COLUMN: Weather Wise with Gordon Currie

January was the tenth consecutive month having above average rainfall. (S)
January was the tenth consecutive month having above average rainfall. (S)
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More weather musings from Gordon as the doors open to the final stage of winter, plus prospects for the week ahead:

Numerous though discomforts be

In depths of winter’s strife,

The poorer those who fail to see

Rewards of farming life –

Foresight notes the early glimpse

Of green upon the thorn,

Fine tuning of the chorus

Of the birds at breaking dawn;

Responsiveness of softer soils

Behind the springtime rain,

Scents of hay ‘neath summer sun,

The hardening of the grain . . .

And in the harsher seasons

We n’er admit defeat, -

With knowledge that security

Is the land beneath our feet!

These conjured thoughts were written many years ago when ploughing the open fields of late winter, under the practical title, February beyond the tractor seat!

The principles within this train of thought are not really so very different today as February opens its seasonal door to the final stages of this winter, which has certainly brought the realities of our weather and its effects upon the land in the crudest way.

Maybe we can all dream in the poignant, benign moments of February’s sunshine, though experience tells us that we should never stray very far from reality – even though the shadows cast by the sunlight across the fields are getting shorter by the day.

February brings to mind some of the old familiars which Robert Louis Stevenson once wrote about,“the belching winter wind, the missile rain and the rare and welcome silence of the snows . . . .” . How true a picture this seems to have been in this year’s preceding month of January.

Looking back on the track records for last month, the statistics for January 2013 reveal some interesting trends. The mean temperature, 37.2F (2.8C) was 2.8F (1.0C) below the long term normal, which illustrates the fact that despite large scale changes from very mild, to very cold and then returning to very mild again, were insufficient to balance normality.

It is worthy of note that four colder-than-average Januarys have been recorded in the last five years, 2009-13. Only January last year came anywhere near normal, with 39.8F (4.3C). The coldest in this group was 2010 with sub-zero 31.7F (-0.1C).

We certainly have moved away from the very comfortable phase of warmer-than-average Januarys that we enjoyed prior to 2009.

In the 11 years between 1998 – 2008, ten Januarys were warmer than average, some remarkably so, peaking at 42.9F (6.0C) in 2005, and 42.2F (5.6C) in 2007.

Examining the rainfall figures for January this year, a total of 60.3mm (2.41in) compares with the long period average of 50mm (2in) which makes it the tenth consecutive month having monthly rainfall above average.

If we look through January’s local rainfall history on my records, it appears to be one of the most inconsistent months of the year, featuring wide variations. Two of our wettest Januaries have occurred in the past decade, with 100.4mm. (4.01in) in 2007 and 146.5mm (5.86in) in 2008. In complete contrast, one of the driest Januarys was 2006, with 15.8mm (0.63in).

Reviewing the daily changes of weather through last month, the year began with the most ideal westerly pressure pattern that any winter season has to offer – high pressure over France, expanding northwards and bringing the air-mass trajectory from the sub-tropical Atlantic beyond the Azores.

Temperatures responded, with the mildest days of the month being 3rd and 4th, 52-53F (11C), with the mildest nights, 48F (9C) on the 2nd-3rd, and 3rd-4th. Throughout the first nine days, light westerlies brought broken clouds, sunny spells and some magnificent sunsets. Some days were magnificently sunny, with wispy cirrus clouds, such as the 9th. Only four days with slight rainfall, totalled merely 5mm (0.20in).

Our reverie of mildness was soon to be interrupted, when, on the 11th, our region was confronted with two separate weather fronts, one lying north-south down the spine of the Pennines inclined to move eastwards, the other, just off the east coast of Yorkshire, trying to push westwards, with very cold air from the Baltic region coming in behind.

Our mildness waned by the 12th, as very cold continental air gained ground, leading to quite an intense period of freezing temperatures and snowfalls, especially between the 15th - 18th, when maxima remained below freezing, between 29 - 31F (-1 to -1.5C) on the 16th, 17th and 18th.

Total snowfalls between the 14th and 22nd amounted to 25mm (1in) in terms of rainfall, but our region was protected on some days, notably the 21st, by a snow-shadow due to the topography of our region in relation to the North Yorkshire Moor shelf.

With a direct easterly wind, our area is shielded from the snow-laden easterlies in exactly the same way as the Pennines creates our familiar rain-shadow of the westerlies. Milder conditions, bringing extreme atmospheric volatility from the Atlantic, restored our temperatures back to 54F (12C) by the 29th, with minima up to 45F (7C) by the final morning of the month.

PROSPECTS FOR THE WEEK AHEAD

Last Saturday’s brief snap of northerly winds may prove to be the sounding board for the second week of February.

Another plunge of Arctic northerlies in the current week will force in-coming Atlantic fronts to be steered in a north-west-south-eastward movement over the British Isles.

At the same time, pressure is liable to rise again to the east, giving rise to a possible east-west battleground of air-masses – very typical of mid-February.

Staying mainly cold and rather wintry at times, with occasional showers of sleet or snow, especially towards the North York Moors.

Sunny interludes on most days, but day temperatures generally below normal, 39-43F (4- 6C). Sharp frosts, especially around the weekend period, down to 23F (-5C), with northerly winds.