High Pressure Muscles InAdded : Monday at 11:32 It's that time of the year when lots of changes start to take place across the Northern Hemisphere. Much of this is driven by the large temperature contrasts between land and sea. At the moment, we have the seas and oceans rather near their warmest for the time of year, but we also have the cooling land plateaus in the ever decreasing amounts of daylight.
This is the current chart :-
You can see low pressure to the Southwest of Iceland and a high pressure system to the South of the UK.
Over the next few days, the situation doesn't actually change a great deal. By Wednesday we have this :-
Low pressure still in control to the Northwest of us and high pressure expanding to the South. Also, you'll see the low pressure area to the West of Portugal which is trying to bring milder air North for a time.
By Thursday we have this :-
This mid-Atlantic high pressure area is en route to Europe and sort of climbs over the top of the low in the Atlantic and joins up with the European high. The result, is that for next weekend the GFS ► settles an area of high pressure over or near the UK :-
Most of the global models seem to struggle with these weak ridges which build in. They tend to keep them slightly too far West in the medium range of the forecasts and allow cooler air to come in from the North, but the closer the forecast gets, the more you'll see the ridge holding on slightly more than they expected.
The GFS ► as the ECMWF ► go for the ridge to break at some point either later in the weekend or into next week, but still low confidence in this happening as it's just one of those things which numerical models seem to get over-itchy about during the late Autumn and early winter synoptic patterns.
METEOROLOGIST : MARSH |