​QUESTIONS AND ANSWERS PAGE

You could call this the 'trivia' page. I often get asked about odd things in weather which many of you may wonder about but never asked. I have listed the most popular questions I get asked and my answers below. I also get asked about weather lore and how accurate old fashioned sayings are. There are some true ones but many are simply myth but I have listed the most popular at the bottom of this page. Hope you find the page interesting.

Popular Questions​​

Why do we sometimes have frost in the valley but not on the hills?


Answer. The reason is the air at higher elevations becomes heavier and sinks as night wears on, pooling in the lowest elevations. In Meteorology this is known as negative buoyancy. The cool air descends hills along the same terrain as rain or snow would run off. When the air reaches the valley floor, it will keep cooling due to continued radiational heat loss as the night wears on.  Cold air pools can be very deep in mountainous areas but can be as small as just a few feet around here. In short, cover your plants if you’re in a valley!


Why are temperatures higher by day in valleys than on higher ground?



Answer. Air density decreases up the hills so does the temperature. Air becomes cooler with altitude because the heat is lost by radiation from the earth and as the air expands, it cools. ... As we go on higher altitudes, pressure decreases, likewise so does the temperature. In mathematical speak that is 9.8°C per 1,000 meters. However, if you're in a cloud, or it is snowing/raining, the temperature decreases by about 3.3°F for every 1,000 feet up you go in elevation. Thus meaning it's a change of 6°C per 1,0000 meters.


Why do showers form more widely near coasts in Winter and inland during Summer?


Answer. In Winter the sea temperature around the UK is higher than that of the land. For showers to form in Winter we need cold air over warm seas and in the UK in a polar airmass that's what we achieve so you will often here a winter weather forecast say showers will be frequent near windward coasts while inland it will stay dry and clear. In Summer however, the land of the UK becomes warmer than that of our surrounding seas and its the inland land mass that is at greatest risk of showers than coastal regions within a similar polar airmass. In Summer this explains why you can often see cloudless skies out to sea whereas inland convective clouds hide the sun at least and at worst produce heavy showers off and on all day.


Why do some nights see fog form while others don't?



Answer. For radiation fog to occur there are two ingredients that are required and they are high humidity and temperature inversions. The temperature contrasts between village and hilltops in still weather is large so if the air is moist enough fog will form on the boundary layers. If the air is too dry or if there is a mixing of air temperatures due to wind then fog cannot form. Advection fog however which is really low cloud sat on hilltops is formed rather differently by 'saturated' air forced to rise and condense on passing over steep hillsides and can occur in windy conditions as well as calm weather.


Did you know that a rainbow is not a bow but part of a circle.


Answer. To view the entire circle you need to be in an aircraft which is fortunate enough to be passing through a shower with sunshine above. The resulting rainbow is a circle directly opposite the sun. On the ground a rainbow is an 'arc' which will be at its most spectaular at sunset when it extends up to a point high in the sky whereas in the middle of the day when the sun is high a smaller portion of the arc only is visible low in the sky always opposite the sun. A rainbow is formed by the refraction of sunrays through the raindrops where it splits the light into the seven colours of the spectrum red, orange, yellow, green, blue, indigo and violet. Interestingly a strong rain bow will produce a secondary bow on the outside of the main bow in which the colours are reversed. Drizzle or very heavy rainfall often produces the brightest rainbows.

 
Why can it be hot and sunny inland in Summer but foggy on the coast?


Answer. As mentioned under the fog question above for fog to warm two ingredients are needed i.e high humidity and temperature contrasts. In early summer especially these are expansive around our coasts. At the same time hot summer sunshine heats the land quickly and under the right conditions enhance that temperature contrast at their meeting point which is the coast. This forms low cloud or sea fog which often plagues our Southern and eastern coasts particularly in summer humid heatwaves.


What defines the term 'near average'?



Answer. The term 'near average' refers to the average temperature, rainfall, wind, sunshine or any other weather parameter achieved by combining the weather records of each over the last 30 years, the deviation from which is quoted as 'below' or 'above' or 'well above' or 'well below'normal.


Do temperatures have to be below freezing for snow to fall and can it be too cold to snow?



Answer. No they certainly do not. However, for snow to form temperatures aloft have to be below freezing to innitiate the process. Determining whether snowflakes reach the ground as snowflakes or not is more difficult to explain but as a ground rule, temperatures of around or under +2C are needed for snow to fall and stick dependent on factors relating to dewpoint. For example in Spring when the air is dry and cold snow can reach the surface in temperatures of as high as +8C in showers but thats the exception rather than the rule. On the other half of the question relating to 'can it be too cold to snow' the answer is no but in the UK as a rule heavy snow tends to fall more heavily and frequently when warmer air is close by delivering our heaviest falls ahead of a transition to rain. Very low sub zero temperatures usually create a different type of snow which is dry and powdery but lighter in nature, usually indicative of a more sustained and longer lasting cold spell.


Is freezing rain 'snow'?


Answer. No. Freezing rain is probably one of the most dangerous of weather parameters that can occur here in the UK. It is formed when there is warm air in the lower layers of the atmosphere while a sub-zero surface air current lies on the surface. Snow then falls from the clouds and descends through the warmer layer of air above where it melts into rain. Then as it reaches the sub-zero air on the surface it freezes instantly on impact. The result is sheet ice everywhere which is lethal to road transport, rail travel and aircraft and can be responsible for many broken limbs from people slipping on surfaces which look wet but are icy. Human nature is also a bit responsible for people not taking precautions as the perception is 'how can it be icy when it its raining' believe you me it can. Fortunately it is quite rare.


What is defined as 'sleet'?



Answer.
Sleet is a term used for rain and snow falling together. It can often be confused with fine snow or snizzle which some people call sleet which is incorrect. Normally with a temperature falling towards around 2C rain will begin to turn to snow visible by the bigger droplets taking on a more snow type form, splatting on car windscreens etc where the smaller droplets remain as rain. This is the true definition of sleet. Often in these situations an observer can look skyward to the clouds and see millions of snowflakes passing overhead at altitude whereas only a few reach the ground as snow, the rest falling as rain.


What is 'soft hail'?



Answer.  Soft Hail is a term described as hail which has more snow like qualities in as much as it is soft and not hard and opaque like standard hailstones. It occurs mostly in showery weather through the Spring months when snow falls from the clouds and partly melts before being thrown in the convective cycle that standard hail forms by reaching the ground as soft balls of snow like polystyrene balls running along on the breeze. They can often turn the ground white in minutes only to melt away again in the warm sun that usually follows.


Why is it still classed as a frost when my car is not frozen over or grass white?



Answer. People often become very confused by the term frost. They think that frost is only a frost when the grass and surfaces like car windscreens etc become white and frozen. This is not so. Technically any condition that is experienced under 0C is a frost. So while most of our UK frosts are accompanied by night time clear skies and light winds creating the picturesque landscapes we are all familiar with there are occasions when frost is experienced under bone dry conditions, cloudy skies and windy weather. This is known as 'black frost' as the only indications of temperatures below 0C are frozen lakes, ponds and any puddles plus your car thermometer. These conditions are most common in cold east winds from Europe in Winter which can be the precursor to snowfall soon.

True, False or Neither. Weather Lore sayings Fact or Fiction?




Red Sky at Night Sailors Delight
Red Sky in morning Sailors Warning

Answer. Neither. It is true that most of our weather comes from the West so this does ring true then but sometimes bad weather comes from the East and its then the saying would reverse the 'delight' and 'warning' words.


Rain before seven, fine by eleven.   

Answer. False. It may occur like that occasionally on the passage of a rain bearing weather front but not reliable.

A sun shiny shower, won’t last half an hour.

Answer. True. Showers rarely last more than half an hour.

Clear moon, frost soon.

Answer. False. Clear moons can occur at anytime of year and we dont have frosts in Summer.

When bees stay close to the hive, rain is close by.

Answer. Neither as it applies to damp atmospheric conditions too when rain isn't necessarily on the way.

Moss dry, sunny sky; moss wet, rain you’ll get.

Answer. False. Moss will be wet after rain, not necessarily just when rain is coming.

When smoke descends, good weather ends.

Answer. True. Smoke falls to the ground when the air is moist and heavily laden swelled by wind, a good sign of rain soon.

A cow’s tail to the west is weather coming at its best;
A cow’s tail to the east is weather coming at its least 


Answer. False. Cows cannot predict the weather. They may face their tail downwind to protect theirselves against what's happening now, not whats to come.

Flies will swarm before a storm.

Answer. True. When flies are numerous in number it often indicates very warm and humid weather when storms are likely.

Fast runs the ant as the mercury rises.

Answer. True. Ants move with great speed when the ground they are travelling on is hot.

If crows fly low, wind’s going to blow;
If crows fly high, wind’s going to die.


Answer. False. They do fly low in current bad weather and high in good weather. They cannot predict whats coming.

No weather is ill if the wind is still.

Answer. False. Severe fogs and frosts occur when the weather is still.

If the moon rises with a halo round Soon we’ll tread on deluged ground.


Answer. True, though I take exception to the word 'deluge'. Rain is often on the way when a haloed moon or sun is observed.

When sea birds fly to land there truly is a storm at hand.

Answer. True. Sea birds come inland for protection in times of storms at sea.

Whether the weather be hot,
Or whether the weather be not;
We’ll weather the weather, whatever the weather,
Whether we like it or not! 

  
Answer. That is of course true.

Pale moon doth rain,
Red moon doth blow;
White moon doth neither rain nor snow.


Answer. False. Cant see too much reliable logic in that one.

When the stars begin to huddle,
The earth will soon become a puddle.


Answer. False. More to do about sky conditions at observation rather than whats to come.

A summer fog for fair, a winter fog for rain.

Answer.
True. Fog in Summer is indicative of high pressure, fog in Winter is associated with high humidity and rain.

When your joints all start to ache,
Rainy weather is at stake

  
Answer.
False. Cant see reliably accurate info to support that.

If February brings no rain,
‘Tis neither good for grass nor grain.


Answer. True as dry in Februry means its likely to be very cold which of course is not good for germination in preparation for the growing season.

March comes in like a lion, goes out like a lamb.

Answer. False. Coincidence if it happens like that. I can give many examples of the opposite occurring.

If Candlemas Day (February 2nd) be fair and bright,
Winter will have another flight;
But if Candlemas Day be clouds and rain,
Winter is gone it will not come again 


Answer.
False. The calendar days do not predict the weather.

April showers bring May flowers.

Answer. True. April showers coupled with the higher and warming sun does indeed bring forth May flowers.

If it thunders on All Fools’ Day,
It brings good crops of corn and hay.


Answer. False. Once again the calendar days cannot predict the weather.

Cast not a clout ‘til May be out'

Answer. Neither. If a cold spell in May is experienced this may be true but many a hot spell has occurred long before May when many a clout has been cast.

A dripping June keeps all things in tune.

Answer. Neither. A dripping June is good for growers for future crops but not good for those who seek warmth and dry summer weather.

A dry May and a dripping June,
Make the farmer whistle a happy tune.


Answer.
True. For farmers in particular that is a true statement.

Mist in June will bring all things into tune.


Answer. True. Mists in June morning's mean settled conditions and warm weather.

St Swithin’s Day (July 15th) if it do rain,
For forty days it will remain.
St. Swithin’s Day an’ it be fair,
For forty days ‘twill rain no more.


Answer. False. One of the worst weather lore sayings yet probably one of the best known. I have evidence to support this is rarely if ever correct.

If the 24th August be fair and clear,
Then hope for a prosperous Autumn that year.


Answer. False. Calendar dates cannot predict the weather to come.

In October dung your field
And your land its wealth will yield.


Answer. True. Winter rains will help the nutrients soak into the soil for prosperity next year.

A tough apple skin means a hard winter.

Answer. False. No evidence to support this theory.

Snow like cotton, soon forgotten
Snow like meal, it’ll snow a great deal.


Answer. True. Heavy weight fuffy snowflakes indicate warmer air nearby while fine powdery snow means loner lasting severe cold is responsible.

A wet January, a wet spring
A year of snow, a year of plenty.


Answer. Neither. This saying misses out on the Summer which for the rest to fit in would need to be warm and sunny.