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#stormConor was Cat 1 Hurricane over Faroes on Christmas Day

You may have missed him, but #stormConor was a fighting wee monster as he passed through Thorshavn (Faroes) on Christmas Day.


The 4pm SYNOP for Thorshavn WMO station 06011 read as follows:

Air Temp: 4.0C Dewpoint: 1.4C Pressure: 966.6hPa Wind dir: NW Mean speed: 72kts (Hurricane Force 12), gusting 102kts (117mph)

and again at 6pm:

Wind gust: 102kts (117mph)

That's several mph stronger than the Stornoway 03026 Hurricane of January 2015. Thorshavn 06011 also recorded 4 consecutive days from 23rd-26th of wind gusts exceeding 95mph (and 3 consecutive days of over 100mph).

The satellite animation above (courtesy of sat24, images copyright METEOSAT)  shows that Conor was a classic Shapiro-Keyser low, with a probable #stingjet being the reason for the exceptional wind speeds (Shapiro-Keyser 1990). Further evidence for the stratospheric intrusion of very dry air (usually found in the region of a tropopause lowering with a #stingjet) can be seen in the following METEOSAT 6.7µm water vapour channel image for 12h (below).  A prominent dark area (dry intrusion) lies directly east of the cloud head tip, and also west of the main frontal boundary:


This dry air arrived in Stornoway during the evening of Christmas Day. A dewpoint of -6.4C was recorded at 18h with a relative humidity of only 45% (due to the 'ice-bulb' effect, the ground was freezing despite an ambient air temperature of +5.5C). The NAVGEM global met model also indicated that widespread tropopause lowering was taking place near #StormConor (red blotches on following chart):


@eddy_weather, Stornoway, 29/12/2016


Shapiro, M.A. and Keyser, D.A., 1990. Fronts, jet streams, and the tropopause. US Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Wave Propagation Laboratory.