Weather forecast terminology

Terminology used in weather forecasts and storm warnings

Weather forecasts indicate cloud cover, precipitation, weather events, wind, minimum air temperature for the night and maximum air temperature for the day.

Storm warnings indicate only those events that, according to their criteria, belong to dangerous phenomena or natural hydrometeorological phenomena, sudden changes in the weather.

Dangerous phenomenon (hereinafter - OYA) – a phenomenon that significantly hinders or hinders the activities of certain sectors of the economy and in its quantitative values does not reach the criteria of a natural hydrometeorological phenomenon;

Natural meteorological phenomenon (hereinafter - OHS) – meteorological, hydrological phenomenon that upon reaching certain criteria (intensity, duration and distribution) is a threat to the safety of people, which potentially has the ability to inflict significant damage to the sectors of the state economy and cause disasters or emergency situation;

Local natural hydrometeorological phenomenon – a phenomenon that has reached the criterion of a natural phenomenon, observed on an area of limited size, caused by special terrain conditions in the vicinity of a meteorological station;

Sudden changes in the weather (hereinafter – RIP) - weather conditions in which meteorological phenomena in intensity do not reach the criteria of natural disasters, but hinder the production activities of individual sectors of the economy and the population;

Storm warning-forecast of occurrence, preservation, strengthening of OYA, OHS, RIP.

The terms used in cloud forecasts and their corresponding quantitative characteristics are given in table 1.

Terms used in precipitation forecasts

Forecasts indicate the quantitative characteristics of precipitation, its phase state, and the start time or duration. The terms for precipitation and their corresponding quantitative characteristics are given in table 2.

To characterize the phase state of precipitation, use the terms: "rain", "snow", "rain with transition to snow," "snow transition in the rain", "precipitation". The term "precipitation" is used at air temperatures from plus 5°C to minus 5°C.

The terms shown in table 3 are used to describe the duration of precipitation.

Terms used in weather forecasts

Forecasts indicate the following weather events: snowstorm, low-level snowstorm, snowfall, dust storm, fog, squall, hail, tornado, thunderstorm, ice, frost, frost.

Terms used in wind forecasts

The forecasts indicate the direction and speed of the wind. The wind direction is indicated in the quarters of the horizon (where the wind blows from). The wind speed is indicated at intervals of no more than 5 m/s. Wind speed of 15-29 m / s is considered a dangerous weather phenomenon( OYA), 30 m/s or more – a natural hydrometeorological phenomenon (OHS).

Terms used in air temperature forecasts

Weather forecasts indicate the minimum temperature for the night and the maximum temperature for the day.

The minimum and maximum temperature for the point is specified in the range of no more than 2°C, and for the territory-5°C. It is allowed to specify the temperature by a single number, for example, about 20°C, which means that 19-21°C is expected in the point, 18-22°C in the territory. It is allowed to specify the temperature with the preposition "to"for a part of the territory. For example: 20-25°C, in the East up to 35°C (this means 30-35°C).

If the temperature of the air or soil surface is expected to drop to negative values during the growing season, the term "freezing" is used, indicating the minimum temperature.

If the air temperature is expected to change by 10 ° C or more (maximum, minimum, abnormal course), the term "strong cooling (warming)" or "sharp decrease (increase)" of the temperature is used.

The OJ and OHS criteria for temperature prediction are shown in table 4.

Terms for indicating the time of occurrence and end of precipitation, OYA, OHS

In daily weather forecasts, their updates, and warnings, the terms shown in table 5 are used to indicate the time when precipitation occurs or ends.

In daily weather forecasts and warnings that are made more than 12 hours in advance, if it is not possible to apply the terms from table 6, the term "night" or "day"is used.
Terms for specifying the part of the territory where precipitation, phenomena, temperature, and wind are expected that differ from the main background

Either a single forecast (warning) is made for a territory if the weather pattern is expected to be uniform, or a clarification is made for certain areas of the territory if the weather pattern for these areas is expected to be different. The division of territory into parts should be based on administrative or geographical features (Western and Eastern; in the East, in the center; in mountainous and foothill areas, etc.).

If the weather conditions make it impossible to identify a certain part of the territory where precipitation or weather events are expected, then the use of the term "in places" or "in certain areas"is allowed.

In cases where there is not sufficient confidence in the occurrence or absence of precipitation or weather events, specialized weather forecasts for the media are allowed to use the term "possible","unlikely".