Rapid cyclogenesis in action!

Low Carola is deepening very quickly at the moment, and the curl of cloud she is spinning up makes an impressive site in the latest satellite imagery to the southwest of Ireland (fig 1), as do the plotted observations and barograph from the weather buoy 62029 better known as ‘K1’ (figs 2 & 3). As far as I can see Carola easily breaks the barrier for rapid cyclogenesis of 24 hPa in 24 hours, the pressure there has fallen by 37.4 hPa in 12 hours, in fact I don’t think I have ever seen sustained pressure falls like that on a chart from an extra tropical low. No doubt […]

13/14 August 1979 – The Fastnet storm

During Monday the 13th of August 1979 a depression named low ‘Y’ intensified and tracked quickly east across the eastern Atlantic. At midnight on Tuesday the 14th the low was close to Valentia Island in SW Ireland, with a minimum central pressure of around 979 hPa, making it one of the most intense lows for any August. The chart above (fig 1) is plotted from archived SYNOP observations that I’ve collected and also includes a background pressure field from the NCEP reanalysis project to fill in any gaps. The storm caught out the competitors in the Fastnet race and out of the 303 starters, only 86 finished. The Wikipedia article states […]

Extreme Cyclogenesis

All this talk of named storms and weather bombs in recent years, got me thinking about extreme cyclogenesis and the greatest pressure falls and rises that I could remember. As an observer it was almost a badge of honour, that if while you were on shift as the duty observer, you reported a three-hour pressure change of greater than 10 millibars in a three-hour period, which in my experience happens more rarely than you might think. Even when plotting a chart, you would always take a little more interest if you came across an observation with a tendency of 10 millibars or more. So back to what I think […]