https://maltaclouds.net/wp-content/uploads/2018/09/Cu-mediocris-homogenitus.jpg?v=156991994714003065adminhttp://maltaclouds.net/wp-content/uploads/2018/10/logo-1-300x138.pngadmin2017-05-22 18:34:152018-10-30 18:38:23Cu mediocris homo
There was difficulty in classifying the exact cloud formation because the cloud was in an overcast sky with altocumulus opacus.
I opted for cumulus praecipitatio since it was the safest option given the cloud characterics and the fact that no lightning strikes were observed at the time combined with precipitation shaft on the left hand side of this photo. Other possible classifications might have been cumulonimbus murus due to lower extension of the cloud following the national flag of Malta at the centre of the photo or cumulus tuba because of possible funnel formation on the right hand side of the photo.
The same cloud could have been Scattered Cumulus Under Deck (SCUD Cloud) which is accuweather defines as low, ragged and wind-torn cloud fragments, usually not attached to the thunderstorm base. Accuweather also states that such clouds are often seen in association with, and behind, gust fronts. Following the passage of the cloud straight into the area, wind speed picked up considerably reaching wind gusts of 65kmh (Force 8) and also bringing heavy blustery rain, though only for few minutes, following lower wind speeds of Force 6-7 before the approach of the photographed cloud. Such prevailing strong wind would inhibit the funnel cloud from touching the ground to become a tornado. Scud clouds are also differentiated from wall clouds by their relative position with respect to the rain area: scud clouds move away from the rain area while wall clouds maintain the same relative distance. In this case, the alleged scud cloud was caught moving with the cloud cover and not seperate from it in any way hence I give more credence to it being a funnel cloud.
The first thumbnail shows the approaching rain storm (always without thunder) and the second thumbnail shows a solar halo immediately after the shower had passed which normally happens with cirrostratus that is associated with approaching bad weather rather than afterwards. However, more heavy rain showers were going to approach the Islands later in that evening as sea-effect rain showers were affecting the area evident by the visible satellite image on the third thumbnail. The clouds were following the Mistral wind due to an unseasonably cold airmass moving over a still relatively warm sea following 850mb heights of 0C contrasting with surface waters of around 16C. Upon analyzing the weather sounding on the fourth thumbnail, it was noticed that there was some wind speed shear in the lower levels of the atmosphere that could have intiated the funnel cloud but more difficult for a tornado, unless local feautures are involved, in this case strong March sunshine on an unseasonably cold airmass. Broad area of low pressure along with an occluded front was observed on that night via the surface pressure chart on the sixth thumbnail.