Sunday, April 20, 1952
ASK THE WEATHERMAN
(CBC Trans-Canada Network)
BREAKING IN YOUR WEATHER GLASS
by
P. P. Saltzman,
Dominion Public Weather Service, Toronto.
All right, so you've got your weather glass hanging there on the wall all shiny and looking right pretty. What next?
Well, you can use it to help you forecast the weather a bit better than your pet corn but there's one thing you should know right off the bat and that is although your wall barometer is the most important single tool to do the job right, you can't depend on it alone.
You have to use it together with the wind, the sky, the weather and the geography. You have to use it wisely and with care. You can't read it like the face of a clock. Especially don't depend on the words or numbers printed on the dial, for what counts is not where the black hand points to now, but where it was before and where it is going to move next, and how fast.
Your weather changes because the weight of the air overhead changes. The weight of the air shows on weather maps as high pressure areas and low pressure areas which move about the country. Generally these areas move from west to east which explains why our weather also moves from west to east. High pressure weather is generally fine weather, while low pressure stuff is usually foul.
As these pressure areas move in, over and past your place, your weather glass faithfully shows the change in the weight of the air overhead. The faster the pressure areas move, the faster the black hand moves. It's like a speedometer clocking the rate of rise and fall of air pressure.
Your job is to set the red reference hand over the black, tap the glass regularly at least twice a day and the n see whether the pressure has risen, fallen, or stayed steady, and also to check how fast all this has been happening. You know of course that when the black hand moves to the right, pressure is going up and when it moves to the left, pressure is going down.
Now when I say the black hand moves fast, don't think of the hare, think of the turtle. It takes at least three hours, sometimes six and often 12 hours for the black hand to move a few notches along the dial. Sometimes a day may go by and no motion at all, because the pressure areas have hardly moved. Then you say 'the glass is steady'. This happens especially in the summer time and your weather glass will surely seem sluggish. But don't hurry it. It'll pick up in winter and the old black hand will start to swing back and forth a lot faster as the winter storms zing by in high gear. Then nearly every day it will be--barometer rising, barometer falling.
It won't take you long to learn the ways of your weather glass, especially if you go to a little trouble about it. Read it regularly and carefully. Stand in front of it, not off to one side, and look it full in the face. Tour best bet is to keep a little black book for the record. It's not hard and soon gets to be a treat. Just note down at set times your barometer reading, its rate of rise or fall, the wind direction (outside of course) and the actual weather--fair or foul, scowl or smile. Do this and in a few short weeks ,you'll gat the habit regular--nature's remedy, spelt frontwards.
And here's what you'll learn the easy way: Bad weather's acomin when pressure is falling. The faster it falls, the worse the weather, the sooner it'll come and the faster it'll pass. A slow steady fall means nasty weather lasting for several days.
Barometer steady--means little change. If the weather is already dry and the temperatures just right for the time of year, a steady glass means continued good weather. But if it's raining, then a steady glass simply means more of the same--no change.
Barometer rising--ah, that's the fair weather friend. A good steady gradual rise means settled weather and the slower the rise, the better.
Now you can generally rely on these rules but not always. Like tall stories, you should take your weather glass with a grain of salt. This is because air pressure is only one weather sign--and one sign doesn't make a midway, let alone the weather. You need other signs--the sky, for instance, and the wind.
It's an ill wind that doesn't tell you something. But you have to notice it first. Surprising how many people--especially city people--never notice the wind's direction. Country folk have the habit of noticing the way the smoke blows, the way tree leaves flutter, the waves 'along the lake, the clouds scudding across the sullen sky. Watching the wind is a worthwhile habit. That way you too can learn a lot.
You'd learn for instance that a northwest wind is a good sign. Add to that a rising barometer and you have a pretty fair forecast--settled. clearing, fine weather. In winter you can add to that--colder. Fair and colder, then, with a northwest wind and a rising glass.
But with the wind in the east, it's not so good for manor beast-- as the saying goes. East wind and a falling glass--soon rain will come to pass. Many of our worst storms are heralded by a nasty biting east wind, which gets stronger and nastier as the glass falls. Severe gales and drenching, downpours are in store when the glass hits the floor. And the faster the wind, the faster the bad weather 1s moving in. and the worse it will be, and the sooner it'll pass.
So the weatherwise look to the glass and to the wind and to the clouds and colors of the sky to tell what's ahead. But the weather's a witches' brew and you have to toss in another ingredient before you're through. Geography. Your location. Where you live. Valley or mountain, forest or plain, lake or sea.
Take that northwest wind and a rising glass I mentioned a moment ago--as good a sign as you could want of fine weather. But the people who live in Ontario along the shore of Lake Huron would laugh at that in winter. For down there in winter when the air is cold and the lake is not, a north west wind coming off the lake dumps tons of snow on their weary bones. Down there, we might say, when winter comes and they see a nor'wester, barometer rising Of not~ they take another hitch in their snowbelt and buckle down for the worst.
Mix it all together--wind and weather, sky and sun, weather glass and all--and then and only then can you hope to do a good forecast--maybe.
For if it were all that simple, your official forecaster would soon be out of a job--and then you would be able to say in simple faith ...
Weather glass, weather glass on the wall
Will you rise or will you fall?