Good morning everyone and a very Happy New Year to you all. Here is my 1st report of 2014 taken using the midnight outputs from NWP for today Wednesday January 1st 2014.
All models remain very unified in stating that the current unsettled spell will continue for at least the next 7 days with Low pressure areas continuing to crash across the Atlantic up to the NW of Britain. This maintains the feed of strong to gale and locally severe gale force SW winds at times along with areas of rain and showers repeatedly crossing quickly NE or East in the flow. The rain will be persistent and troublesome at times giving rise to surface flooding issues almost anywhere but more likely to the usual prone locations. In the showery interludes the usual winter cocktail of hail, thunder, sleet and snow is just about possible particularly near Western and Southern coasts with only very short windows of drier weather in between.
GFS then takes us through the middle and end of next week with some moderation in the wet and windy regime for a time as isobars open out with somewhat colder air in tow for a time. However, on this morning's operational run it isn't long before renewed Atlantic gales and heavy rain sweeps back in off a volatile Atlantic for the remainder of the period to maintain the pattern that we have grown so used to since mid December with little chance of wintry weather.
The GFS Ensembles back up this theme very well with a heavy bias towards Westerly winds being maintained and heavy rain at times throughout the period with temperatures never far from average overall.
UKMO today shows a deep depression near 950mbs between Scotland and Iceland next Tuesday which means a continuation of strong WSW winds and showers at least and most likely some longer spells of heavy rain in places too with temperatures close to the January average.
GEM shows this feature filling in situ as we move through the middle and end of next week with the rain and showers dying out slowly before High pressure building to the SE sets up a milder SW flow with rain for the North and West to end next week.
NAVGEM also shows this feature filling up to the NW over the middle of next week but insufficiently to change the weather pattern of rain or showers within the confines of the run this morning.
ECM is looking very isolated in it's prediction of a pattern change later next week and carries on from where it left off last night developing it further into a Scandinavian High pressure by the end of the week coupled with a tongue of cold air wafting gently West towards Southern Britain in slack conditions. There would continue to be a risk of rain from this slack pressure zone across the South perhaps turning wintry over the hills.
The ECM Ensembles Mean chart for 10 days does not support the operational ending up looking more like GEM in 10 days time with High pressure biased towards being to the SE of the UK and the rampant Atlantic set to pounce once more. However, I realise this is just half of the picture and there will no doubt be some support for the operational in among the gloom of the other members of it's set.
http://www.wetterzentrale.de/pics/Reem2401.gif
The GFS Jet Stream forecast suggests the flow maintains it's current trajectory for some while yet with only minor tweaks and adjustments North and South over the UK in the forecast period.
In Summary today there is a split in the output theory on developments following the filling of a large depression North of the UK towards the middle of next week. While much output doesn't stretch out far enough to evolve it on it looks unlikely that GEM or NAVGEM would follow any other route than that of GFS which maintains a strong Atlantic flow with deep depressions continuing to rattle over the Atlantic with all the wind and rain to which we have become accustomed maintained well into mid January. However, ECM has other ideas with a block forming over Scandinavia and with Low pressure West of Iberia and over Eastern Europe the block could be supported at this Northern latitude without collapse. The Day 10 chart is quite a clever chart as it leaves you wanting it to move on a few more days as there is certainly a chance of something better for cold fans to grasp hold of today. The main problem however, is the Ensemble mean chart for day 10 puts a bias towards High pressure to the SE of Britain whilst drier would hardly lead into something notably cold. More runs needed and greater cross model support too.
Transcript taken from Norton-Radstock weather Website
Martin G
Kilmersdon Radstock Bath Somerset