Warmth?

[David M]

The forecast today was grossly inaccurate for Swansea. Did anyone else see temperatures exceeding predicted maxima for 9th March?

I believe 17c was reached in some parts of Wales, a full 4c higher than predicted. Must have been similar elsewhere?

[PhilBJohnson]

Hi David,
Near Lincoln where I was, predicted highs of 11c later turned into 13c.
In the wind it certainly didn't feel warm for most of the day but on finding those sheltered south or south west facing banks and hedgrows, it probably was 15 or 16c (very locally) lunchtime to mid afternoon for a short period. By 3:45 I saw no butterflies on the wing where in the same spot an hour earlier, I had to reduce the numbers counted to allow for some being counted more than once. Great to see you were in the right place at the right time !

Kind Regards

[Neil Freeman]

I believe it got up to 16c here in Warwickshire but by the time I got out of work the display on my car was reading 13c and down to 12c when I got home after which it got decidedly cooler as the sun dropped down.
Much cloudier and cooler today.

Cheers,

Neil.

[David M]

I've read that 17.5c was the highest temperature yesterday, and that could well be the case again tomorrow for some of you lucky south-easterners.

Whilst south Wales will be largely cloudy, there is another great opportunity for some to get out and enjoy an unseasonably mild early spring day.

Those who are so blessed should make the most of it.

[bugboy]

I've learnt to take the forecast into account but also use my eye's and look at the sky, something I think the forecasters may forget to do from time to time: case in point the BBC weather app on my phone compared with an actual picture taken at 3pm on Tuesday

It got to about 17 degrees in London apparently on Thursday (can't remember what it was forecast) but it was probably a few degrees warmer than that where I saw my butterflies at work, it's a sheltered hotspot. Looks like similar conditions tomorrow but again I'm at work so I will have to make do with a lunchtime wander

[David M]

Agree entirely, Bugboy. Maxima generally were predicted well below the real, eventual values. This seems to happen every once in a while. It's almost as if the weather services are frightened to tell us the truth.

The differentials, in the south at least, were 2 - 4 degrees out. That's pretty abysmal.

[bugboy]

Agree entirely, Bugboy. Maxima generally were predicted well below the real, eventual values. This seems to happen every once in a while. It's almost as if the weather services are frightened to tell us the truth.

The differentials, in the south at least, were 2 - 4 degrees out. That's pretty abysmal.

On the local forecast this evening for tomorrow 13 was quoted but he said some spots would probably get up to 17. I think they aim lower so the people who don't get the highs don't complain...

[millerd]

I think they err on the side of caution when the weather is like it is at present. It all depends on how strongly the sun comes out, and small differences in cloud cover make for big temperature differences at this time of year. The overall weather situation is pretty clear, but the detail very hard to predict.

Dave

[Padfield]

I interpret predicted temperatures as a kind of base temperature - i.e., the average temperature of the general air mass. If the sun goes in, it is the temperature you will feel before very long, or if there is a strong wind it is the temperature you will feel all the time. When the sun is out, local, still volumes of air can reach much higher temperatures. This effect is probably greater in the Alps than in flatter terrains but I'm sure it must apply to some extent everywhere.

That said, my two main sources of temperature prediction - MétéoSuisse and WeatherPro (= MeteoEarth in terms of sources) always differ. WeatherPro consistently predicts several degrees below MétéoSuisse. For temperature estimates in the field, I use an iPhone thermometer app which locates the nearest real temperature data in space and time and applies an algorithm to estimate the local temperature, adjusting for altitude &c. This generally gives a higher estimate, similar to the MétéoSuisse prediction. Even that, of course, cannot allow for the ultra-local lensing effect of rocky hollows and curving, south-facing slopes. Over the last few years I've become quite skilful at looking at maps and working out where the local hotspots are. It pays dividends in terms of butterflies.

Guy

[David M]

I understand what you're saying, Guy, but these were general temperatures rather than those one could expect to find in isolated micro-climates.

With 12c predicted as the daytime maximum in Swansea, I was surprised to see 14c at all times between noon and 3pm irrespective of where I went (and I travelled widely from east to west - probably 15 miles in radius).

My car thermometer even touched 16c at one point but it never went below 14c that whole time.

[David M]

Just as a continuation of this weather theme, the mid to long range forecast seems to be rather positive. This weekend and next week look set fair with the 30 day forecast also promising good conditions.

Could this be the spring we have been waiting for for several years?

We're already off to an excellent start, and if April proves to be largely dry and sunny, then we could see butterfly numbers rise considerably.

The way things are going, the likes of Green Hairstreak, Small Blue & Duke of Burgundy should all appear in the first third of April.

[millerd]

That sounds rather good, David. I believe the first Green Hairstreaks have already been seen... My worry is that all the nettles, with their growing burden of Tortoiseshell, Peacock, Red Admiral and Comma eggs, are all going to shoot up and be systematically strimmed to ground level by our over-zealous local councils before a caterpillar has hatched.

Dave

[David M]

That sounds rather good, David. I believe the first Green Hairstreaks have already been seen... My worry is that all the nettles, with their growing burden of Tortoiseshell, Peacock, Red Admiral and Comma eggs, are all going to shoot up and be systematically strimmed to ground level by our over-zealous local councils before a caterpillar has hatched.

Perhaps the lack of rainfall might hold this growth back somewhat? Either way, you can normally be sure councils will kill millions of early stage insects in their rather pointless exercise to 'tidy up' the urban green areas.

Someone needs to remind them that nature hates tidyness.

[peterc]

I hope you are right in the forecast for April, David, because for the first 3 months of the year the weather was not too dissimilar to that in 2012 and who can forget what a generally disastrous year it eventually turned out to be for our butterflies. So fingers crossed for at least an average April in 2017

ATB

Peter