2m Temperatures

These charts represent air temperatures near the durface or at distance of 6 metres or 2 feet above the ground. Professional readings are taken from stations around the world and are gathered and collected in onservartions around the world. Yellow and organge colours represent mild air whilst blue and even purple reflect cold air

Cloud Cover

These chart are the easiest to read as they represent how much cloud cover is expected at each time interval. Out of 100% total coverage is forecast and 0% indicating no cloud cover. Colours vary from grey to white with the darker colours indicating more cloud coverage.

500hpa Temperatures

Although complicated these charts are quite easy to understand. The white lines and numbers reflect pressure at the surface with the "T" being a trough and "H" being a high. A trough represent a low and a high is that of an anticyclone  butthese charts show upper lows and upper highs at 500mb and as well surface which is at 1000mb . The colours represent temperatures at 500mb or 5600 metres about 18,300 feet above the surface. The yellow and orange colours indidcate mild or warm temperatures at 500mb and the blue and purples how cold the air. The black or thick line represents the freezing level 0C.

Under 500hpa lows precipiation tends to be more extensive even if more showery and if lows and highs are both at upper and lower levels then blocking is very likely especially if two anticyclones are located at the surface and upper levels and this can bring days or weeks of dry weather.

850hpa Temperatures

Similar to 500hpa temperatures charts but these charts are different as they represent the level of atmosphere that is not affected directly from the sun like the loss of daytime heating or cooling at night. The advantage is that these charts show consistency in forecasting unlike surface or 2m temperatures which can vary compared to these charts (as for example 5C at 850hpa could be 5C at surface). These charts represent temperautres at 850mb or about 19,500 feet above the surface. Yellow and oranage colours reflect mild airmasses wtih blue and purples the coldest air masses. Temperatures at 850 mb are higher thna those of 500m as temperatures decrease with height. The key thing here is these temperatures are NOT surface temperatures.