Just Before Dawn

You have the advantage (like South Notts) of not having much high ground to your east, so showers, even on a fairly slack flow, if convection is potent enough, have not much to traverse to penetrate well into Leicestershire - that happened in 96 I seem to remember. The further north you go, the more of a challenge it is to get snow on a slack flow, because you start to get a bit of high ground between you and the sea. Given that the flow on this NAE chart suggests a slightly N of due east direction, it wouldn't surprise me to see the Met O warnings on Sunday for the east coast adjusted south slightly to include parts of Leicestershire and places like Peterborough and N Northants.

Very wise! I think you might be pleasantly surprised on Sunday though.

On my mobile, so can't post the chart at the moment, but NAE ppn charts for overnight Saturday into Sunday quite encouraging with snow penetrating well into the western Pennines by 6am on Sunday morning. *EDIT* Kentish beat me to it!!

Well, setting aside the fact that Lincolnshire is in the East Midlands....... I wouldn't be so sure that showers wouldn't penetrate as far inland as Leicestershire and East Notts on Sunday. The Met O clearly think it's a possibility. Look at their Yellow warning area for snow on Sunday. It includes all of Notts and much of Derbyshire. This is supported by the NAE chart Chris posted above, which is High-res and really the only one worth looking at for the weekend ppn now - that shows snow well into the east mids. Of course, as is always the case with convective showers, it's a bit hit and miss as to who gets them and who doesn't.

Well, there's a chance, which is a start this winter. 18z GFS has a fairly brisk ESE flow by 3pm saturday, so that's good. With showers though, it's always going to be pot luck to a degree.

Stepping aside from the GFS vs ECM/UKMO free-for-all for a moment, and looking back on the 06 GFS Op.... I think it might have been Kold that identified the winter storm progged to cross the country at T+170-T+186 - aside from the storm-force westerlies and heavy rain for the SW (really not what that part of the world needs, given the recent flooding issues), as the system moves out into the North Sea, there's the potential for some petty nasty conditions over the hills of northern England and South central Scotland overnight on the 17th-18th - snowfall over 2000 feet in the Western Lakes, Westmorland, the North Pennines, Cheviots and mountains of central Scotland, with blizzards over the higher routes. We all know the GFS's tendancy to blow up LPs to biblical proportions out in LaLa land, but should the GFS verify, perhaps something to keep a bit of an eye on.

I notice that the NWS are starting to publicise the risk of a low pressure system expected to run NE from East Texas up into the upper Tennessee valley later on on Christmas Day - not just around the risk of snow to the north and west of the centre, but the risk of violent storms and isolated tornadoes in E Mississippi, south and Central Alabama and W Georgia. One to watch later on Christmas day evening.....

It's like watching two punch-drunk 50 year old boxers swinging and missing.

Yep, another dartboard low spawning a second centre further SW than the 18z run, pushing the strongest winds into the Bay of Biscay, though there'll still be gales in The Channel. Looks nasty too. 06 brings it east slightly earlier too. Definately one to watch from your point of view Nick.

GFS is notorious for throwing insane low pressure features around the place outside the reliable (which is about 15 minutes at the moment!!!) but the dartboard low that shuffles along the channel at T+177-ish is out of the top drawer. No doubt it'll be gone on the 00z runs, and even if it's there, I'd expect to see it hugely moderated. At least lets hope so, because as it stands at the minute, it would be driving water in front of it past The Bay of Biscay into the Channel, then pushing it onto shore on the back of hurricane-force winds for 8-12 hours. Then as it moves east, it pulls 60mph+ winds onto the north coast of Devon and Somerset as well as putting down a lot of precipitation exactly where we could do with an extended dry period. Major flooding again for the SW, and potentially a significant coastal flooding risk as far east as East Sussex and western parts of Kent. Still, as I said, hopefully it will have disappeared on the next run.

It probably won't make any difference Pipsta - it's not water that drives convection per se, it's the relative differences in temperature between two air masses. In the UK, that's usually associated with water, but not everywhere. In this scenario, the North Sea is warm enough to heat the air mass close to the surface as the relative difference in temperature between the sea and the air mass travelling over it might be 10-15c, as the air mass close to the surface warms, it rises and the water in it condenses, creating showers. This is probably superficial explanation (someone please put me right)! In the case of flooded land, the water just isn't deep enough to create the disparity of temperature sufficient to heat the lower levels of air to encourage convection to take place. Nor are the areas flooded sufficiently large to start convection generation. Besides which, hopefully, the water levels will have subsided a bit in the next few days.

Late Thursday into Friday looks very tricky especally for The Grampians and Northern Scottish mountains - genuine white-out conditions for a time if the 06z output verified. Less problematic to the south of the Central belt perhaps (except the North York Moors, who's geography is such that it can catch some bad weather even when the flow is slightly west of north) but definately one to watch.

Was Driving through Malton on Friday out towards Helmsley and the watercourses were high already. Given what's already fallen over the weekend and what's due today, I'd think you're spot on there.

A couple of people have PM'ed me asking about rivers rising even as the weather locally dries up, rather than send out lots of PMs, I thought I'd post here. River levels depend on a huge number of factors - the length of the watercourse, drainage basin size (the area of land that the river drains), topography, the nature of the land use in the river catchment, the presence of in-river infrastructure (weirs, culverts etc) and river management activities (vegetation cutting, dredging etc) as well as the type and nature of any flood risk management structures. On short-track rivers in rural, agricultural areas, rivers can rise and fall in hours - our local river tends to peak with 6-8 hours of heavy rain because it's only 30 miles long and uns through a drainage basin of agricultural land with high standards of drainage. Rivers with long courses and very large drainage basins of mixed land use (The Trent, The Severn) can take days to reach peak levels. There are many hundreds of ways that water falling in a catchment can find its way into a water course. The advice is, always pay attention to the Environment Agency Flood Alert status regardless of the weather because weather is only one factor (admittedly a big one!) in river and watercourse risk. This situation is certainly shaping up to be the worst flood event for the UK since 2007, and might even be more widespread geographically.

Hi all - never sure whether Lincs is in East Anglia or the North of England....... The Environment Agency have updated the flood warnings and Alerts for their Anglian region (Lincs, Norfolk, Suffolk, Cambridgeshire, Rutland, Northamptonshire and parts of the Home Counties). As of 23:25, most of the flood warnings were in low-lying areas to the south and centre of the area (The Rivers Nene and Ouse, and Fenland Drains) which suggests that they might not be as concerned about tidal water locking at high tide as they were earlier today (otherwise you'd expect rivers like the Waveney, Welland and Witham to be included). That said, there are 17 flood warnings and 26 flood alerts in place, with flood alerts from the North of Lincolnshire right down to the home counties, so it's worth keeping an eye on the website to be sure. The situation in the SW is looking very serious - 3 severe flood warnings and 63 flood warnings, that gone up by 13 in the last hour.

It's quite concerning how rapidly the situation in the SW is worsening - the number of flood warnings is increasing every 15 minutes - there were 50 at 11pm, when it last updated at 23:25, there were 60.

Three severe flood warnings and 50 flood warnings in the SW at present. With high tide to come, that number is going to rise.

It's worth remembering that even if your local river or stream levels are falling, or at least aren't rising yet, it takes time, often hours and hours before the groundwater gets into river systems - high tides, debris in the watercourse can also be a factor. Best to keep track of the Environment Agency flood warnings just to be on the safe side. http://www.environme...oods/31618.aspx As of 20 minutes ago, there was one severe flood warning, 80 flood warnings and 200 flood alerts in place across England and Wales. High Tide in the SW, SE and East Anglia is between 1-3am, and although the tides aren't especially high, the strength of the on-shore wind (in the SE in particular, depending on where you are) might mean there are some issues with tidal locking of watercourses. I suspect it's going to be a long old night. *EDIT* Two severe flood warnings now, The River Pol in Polperro and the River Cader in Helston.

For anyone interested in following the events live...... http://abclocal.go.com/wabc/livenow?id=8857235 The ABC local affiliate in New York City. Not bad so far, but the usual stuff with some poor junior reporter trying to stand upright on some storm lashed intersection......

National Weather Service has now increased the number of counties under a blizzard warning to include some in Virginia, including the City of Charlottesville.

I think Bill Murray over on Alabama Weather Blog confirmed that Sandy is the deepest hurricane ever to venture north of North Carolina, so I guess it's a locality thing.

Be interesting to see what happens in some of the enclosed bays where the benthic topography is more suited to increased wave amplification - It wouldn't surprise me to see somewhere like the Cape May Peninsula or somewhere on the northern edge of Long Island Sound recording wave heights of 25 feet + at the next high tide - that's pretty sobering.

The Met Office and the Environment Agency have been warning Emergency Planners for a day or two now that this could had the potential to be a significant event. Certainly given the current ground conditions I expect to be busy over the next couple of days. Tide times aren't too bad, but there's a 7m tide progged for later today with an easterly wind at 15-20 mph, we might see a few issues with tidal locking on the later tide tonight on some east coast rivers.

very light snow starting here again too.

Lincoln to Louth was a very interesting drive! A couple of inches here in Louth and readily settling on even the main roads.