. ... Fig. ... Equivalent potential temperature, commonly referred to as Theta-e , is a measure of the instability of air at a given pressure, humidity, and temperature. ... In meteorology, visibility is a measure of the distance that can be seen clearly at any given time. ... Vorticity is a mathematical concept used in fluid dynamics. ... Wind chill is the apparent temperature felt on the exposed human (or animal) body due to the combination of air temperature and wind speed. ... Water vapor, also aqueous vapor, is the gas phase of water. ... Wind is the rough horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earths surface. ...