Reigate was one of the warmest places in the UK today. The town bathed in air from North Africa at nearly 20ºC. The strong SW wind driven by a 100mph jetstream aloft along a decaying front brought some superb mid and high level clouds across Reigate. A variety of unusual clouds were visible.
Cirrocumulus is a high level cloud and unusually covered much of the sky from early on this morning. The light dappled mini-cumulus flecks 30,000 feet in the sky were beautifully fibrous in appearance. Occasionally the cirrus rolled into parallel lines converging on the horizon: cirrus radiatus.
Virga is another unusual site for cloud spotters. These are ice crystals falling from cirrus or altocumulus: this precipitation evaporates before reaching the ground so appears as a tail streaking out from underneath cirrus or altocumulus. Several virga could be seen during the day but tend to disappear quite quickly.
Unusual altocumulus lenticularis wave clouds rolled in at the end of the day on a decaying front and even deposited a few drops of rain momentarily. Virga making it to the planet surface! Altocumulus lenticularis are the clouds occasionally mistaken for UFO’s! They are usually formed by high winds blowing over hills or mountains and creating wave like clouds in the air stream; our lack of high mountains makes them rather rare in the SE.
Although not as warm as today, mild and breezy conditions will persist for many days now. It will not always be dry but less than 10mm of rain is forecast for Reigate over the next 8 days so any fronts reaching us will be weak.
The pressure pattern and direction of our weather will be the “reverse” of those cold days of March: south westerly and westerly winds from the Atlantic will prevail most of the time over the next few weeks. LOW pressure systems are set to cross to the north of the UK and HIGH pressure will sit to the south: this will keep the jetstream more or less persistently over the UK and drag in milder but moist air, especially for the west. Reigate and the east of the UK will be drier and can expect daytime temps around 15C, cooling towards the end of this week.