Strong Bora on the Croatian coast

Strong Bora on the Croatian coast

06 March 2015 12:00–13:00 UTC

Strong Bora on the Croatian coast
Strong Bora on the Croatian coast

Very strong episode of Bora wind occurred over the eastern Adriatic sea, on some parts of the Croatian coast it reached speeds of 200 km/h.

Last Updated

22 October 2020

Published on

06 March 2015

A secondary low pressure system that formed in the Adriatic Sea, connected to the passage of the cold front from the north, was responsible for the synoptic setup favourable for a north-easterly flow in the coastal regions of Croatia.

by Ivan Smiljanic (DHMZ )

 High Resolution Visible overlaid with geopotential at the pressure level 300 hPa
Figure 1: High Resolution Visible overlaid with geopotential at the pressure level 300 hPa
Full resolution

A strong gradient between the cyclone and high pressure over western Europe further enhanced this flow. This can be seen in the HRV, Meteosat-10, 6 March 12:00 UTC, overlaid with geopotential at the pressure level 300 hPa (Figure 1).

Stau clouds on the eastern side of the Italian Peninsula and the cloud-free western coast of Italy can also be seen.

 
 Visible image with the low level model winds overlaid
Figure 2: Visible image with the low level model winds overlaid
Full resolution

The visible image from 6 March 12:00 UTC with the low level model winds overlaid (Figure 2), reveals the main direction of the predominant flow over the Croatian coast. This is actually an inflection point between anticyclonic synoptic scale movement north-west of it and cyclonic movement south-east of it.

 
 MODIS True Color RGB, 06 March 12:20 UTC
Figure 3: MODIS True Color RGB, 06 March 12:20 UTC
Full resolution

The quarter kilometre resolution MODIS True Colour RGB image (Figure 3) shows the backscattering contribution of sea spray and the white caps of the high waves, which appear as a bright signal over highly absorbing water surface (marked in red).

 
 Natural Colour 06 March 13:00 UTC
Figure 4: Natural Colour 06 March 13:00 UTC
Full resolution

The Natural Colour RGB image, 13:00 UTC, (Figure 4), shows snow on the high grounds of the Apennine, Alpine and Dinaric Alpine mountains. Note that in this RGB the snow has the similar cyan colour as high cirrus clouds.

 

Heavy rain episodes were also detected, specially in the south parts of the Croatian coast. The meteorological station in Dubrovnik measured 190 mm/m2 in less than 24 hours.

 
 

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