COLUMN: Weather Wise with Gordon Currie

The endless cycle of life on our fields. (S)
The endless cycle of life on our fields. (S)
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More meterological musings from the Gazette’s weather columnist, Gordon Currie, plus prospects for the week ahead:

Evening grey;

The last faint gleam is fading

From the sky;

The flowers of spring’s green

Promise, where are they?

Methinks the gathering makes

Sad reply :

“ Gone with the flying hours, that

Ceaseless sweep

O’er time’s wide, shoreless sea,

So lone and deep . . . ‘’

The poet’s lamentations upon the seasonal course of the year as we approach the end of August probably reflect the feelings of many people, especially when the last few months had so much catching up to do and the brilliance of high summer has passed so swiftly by. Why indeed should we contemplate the autumn season so soon? The modern world sees us relaxing on foreign beaches far beyond August, so why should we dwell upon autumn at this premature stage? Maybe it is worth remembering that our forefathers defined the beginning of autumn as the first day of August. Undeniably, they had a point, as they watched the evening sun dipping towards the blue frills of the far distant outlined trees, and the sunset rays beginning to accentuate the flushing cheeks of the orchard apples. Through the month of August, the manufacture of autumn colours begins to forge ahead, beneath nature’s concealment of summer foliage, which, by the end of the month, gives the impression of September resting upon summer’s laurels. A few days ago, I noted the first few yellow leaves on our wild plum tree, premature messengers of weeks to come.

It is difficult to know where to start when we begin to study of strategy of September’s weather because there can be so many variations of mood. Certainly, the artistic and the romantic captures our eye, especially in the farming scene. Who can deny the charismatic linkage between the end of one farming year and the beginning of the next?

A simple glance at the way in which the early morning sunshine transforms the hues of stubble fields into pure, shining gold contrasting alongside the shining chocolate brown earth of the first furrow to be turned on the ploughland. Once again, it comes down to the unbreakable thread on continuity on the land, between conclusion of one harvest and the commencement of the next. It is strange how we tend to romanticise about the weather of September, the “ golden phase ‘’ of summer’s late happy-medium warmth when John Keats’ poetic bees worked until they thought : “ warm days would never cease, for summer had o’er brimmed their clammy cells.’’ This particular repute of lingering summer warmth and peacefulness in September seems to have been established during the peaceful Edwardian reign of Edward V11, 1901 – 1910, when England experienced some noteworthy summers, no doubt peaking with the extraordinary heat-wave in 1906, when the early days of September recorded temperatures above 90 F (32 C. ) as far north as Yorkshire. Even the summers of the late 1890’s seemed to prolong themselves far beyond the end of August. In 1895 for example, September recorded 18 days in England when the maximum temperatures exceeded 70 F. (21 C.). Since the middle of the twentieth century we have experienced a disappointing dearth of September heat-waves, although the month did its best in 2011, with 79 F. (26 C.) on September 29 and 30, leading up to the record breaking 81 F. (27 C.) on October 1.

It is worth bearing in mind that the atmosphere and the seas around the British Isles combine their influences at this time of the year to create advantageous appeal for our weather in this stage of the year, although it must be said, that the combined workings of these two elements can also have the completely opposite effect. On the plus side of things, the upper air at high levels is generally warmer than at any other time of the year, something which does help the general atmospheric stability which in turn helps the anticyclones or high pressure systems to persist longer. Another factor arises when September’s anticyclones position themselves to the south or south-west, promoting a gentle south-westerly flow on their northern flanks over the British Isles. Such air-streams travel on long-fetch over ocean waters which are at their annual peak of temperature level, producing cloudy but very warm nights. These conditions, coupled with very dry ground in the wake of droughty summers can give us unusually high minimum temperatures above 61 F. (16 C.). It is an impressive fact that the fall of temperature between sunset and dawn on a short June night is far greater than in September, due to the suppression of radiation from the ground, either by cloudiness or the overall tendency for the vertical temperature gradient between the ground and higher levels is much less steep in September, due to the characteristic subsiding motion of air under high pressure systems. As far as the daytimes are concerned, it is the effects of this warm, subsiding air aloft which prevents the stirring up of the surface air near the ground, and reveals the secret behind those quiet, languid, hazy days when scarcely a breath of wind stirs the leaves on the trees.

The reader may be justified in thinking: this is all very well, but what about the other kind of Septembers, when we are thankful to see that “ all is safely gathered in, ‘ere the winter storms begin? ‘’ I shall be reviewing some of September’s darker weather history later in the month.

PROSPECTS FOR THE WEEK AHEAD

The general theme of August’s weather, featuring high pressure to the south and low pressure to the west of the British Isles is expected to be maintained into September, giving us a fairly typical start to the month. The most likely situation by this weekend will see a large high pressure area over much of Europe, linking back towards Spain, with the North Atlantic developing a successive passage of depressions staying to the west of the U.K and tracking towards Iceland. This pressure pattern will give us southerly or south-westerly air-streams, with brief spells of brisk winds as the associated frontal systems brush past the north-western part of the British Isles.

A good deal of dry and fairly warm weather across our region, with sunny spells and just one or two brief spells of rain on passing fronts. Temperatures maintaining seasonal to warm levels, between 66 – 73 F. (19 – 23 C.), perhaps a little higher on sunnier days. Windy at times, but generally mild nights.