I can always tell when my work / life balance gets really out of kilter by the number of unread issues of New Scientist on my desk. Currently it stands at 4 weeks worth, so something is definitely wrong :), hence the delay in posting this update…
Onto the weather and we have a recurring weather pattern for this week and next. If you look at the above graphic, note the shape and pattern of the weather systems for Monday – 5th December and Wednesday 14th December, they’re very similar.
General Weather Situation
As predicted last week (smart arse award), we’re currently in the grip of a very cold low pressure system that’s pulling in strong westerly wind and moisture. In Scotland and the North of England, this is falling as snow, further south, as rain. One normally associates a westerly wind with mild temperatures, but that’s not the case at present and you can see why from the rolling graphic above, those winds originate over Iceland, so are polar in nature..(read very cold)…As we go through the early part of this week, the pattern is fixed with strong, biting cold, westerly winds, plenty of heavy showers, some of these turning wintry, right down to the Midlands. These showers will fall late on Monday, throughout Tuesday and Wednesday and since they’re coming from the west, they’ll reach Ireland first, so take 8-12 hours off those timings if you’re there…Late on Wednesday, a wave of mild air pushes through, just like last week and temperatures will pick up markedly on Thursday. The wind will still be westerly, but much milder and they’ll be rain associated with this mild front, heavy for Munster later on Wednesday and then pushing east into the rest of the U.K for Thursday, again falling heavier over the higher ground in the South-West, Wales and North-West England.
A North-South temperature divide will develop as the North of England and Scotland stays in the grip of the cold low, whilst from the Midland’s south, it warms up with that mild rain. Thursday will dry up p.m and Friday looks to start mainly dry, but a little cooler, particularly in the evening.. By Friday p.m, a new rain front reaches Ireland, this again pushes eastwards on a westerly air stream to affect all areas over Friday night and Saturday morning, clearing later in the day to leave a dry Sunday, before the next rain front marches in…
Next week looks to start off windy, wet, but mild, before a new polar low begins to exert its influence by mid-week and we start the pattern again. That is to say, cold westerly winds, wintry showers in Scotland and the North of England, perhaps reaching further south to The Midlands by the end of the week. Yet again though we have that protective, Atlantic high pressure system sitting below this arctic low pressure and preventing it from really moving south, so at present I can see us running back into mild weather for the weekend before Christmas, but it’ll only need to shift south and we’ll have snow, so keep those sledges handy 🙂
Soil temperatures have just dropped away over the last week or so and there endeth a very busy month growth-wise !. You can see from the graph below that in November 2010, growth stopped around the 9th of November, but in 2011, the corresponding temperature point occurred on the 28th of November, nearly three weeks later. Looking at growth potential in growth-degree-days, there was 163% more growth in November 2011 vs. 2010, so that explains the extra labour and diesel requirement for the month, not to mention the extra disease pressure….
Disease pressure has also declined with the cold temperatures of the last 5 days or so, but expect it to make a slight surge towards the end of this week, so be on your guard. Personally, I think if you have kept Fusarium populations low up till now, the chance of getting hit with a bad disease outbreak is much, much lower. On this note, I’ll be giving a Christmas forecast with a specific ‘heads up’ on spray days this time next week. That said, with the current pattern of deep, low pressure systems, that means high winds and tricky spraying conditions, but we’ll see closer to the time.
Plenty of worm activity around at the moment with the arrival of some rain and I expect this to continue for the next week or so particularly since it’s likely that the rain on Thursday will increase the soil temperature again, as it will fall at 10°C or thereabouts. Still can’t complain, we need every drop of the stuff at the moment…
All the best