You might be thinking it’s been quite a snowy end to 2017 wherever you live in the country, but spare a thought for those of us down here in the southwest who so far have yet to see a snowflake. In Cornwall none of the SYNOP stations have reported an air frost so far this Autumn, and even here in mid-Devon although we have had four air frosts, and only one of these was for a temperature lower than -0.2°C.
I’d like to do a similar thing with snow that I do with frost, by checking for the occurrences of snow in the present weather from the hourly SYNOP files. Not only would that mean opening thousands of hourly SYNOP files, but many of the AWS reports either don’t report a present weather, or if they do they’re not that reliable when it comes to the reporting of freezing precipitation. The same thing applies to the reporting of thunderstorms, I have yet to see an AWS report a thunderstorm, even though I know the more sophisticated Vaisala systems are capable of sensing them.
It looks a bit cold on top of the Brocken mountain in Germany this morning (fig 1). At 09 UTC the temperature was -1.3°C and the wind was still meaning 23 knots (Jag windchill -9.3°C). It’s not a particularly high mountain at 1142 M, and not that dissimilar to Cairngorm at 1245 M, although wind speeds never get quite as severe as they do in Scotland, the weather can still get pretty cold and stormy at times, as the plot grid for the last 24 hours shows (fig 2).
Overnight saw the first real frost of Autumn in places, particularly across parts of Scotland and the Borders, with temperatures falling as low as -5.0°C at Tulloch Bridge in Highland. The easterly never let up all night in Devon and kept things above freezing, as it did across most of eastern England.
It strikes me as strange that when the Met Office need to justify a named storm or a yellow or amber warning that they’ve issued for strong wind, how they can seemingly pluck observing sites out of thin air, some of which you might never have heard of before, such as:
Berry Head, Devon
High Bradfield, South Yorkshire
Needles Old Battery, Isle of Wight
Orlock Head, County Down
Salsburgh, North Lanarkshire
But when the winds have been a little stronger than they forecast, as was the case today with storm Brian, they seem to be able to exclude some stations from the graphics they generate (fig 2) as if the offending station didn’t even exist. In fact the winds are higher in western coastal districts of Wales than anywhere in Ireland, the difference is that Met Éireann did issue an amber warning for gusts to 80 mph, and the Met Office didn’t. I would like to use observational data from these sites myself, but I can’t access them, the reason being that they don’t have a WMO number, and don’t report a regular SYNOP observation, more’s the pity.
Two spiralling extratropical storms in one week as dangerous Brian moves in off the Atlantic. I notice that the pressure at 62095 (‘0’ marks the position of weather buoy 62095 in figure 1, and the inset plot grid in figure 2), which is just to the north of Brian, has started to bottom out at 975.9 hPa, but Brian will continue to deepen to 964 hPa by midnight according to the forecast chart from the Met Office. I notice that the wave height being reported from the weather buoy 62442 at 49° north are already 9.2 metres (30 feet), and the wind there has veered westerly gale force 9.
It’s quite unusual for a wind group to go missing from a WMO block #03 synop report like it has for the last two hours for Valentia (#03953). Perhaps the met technicians are down there from Dublin, checking it out to make sure it’ll stand up to the pummeling Ophelia will give it on Monday? The rest of the report from the AWS is all there, but minus the wind direction (fig 1). I’m sure it’ll all be up and running for Monday, well at least I hope it is.
I think the plotted observation in the 07 UTC chart, southwest of the Fastnet Rock from EUCDEO is from a ship and not a weather buoy, and which looks like it’s making for port in Ireland before Ophelia makes an entrance.
I see that Hurricane Maria is now getting very close to weather buoy 42060 at 12 UTC, it will be interesting to see just how the buoy gets on. Judging by the wind direction at 12 UTC, the hurricane is not far to the E’SE of the buoys position.