I am sure there was a time when weather presenters on television specifically mentioned what the lowest overnight temperature would be and where they expected it to occur, but that rarely seems to happen in these enlightened times. They must be well versed in the book of Dodges for weather presenters, dodge one in that book warns to never specify a value (unless it’s been provided to you in a warning) because if you do some smart Alec (me for instance) can come along and point out that you were totally wrong.
That didn’t happen last night because the presenter used the good old “temperatures in towns and cities” chart. Using this will ensure that the viewing public will be left guessing how cold it will get in their particular locale. They will probably be asking themselves: Am I in a village or is it a town? Is it rural even though it’s on the edge of a city? Use of this chart means that they can forget the specifics because for some inextricable reason they know for certain that the viewer knows the -1°C to the left of Inverness is actually the minimum temperature for the city and for where he lives it will be closer to -6°C.
To make matters worse the chart used last night in the BBC forecast rather unhelpfully didn’t include any coloured isotherm which made it impossible to gauge the extent and severity of the frost. Minimum temperatures between -2.6 and -6.4°C are classified as a moderate frost by the Met Glossary, but even the mention of helpful terms like this seem too passé these days for our new elite band of presenters.
The reason I get so riled is that for the second night in a row the moderate frosts we’ve experienced in northern Scotland in my opinion were very poorly forecast. The graphics employed are misleading, and must give the viewer the impression that temperatures in northern Scotland at 05 UTC would be around -1°C when in fact they were in the range -4°C to -6°C. Yes it’s true the presenter did mention the possibility of a frost but neglected to specify the severity or extent other than saying they would be widely down to freezing in rural parts.