As the title suggests, it looks like the blocking event that has seen us through most of November with mild and dry conditions is going to invert. This means we move from sitting under a peak of warm air to sitting under a trough of arctic air. Note the weather patterns below and the gradual movement away of the continental high that has log-jammed our weather through October and November. This allows cold arctic air to flood down and form a deep trough with a resident, non-moving, low pressure at its heart. If this scenario transpires, it’ll bring moist cold air down from Iceland and potentially the first snowfalls of the winter, particularly for Scotland and the north of the U.K for the end of November, but it may extend further south than that. Remember, this projection is 10 days away and alot can change in that time. That said, as it stands it looks to me like a dead ringer for the end of November 2010.
General Weather Situation
For the start of this week we have a very recognisable scenario, that of a low pressure system with rain approaching the U.K from the west. As it does so, it butts up against the continental high which pushes the rain across Ireland and the west / north of the U.K and leaves the south and east dry. So dry is it here in the Midlands that Anglian Water applied for a drought order last week because of the lack of autumn rain, bizarre, a drought order in November. Now it’s the end of this week that is going to be critical, because if that high pressure moves away, this will allow the low to affect all of the U.K, so cooler and wetter and as hinted above, the start of winter will potentially be upon us soon after.
For Monday, we have the first rain front into Kerry and the South-West of England, Wales and that rain will push north and eastwards across Ireland and into the west of the U.K, but I don’t think it’ll reach the Midlands or South / South-East. That rain front will hang around the west of England, Wales on Tuesday, clearing Ireland and may even give some showers inland, but I don’t expect much. Temperatures will remain mild, with a south to south-westerly wind, so low teens during the day and high single figures at night, provided we keep cloud cover. By Wednesday, more rain reaches Ireland and this pushes into North England, Scotland through Thursday, intensifying to heavy rain by the end of the day. Friday is the critical day in my mind, because currently the forecasts suggest rain pushing in from the west to affect all of the U.K during the day and if this is the case, it signals the demise of the continental high and at the very least a change in the weather pattern going forward from the end of November. You’ll notice at the weekend if this change takes place because firstly it get wetter and secondly it’ll get cooler as the wind changes round to the north.
As discussed above, this really hinges on the movement of that continental high pressure because the projection is for heavy rain to push into the South of England and the Midlands on Saturday and this is then set to be followed by more heavy rain for the start of next week, (w/c 28th Nov) with a change in the wind direction on Saturday to more northerly-north-westerly. Not all projections agree about this, so it’ll be interesting to see who’s right.
If you’re wondering why you have so much disease on higher-height of cut areas, take a look at the picture above, showing both condensed dew and guttation fluid (droplets on the leaf tip) at 3 p.m in the afternoon (I live an exciting life eh?). High atmospheric moisture is currently providing 24-hour, leaf wetness, in other words great conditions for Fusarium. That said, there’s a bit of everything around at present with lots of fungal activity, plenty of mushrooms and active Fairy Ring.
Fusarium activity will begin to decrease, if we get the predicted drop in temperatures, as will growth, and at least we have some clear lessons learnt from previous years about how to condition our turf prior to the onset of winter.
The bottom line is this (in my humble opinion) ;
Turf that goes into the winter healthy, with adequate nutrition in the leaf will emerge healthy. Turf that is either impoverished or excessively lush, due to low / high autumn nitrogen applications respectively, will have a much higher chance of suffering from disease. The same rule applies with respect to Fusarium, in that a clean sward with low fungal inoculation levels will stand a very high chance of coming out of the winter in the same state and that’s why it’s so important to keep disease populations at bay / under control through October and November.
So I’d suggest getting some good cuts into higher-height of cut areas this week if conditions allow and maintaining good plant health using the tips I’ve discussed in previous blogs. Spray days should be ok for the first half of the week, (for the central and south of the U.K anyway) but as the wind increases in the 2nd half of the week, it’ll get trickier.
All the best..