Saturday, 29 December 2018

Sudden Stratospheric Warming Underway

It's not been a bad week for December. Last weekend was wet before turning cold for a couple of days but since then it's been dry and mild although not very sunny.
Temperature & Rainfall Records 23-29 December 2018
We needed some fresh veggies for Christmas dinner so we had a trip down to the plot on Monday a cold Christmas Eve afternoon.
It didn't take long to collect some sprouts, leeks, carrots, parsnips and a savoy cabbage. It certainly hadn't been cold enough to freeze any of our vegetables. That might be our entire sprout harvest for the year but the savoy cabbage "Sabrosa" was a pleasant surprise. I didn't really think they'd formed a decent tight head but that wasn't the case.

Later in the week we braved the holiday traffic and had an afternoon trip to the Yorkshire Wildlife Park. Although there was a little bit of sunshine when we arrived around lunchtime, it didn't last very long. I did manage a photo of a lioness making the most of a bit of winter sunshine.
By the time we'd walked around to the polar bear enclosure the sunshine had disappeared leaving a rather dull but mild afternoon.
Yorkshire Wildlife Park
Last Wednesday I posted that the weather models were predicting a Sudden Stratospheric Warming (SSW) event to take place over the North Pole during the Christmas period.
Output from The Tokyo Climate Center
The models were correct and as the chart above shows the temperature over the North Pole has risen dramatically by some 50 degrees Celsius over the last few days. We'll now have to see if this SSW has any effect on our weather. A similar occurrence last year was thought to have resulted in "The Beast From The East" bringing us a cold and snowy late winter and early spring. On the other hand SSW's, as I understand it, have occurred without any dramatic effects on our weather. We may have to wait a few weeks before we know one way or another. 

Tuesday, 25 December 2018

Merry Christmas

Sunday, 23 December 2018

Winter's First Milestone

The winter solstice which took place a couple of days ago marks the official start of winter but to me it marks the first milestone of winter as the daylight hours are now increasing each day. Imperceptible at first, especially on dull winter days like we've been having, but nevertheless daylight hours are getting longer by the day.
Solar Radiation Levels for 21 June & 21 December 2018
As gardeners will be aware light levels have a great deal to do with how plants grow. For comparison purposes the chart above show the solar radiation values for 21 June 2018 and 21 December 2018. Values in summer exceed 1000W/sqm whereas in winter they struggle to reach 100W/sqm. Whilst not a direct comparison of light levels it shows how much less energy we get from sunshine on the shortest and longest days of the year.
Temperature & Rainfall Records 17-23 December 2018
As I mentioned above it's been a dull miserable week, or more, weather wise. We haven't been to the plot for a couple of weeks now but we'll have to fit in a visit to harvest some fresh vegetables for Christmas dinner.
Everywhere is now very wet and soggy so it's going to be a messy job digging up carrots, parsnips and leeks. Still it's probably better than venturing out to the shops at this time of year!

There's been a challenge circulating amongst gardeners on YouTube to answer six questions regarding their gardening year in 2018. If you're interested our answers are covered in the video below.

Wednesday, 19 December 2018

Not Gardening Weather

There's not much going on regarding gardening at the moment but there may well be something afoot weather wise. Over the weekend storm Deirdre came and went producing for us nothing more than an average winter storm. We’d had a few very cold days leading up to the arrival of Deirdre and all the forecasts were that as Deirdre arrived she would bring some snow. As it turned out that wasn’t the case and we just had a wet and miserable day on Saturday.
Temperature & Rainfall Records 13-19 December 2018
The weather talk now has moved on to a major event that the weather models are predicting will take place towards the end of the month. The prediction is that a Sudden Stratospheric Warming will occur in the upper levels of the earth’s atmosphere. Current predictions are for this to occur over Christmas Day or Boxing Day.
From Gav's Weather Videos
The model view is looking down at the north pole in the centre of the image. Normally the pole would be covered with the purple and blue colours indicating extreme cold. The red colours indicate the Sudden Stratospheric Warming predicted to take place.

If this happens it will take several days or even a couple of weeks before it affects our weather and it’s by no means certain that it will have an effect and exactly what it will be.

The last Sudden Stratospheric Warming occurred at the beginning of last year and more than likely resulted in the Beast From The East which brought us a spell of very cold and snowy weather during late winter and early spring 2018. 
02 April 2018
Taking place even earlier this time, it’s possible that we could be in for a very cold January, February and possibly even March. I’ve seen comparisons with winter 2010 which turned out to be one of the coldest winters on record. 

Of course, this is only a weather model prediction so there’s always a chance, that like the snow forecast for last weekend, it won’t actually happen.

Saturday, 15 December 2018

Getting Colder

It's got colder as the week has progressed with Friday turning out to be the coldest day of winter so far with the temperature only making it up to a high of 2.9°C or 37.2°F. For much of the day, the temperature remained below freezing resulting in an average temperature of -0.1°C or 31.8°F, the first time this winter the day's average temperature has been below freezing.
Temperature Records for Friday, 14 December 2018
We only had one visit to the allotment last week. We needed some fresh vegetables and I thought I'd see if I could get some new posts erected for our raspberries. 

The row of raspberry canes is along the boundary between our plot and our neighbours.
The old posts snapped last summer and needed to be replaced ready for this year's canes to be tied into them. The old posts had completely rotted through at soil level and most of the canes were supported by the wires threaded through the posts rather than the posts providing support for the wires.
The ground was fairly soft after the recent rain and the new posts were easily hammered into the ground. Holes were drilled through the posts and the old wire was re-threaded through the new supports.
The raspberries didn't enjoy last summer's hot dry weather and only produced some rather feeble looking canes to carry this year's crop. At least they can be tied to some decent supports.

Saturday, 8 December 2018

Turned Out Wet & Windy

Wednesday turned out to be the wettest day of the week with steady rain all through the daylight hours. In general terms it's been a fairly mild start to the month.
Temperature, High Wind Speed & Rainfall Records for 06-08 December 2018n
We'd been down to the allotment on Tuesday for a few fresh vegetables and the ground was already on the wet side. Our grass paths can get rather slippery through winter. I'm guessing that further rain through the latter part of the week will have made our clayey soil too wet to dig. It's just as well we've done all our main winter digging.
It was a cold and miserable day on Tuesday not a day for messing about on the plot. We harvested some carrots, leeks and parsnips.
Once we'd washed the parsnips and carrots and tidied up the leeks we spent a few minutes making a video of how the plot looks in December.

Since Monday we've had 24mm (0.94in) of rainfall up to mid morning on Saturday, giving us one of the wettest starts to December I've recorded. To add further to the miserable weather it's been blowing a gale since late on Friday night. The gales are forecast to ease in the early hours of Sunday morning. 

Sunday, 2 December 2018

Winter's Here

The first day of December marks the start of meteorological winter. To be honest it seemed like it arrived a couple of weeks ago. Fortunately for us we just managed to get our winter digging done at the allotment and most of our beds are as prepared for spring as we can manage.
We had a very mild last few days to the month which ensured that the average temperature for November was ever so slightly above average at 7.7 C (45.8°F) compared to a recent average of 7.4°C or 45.3°F over the last eight years.
Novembers 2010 - 2018 Average Temperatures and Rainfall 
Rainfall was surprisingly a bit below average considering that we had some precipitation on 23 of the 30 days in the month. It was, without doubt, the dullest November I’ve recorded in 8 years. Although I wouldn’t claim my sunshine records are super accurate due to the positioning of the sensor but the values this year are far lower than any previous years.
Potteric Carr Nature Reserve
Of course as November brings autumn 2018 to a close we can compare this autumn with the previous eight autumns.
 Autumn 2010 - 2018 Average Temperatures and Rainfall 
After a summer that hit the number one position, temperature wise it was a little bit disappointing for autumn to finish a lowly seventh out of nine years. Autumn this year has turned out a little bit wetter than normal so I can't say we've managed to get our winter digging done because of the dry weather.

We've still some jobs to do at the allotment over winter but the weather over the next couple of weeks looks like it's going to remain unsettled with more wet weather to come so it might be that we just make a quick trip or two to the plot to harvest some fresh vegetables rather than get any other jobs done.