BERTHA in North Atlantic

Disturbance fourteen is now approaching the Yucatan channel and headed slightly north of west at 12 knots. This is still little more than a wave of low pressure rather than anything with a spin to it, and has a field of showers and thunderstorms in tow, which it will bring to the southern US gulf over the coming weekend. Development is not anticipated.

Disturbance sixteen is following the trail - and mirrors the characterises of - fourteen. Twelve hours steaming into the Eastern Caribbean, disturbance sixteen is a weak tropical wave, making around 13 knots on a course slightly north of west. Development is not expected. Enhanced showers and storms are likely to continue in association with this tropical wave as it moves west to west-nor'west through the Caribbean.

Whilst the North Atlantic is a long way from our normal area of interest, we are being asked for an update of ex-hurricane BERTHA. This extra-tropical system is weakening and wobbling as it closes on north west Europe. This has had an eye on the west coast of the UK for the last 48 hours, but the storm's path has since changed and it is now heading for northern France. What rotten luck.

Returning to tropical latitudes, we commented yesterday on the dry Saharan air belt across the eastern half of the convergence zone. Shifting wind directions give an early indication that this could shift in seven to ten days, opening up the storm conveyor belt towards the end of the month.

Storm cones aloft in France then. Otherwise, stand easy.