Temperatures across England are already widely 2 or 3°C warmer than they were at the same time yesterday (fig 1), and a new record warmest 7th of May looks a possibility, although the previous record, according to the TORRO website of 29.0°C set in 1976, will take some licking. The warmest temperature at 10 UTC today (fig 2) look to be further east than they were yesterday, although if anything the easterly gradient is weaker than it was over London and the southeast.
Provisionally, yesterday the 6th of May was the 2nd warmest since 1878 in Central England with a maximum of 22.8°C, which was over 8°C above the 1961-1990 long-term average for that day (fig 1). Today’s maximum temperature is on course to beat the previous highest for the 7th of May set in 1976 of 23.3°C, with temperatures at 09 UTC already much higher than at the same time yesterday.
The sea fog that’s been lurking around the coast of southwest England for the last three days continues to affect the coastline of north Cornwall and Devon this morning. If anything it seems to have lifted into a more organised thicker band of low stratus rather than the sea fog of previous days, with no ship tracks visible in it today as there were yesterday.
There’s a lot of talk at the moment about the possibilities of tomorrows Bank Holiday being the warmest on record. Call me an old stick-in-the-mud traditionalist if you want, but I like to think of the early May bank holiday as being linked to the pagan holiday of May Day, which tradition has it falls on the very first day of the month for some obscure reason, and not the first Monday as it does now. I could write some code to list the warmest, but to hell with that, I thought it was much quicker just to look at warmest May Day’s rather than the warmest Bank Holiday which flits around from year to year. Anyway looking at maximum temperature in Central England it looks like the warmest since 1878 was back in 1966 with a temperature of 23.7°C which was almost 10.2°C above the 1961-1990 long-term average (fig 1).
The synoptic situation back in 1966 was not that different from the one at the moment (6th May 2018), with high pressure to the east and a col over western areas (fig 2). Why back then in SYNOP reports we rounded temperatures to the nearest whole degree and reported pressure to tenths of millibars now looks rather odd, even allowing for low power communication speeds with Baud rates of less than 9600 (fig 3).
Looking back at the warmest May Day mean temperature since 1878 in Central England, 1990 and 2005 with 16.1°C tie for the honours for that (figs 4 & 5).
Some good ship tracks in the sea fog visible in the latest satellite images of the Irish and Celtic sea this morning (fig 1), well they certainly look like ship tracks to me, even if R S Scorer thought that there were a rare phenomenon back in 1967. Perhaps the increase in size of these massive ULCV container carrying ships has something to do with it? Any light breeze hitting the side of one of these monster ships (fig 2) could only really go up I would have thought, and carve some kind of furrow though the fog.
In a midday visual satellite image from NASA (fig 2), it appears that the Holyhead to Dublin ferry may have left a ship trail, although it looks like it may have drifted a little in what breeze there is across the Irish Sea (fig 3 & 4)
The models captured the development of the low called Pearl very well as it deepened and tracked E’NE, and it’s all set to spoil the rest of the weekend with its rain and cloud especially across the southeast of the country. The low almost seems to be developing a black pearl like centre as it spirals round just southwest of the Scillies but that’s probably my over active imagination (fig 1).
Estimated rainfall totals since 18 UTC yesterday are starting to mount up across the southwest, with the first lime green pixels appearing over the Lizard and Bodmin moor (32-40 mm), I’m not sure whats wrong with the radar across the Celtic Sea though (fig 2).
It seems to me to be a tale of two lows, tonight’s rather interestingly, some may say bizarrely, hasn’t attracted any warnings for heavy rain so far from the Met Office (fig 1), but they have already issued an early warning for the possibilities of heavy rain for the low that will affect southeast England later on Sunday. Depending on what NWP model you look at the accumulations for Friday don’t look particularly that heavy (fig 2), but I wouldn’t have thought it would have hurt to have issued a blanket yellow warning for southern and central areas for 15 to 25 mm locally 40 mm, but what do I know. I suppose they still have time to do it but it’s cutting it a bit fine.
Good old David Braine, we’ve had more showers first thing this morning (fig 1) than we saw all day yesterday!
Hopefully I can get the washing hung out by the end of the morning as the showers finally die out and the upper cloud from low Pearl rushes in this afternoon. I guessed at the central pressure of 1016 hPa, but I can see that the pressure has just started to fall at weather buoy ‘Pap’ so Pearl has engaged the jet stream (fig 2).
It’s interesting to see how the three main NWP models handle tomorrows low and the heavy rain it introduces across the country (fig 1). The Met Office take the main thrust of the rain north into Ireland, whilst the GFS and the ECMWF are in no doubt that the action will be centred much further east over southwest Wales. I think the UKMO model looks out of step with the other models on this one, time will tell.
One of the tricks of the trade as a weather presenter when you want to be as vague as possible about the timing of rainfall events like this, is to leave of the exact time in the graphics, so it’s good to see that Aidan McGivern has picked this one up and is now ready to move on to the next chapter (fig 2).
As well as this cyclonic development on Friday another low threatens to spoil the weather in the southeast of England during Sunday. It’s amazing just how the weather likes to dish out bad weather in as fair a manner as possible isn’t it?