Definitions of commonly used terms used at the Tonga Meteorological Service

State of the Sky

English

Tongan

Definition

Fine, Clear or Sunny

‘Alomalie, Tafitonga

No clouds or with a few light clouds (<0 to 2 okta or less than 1/8 to 2/8 of sky covered with cloud) and no rain

Mainly or Mostly Fine/Sunny

Lahi ‘alomalie

Fine or Sunny most of the time

Partly Cloudy

‘Ao’aofia fakakonga

Cloud is between 3 to 4 okta (3/8 to 4/8 of sky covered with cloud)

Cloudy

‘Ao’aofia

Cloud  is between 5 and 7 okta (5/8 to 7/8 of sky covered with cloud) or at least 60% of the time

Cloudy periods or Cloudy at times

‘Ao’aofia ha ngaahi taimi

Cloudy for spells of about an hour or so throughout the forecast period

Mostly Cloudy

Lahi ‘ao’aofia

Cloudy for most of the time but with brief periods of sunshine

Overcast

Fakapopo’uli

All of the sky is covered with cloud (8 okta)

Precipitation

Rain

‘Uha

>> Water droplets that fall through the atmosphere with droplets >0.5mm in size

>> Rain refers to continuous and steady precipitation which may lasts     

      several hours & usually occurs when the sky is overcast normally

      associated with large scale systems like fronts and troughs

Light  Rain

‘Uha ma’ama’a

The rain rate is usually from above 0mm to 2.5mm per hour (puddles form slowly)

Moderate (Medium) Rain

‘Uha

The rain rate is usually from 2.5mm to 7.5mm per hour (puddles rapidly forming  and down pipes flowing freely)

Heavy Rain

‘Uha Lahi

Rain typically more than 7.5mm per hour or about 50mm in 6hrs (continuous, falls in sheets, misty spray on hard surfaces and may cause roaring noise on roof)

Occasional Rain

‘Uha fakataimi

Not frequent but recurrent rain

Frequent Rain

‘Uho’uha

Rain occurring regularly through out a forecast period

Showers

‘Uha tu’u mo tō

Precipitation for short duration (Brief) but of usually greater intensity  from convective clouds (cumulus or cumulonimbus). Characterized by sudden beginning and sudden end of precipitation.

A few showers/Some showers

‘Uho’uha tu’u mo tō

Means that there will be brief periods of rain in the forecast area but  not all areas will get rain

Light showers

‘Uha tu’u mo tō  ma’ama’a

Brief periods of light rain

Occasional showers

‘Uha tu’u mo tō ‘i ha ngaahi taimi

There is a large number of convective clouds and precipitation occurs in most part of the forecast area occasionally and varying in intensity

Scattered showers

‘Uho tu’u mo tō tō tō holo

The precipitable clouds are distributed spatially resulting in showers to the larger part of the forecasted area.

Isolated showers

‘Uho tu’u mo tō fakafeitu’u

The precipitable clouds are distributed spatially resulting in showers to the lesser (smaller) part of the forecasted area.

Squally showers

‘Uha tu’u mo tō tō takutaku

Showers accompanied by brief but sudden strong or gale force winds

Wind

Light winds

Angi iiki

Average winds less than 10kts

Moderate winds

Angi mamalohi

Average winds between 11 to 16kts

Fresh winds

Angi mamalohi ke malohi ange

Average winds between 17 to 21kts

Strong winds

Angi hako pe hakohako

Average winds between 22 to 33kts

Gale force winds

Matangi malohi fakatupu maumau

Average winds between 34 to 47kts

Storm force winds

Matangi Afaa pe matangi malohi fakatupu maumau lahi

Average winds between 48 to 63kts

Hurricane force

Matangi Afaa malohi pe matangi malohi fakatupu maumau lahi ‘aupito

Average winds ≥64kts

Severe Tropical Cyclone

Saikolone fakatalopiki Malohi

A tropical cyclone with average sustained winds ≥65kts