Sunday 4th November - Active Weather System

[ZONE 51]

The weather system is developing and starting to move into SW UK as i type with heavy rainfall setting in now, this system developing into a small but potentially potent low pressure is going to move quickly across Southern England through the early hours of Sunday and throughout Sunday.

NAE and GFS bring a large area of heavy rainfall across Southern areas, some of this rainfall causing flooding, the air is cold at the surface and upper temperatures are reasonable for wet hill snow, and even a risk sleet at lower levels in places, although that risk is low.

Another element of this system is the winds, there is likely to be strong gusts as the low moves across, with the south coast and some areas just inland from here through Sussex and Kent we could see gusts 50-70mph, the strongest along Southeast coasts i expect, and 35-50mph gusts across inland SE England and possibly other parts of the S/SW.

Recent radar:

Recent radar shows heavy rain moving into the SW now

The NAE accumulated precipitation up to midnight tonight indicates 15-20mm quite widely and

as much as 20-45mm across parts of Central Southern and SE England:

GFS accumulated precipitation up to midnight shows 15-17mm widely:

The surface pressure at 0900am on NAE shows the small-scale in size but potent low:

There are two low pressures systems on the above chart of interest, the one we are focusing on at this stage is shown over Southeast England here at 9am or where NAE expects it to be placed at that time.

NAE ppn at 0300hrs-0900hrs this morning, some very heavy downpours can be expected through Sunday and with these a higher chance of the rain turning to wet snow over the hills, or sleet at

lower levels, but i must say that it's a low risk of anything at low level.

(keep watch on Dew points/Surface temps)

A move south of the low and we could see a higher sleet/snow risk and a move north i would expect the stronger winds on the South coast to be further inland.

We could also see hail, the GFS 500hpa shows very cold temperatures at that level, chart is for 1200hrs:

There is a risk of thunderstorms please see the convective thread for the information.

Last of all below is a warning map i have created to show where i expect the most severe weather to be from the data i have looked at, a few of those charts are posted above.

ESS

Edited November 4, 2012 by ElectricSnowStorm

[Snow and storms]

gusting really nice in the channel already. 40mph gust. You can really see the shape of the low, very tight and small using the http://www.xcweather.co.uk/ just a fraction to north west of bournemouth.

Just spotted the temp map on the same webpage, its really interesting checking out the differences in temp, Bournemouth is 10c and Dunkeswell just slightly to the west is 1c!!!

This cold air will be dragged down and round as the low pulls across us, so any sleet/wet snow will be on the west/north west side of the low I imagine.

Edited November 4, 2012 by Snow and storms

[Mumbles]

Couple of inches of snow has fallen here....bit of a shock to wake up to!