Ex-Maria And Her Effect On Next WeekAdded : Saturday at 13:27 A commonly known weakness of the numerical model output is the handling of ex-tropical systems when they cross the North Atlantic and interact with the jet stream. This weekend is no different and even now there is a still a fair amount of uncertainty relating to the remnants of ex-hurricane Maria on Monday and this is impacting the outlook for the rest of next week.
Although there is good agreement on these remnants weakening as they approach the UK courtesy of an upper ridge, there is still divergence over where the rain associated with this system falls and this will be the difference between a wet or dry Monday for southern counties of England.
This morning's 00z GFS ► run brought rain across many southern counties of England on Monday, but the 06z run now keeps most of the rain over the English Channel:
Let's have a look at the higher resolution Arpege model for later on Monday:
Not too dissimilar to the 06z GFS ► run so it's beginning to look like this is the more favoured outcome, but we will need to check what the output later today is showing to see if the models are now getting to grips with the pattern once and for all.
This chopping and changing all has a knock on effect. The 00z GFS ► which took the rain further north then went on to show this by the middle of the week:
High pressure to the south helping to draw up mild south-westerlies for the second half of the week.
However here is the 6z GFS ► output for the same time, and remember, it takes Monday's rain further south:
This brings the 06z GFS ► more in line with the 00z ECMWF ► output which showed a changeable and cooler second half of the week:
What did the 00z ECMWF ► do with Monday's rain? It kept it south. So if you want a warmer end to next week you want to see Monday's rain heading north but this is starting to look like the unlikely outcome.
METEOROLOGIST: BARBER |