SnowStorm(Jamie)

Cheers for that, yes the link works and it gives a better view of the Dewpoints - Inland parts of NW/N Wales could well see some snow showers if those dewpoints remain low enough. Further South and West its looks more marginal

After checking the GFS 12Z it looks as if the cold thrust from the NW comes slightly later than the 06z run and there are differences on how they handle that frontal wave running SE on the 12Z its further North and we see allot of heavy rain moving in to Wales especially in the South while on the 06z run of the GFS it was further South. Note the diffrences on the 12Z and 06Z precipitation charts for the same time: http://hw.nwstatic.c...2/81/ukprec.png <12z http://hw.nwstatic.c...6/87/ukprec.png <06Z Again we see the colder -5C upper air come over Wales allong with the SUB 528DAM line: http://hw.nwstatic.c.../h850t850eu.png http://hw.nwstatic.c...hgt500-1000.png Also adding in the dew points for later on Monday & as we head into Tuesday: http://expertcharts....120518_0112.gif http://expertcharts....120600_0112.gif Generally around 0C in N. Wales and Mid Wales, above freezing around coastal areas - So if any sleet and snow showers are to be expected it will largelly be confined to N Wales and any showers that push in to Mid Wales, however the western side of the Cambrian Mountains will be most prone to showers in this airflow.

The colder upper air temperatures of -5C and the sub 528DAM line just about cover Wales on the GFS 06z run: http://hw.nwstatic.c.../h850t850eu.png http://hw.nwstatic.c...hgt500-1000.png However not for long as some slightly milder air begins to filter in from the west for Tuesday. There is still uncertainty regarding the frontal wave or low that is running SE on Sunday - So changes can be expected as the models pin down details on this features intensity.

Its looking increasingly likely that we will see a thrust of cold Polar Maritime air from the NW with upper air 850hpa temperatures of -5C flooding SE over Wales. However how potent this cold shot will be is undecided yet, and ive noticed today that the sub 528DAM line is shown slightly further northwards on the GFS model at least when considering the period of Monday going into Tuesday next week. - That being said that line does still lie across Mid & North Wales: http://hw.nwstatic.c...hgt500-1000.png To add keep in mind the sea surface temperatures over the Irish sea, currently these are above average with temperatures of just over 12C this is important because the strong NW surface flow will be comming right over the Irish Sea and this will keep temperatures higher especially for areas closer to the coastline. As it stands higher parts of N/NW Wales will be the most likely location for snow showers. Met Office Outlook for the Brecon Beacons on Monday is shown here: http://www.metoffice...t_pressure.html The sleet/snow showers around the peaks theme fits in with the 0C Isotherm chart from the GFS on Monday which shows the freezing level around 700-800M: Still worth keeping an eye on though since its still 5 days out yet. I wonder if the GFS 18z will again show that frontal wave running SE on Sunday developing more rapidly and becoming more intense it has done this since Sunday, if that happens we will more likely see the cold air flooding southwards more rapdily on the rear of it i think.

I think the flow from the NW is likely models have been showing this for sometime now, how cold that flow will be though remains uncertain at this point. We need that thrust of cold air more directly from the North, the models do show this albeit briefly (around the 120-144hrs mark). But the most likely location for snow is still around the higher ground of N. Wales perhaps extending southwards if we pick up that colder flow. So we need to keep an eye on how the models show this pattern developing over the next few days.

Pretty impressive winds gusts across Wales today, Met Office observations show that Capel Curig had a wind gust of 81mph @1300hrs. Whats also noticeable is the sharp drop in temperature once the cold front has passed. My own station has shown a drop of -4.7C per hour, which is simular to the one at Capel Curig which went from 11.2C to 6.8C in an hour so a drop of exactly 4.4C in the hour.

There looks to be some strong winds and heavy rain across Wales tomorrow as we see the trough currently in the Atlantic progress eastwards towards the UK. The models have been showing that the trough will gradually dig down over the UK and parts of Europe as we go later into the week and we pick up a colder flow from the North West. As for snow here in Wales it seems rather unlikely at this point away from the highest elevations in N. Wales, unless we see a flow that is more directly from the North allowing colder arctic air to flood southwards - This has been hinted at on the models but its a fair way out yet onwards from 144hrs. As for Tomorrow the Metoffice Fax chart above shows a cold front pushing east with strong winds especially in W/SW parts of Wales as shown on the NAE model: http://expertcharts....112909_2812.gif So feeling cooler once that cold front pushes through with some showers about in Western parts of Wales associated with that trough shown behind the cold front on the Met O fax chart.

Some strong winds can be expected for North Wales late Saturday and as we head into Sunday as a deepening area of Low pressure runs up towards the NW of the UK: http://hw.nwstatic.c...2/39/ukwind.png A cold front will push SE during this time so by Sunday feeling cooler as colder air filters down behind the area of low pressure as shown on the Met O fax chart for Sunday: http://www.meteociel.../fax/fax48s.gif I agree, snow seems unlikely for a while yet with the most likely case being shots of Polar Maritime Air from a NW flow on the rear of low pressure systems, and such a flow at this point is unlikely to be cold enough to bring any snow this far South apart from the peaks around Snowdonia. Unless of course we see high pressure ridge up towards Greenland temporarily allowing for a more Northerly flow as shown on tonight's 12z ECM - but that's a long way out yet.

Certainly a cooler feel out there today as some cooler surface air filtered around that area of high pressure to our East, delivered to us on a South Easterly flow off the continent. Just been looking at the Met Office observations and i noticed that Lake Vyrnwy only got to 4C at 2pm: http://www.metoffice...st_weather.html The lake is surrounded by hills of up to 400m though.

Indeed certainly impressive high temperatures for the time of year. Looking at the Met Office latest observations it shows Valley @ 17.9c! Taking a look at the Met Office Fax chart for today below we can see why we are getting this warm weather: You can see the Atlantic trough to our west with that blocking high towards our east drawing up South Easterly winds. As we head further in to next week the models show that trough towards our west pushing gradually eastwards towards the UK which would result in more unsettled weather with rain for Wales.

Got down to -0.5C at 7am this morning here in Swansea with a slight frost. Was nice to see the first frost of the autumn here.

Below is the 36hr precipitation accumulation being projected by the NAE model: http://expertcharts....110106_3018.gif You can see the higher accumulation levels towards West and SW Wales where around 25mm is expected, GFS model also showing very much the same amounts for the same time frame: http://expertcharts....110106_3018.gif More rain is to be expected as the trough and associated low pressure move eastward towards the UK with weather fronts moving in from the South/SW as shown on the Met O Fax chart for Wednesday: http://www.meteociel.../fax/fax72s.gif

Thanks for posting link to cams, nice early start to winter for those in the NE US. Some spots expecting around 12 inches of snow, which is very impressive. Also some pics here: http://www.accuweath...snowstorm-i.asp

Certainly allot of rain in SW Wales today, for hours the front barely moved with heavy precipitation running up along the front running into the same areas SW England, SW Wales, Ireland & N Ireland. Finally the cold front has started to head NE with a squall line forming on it's back edge which give some heavy rain here in Swansea and some fairly strong winds- Gust of 55mph recorded at Mumbles.

Just checked both the NMM and the NAE models and a slight eastward shift in the front is present. Here's the 24hr precipitation accumulation from the 0z NAE model: http://expertcharts....102500_2400.gif Serious amount of precipitation accumulation being shown along the SW coats of Pembrokeshire, Met Office amber alert has also been issued for that region: http://www.metoffice...t_warnings.html

Yup Met Office site at Mumbles head @ 2300hrs recorded a gust of 46mph. More of the strong winds tomorrow i would say with the low running up towards our SW: http://expertcharts.weatheronline.co.uk/daten/proficharts/en/nae/2011/10/23/basis18/ukuk/pslv/11102415_2318.gif Just a few spots of rain here the heavier stuff formed to the NE.

I agree, latest NAE shows the front just about grazing the far SW of Wales, again with the heaviest precipitation out to sea: http://expertcharts....102409_2318.gif Very intense narrow band of precipitation being shown for just off sea looking to run through Cornwall though but again if there's an eastward shift perhaps the far SW of Wales to: http://expertcharts....102412_2318.gif Met Office seem to go along with the NAE model with an Amber alert issued for Cornwall and extending not to far from coastal SW Pembrokshire: http://www.metoffice...ings.html?day=2 The GFS 18z shows the precipitation in the same place as previous runs today, although it does indicate the risk of some of the intense precipitation running into Pembrokshire: http://hw.nwstatic.c...8/21/ukprec.png

Definitely there's a westward shift visible in this front compared to yesterdays 12z GFS which took the heaviest of the precipitation up through SW England/East Wales/West Midlands and then up into NW England. The 12z coming out now shows the front hitting Wales with the heaviest precipitation towards SW Wales: http://hw.nwstatic.c...2/27/ukprec.png The NAE shows much the same with the front being most intense towards the SW Of Wales: http://expertcharts....102409_2312.gif Something to watch because it wouldn't take much of a shift eastwards of the low pressure to bring that very heavy area of precipitation out in Irish Sea into parts of SW Wales e.g. Pembrokeshire. Also some strong gusty winds can be expected along the South Coast of Wales tomorrow as shown by the NAE: http://expertcharts....102415_2312.gif This also transfers to NW Wales later in the day: http://expertcharts....102418_2312.gif

Yes south Wales should miss the worst of the rain, though looking at the latest NAE and GFS some heavier pulses of rain are likely in SE Wales.

Had some heavy showers around here gone 2pm no thunder or lightning, looking at the radar it did intesify towards west Swansea.

Yup it just went right over me...thunder and some lightning. The rainfall intensity was most impressive though

Good to see people having snow- Had snow here today when i was out at about 250m was heavy and sticking to the top of the mountain. Snow should turn back to rain for the low ground of Southern Wales later as some milder air starts to move up from the South. Also snow to come in N/NE Wales where the colder air is still in place as the front runs into it: http://expert.weathe...022318_2306.gif < Upper air http://expert.weathe...022318_2306.gif < Dewpoints

Just to point out some of the Met Office advisories have recently been updated by the looks of things: http://www.metoffice.gov.uk/weather/uk/wl/wl_forecast_warnings.html

Yup i wouldnt rule out snow to lower levels of SE Wales (inland parts) as the front hits in to the colder air- Although the snow risk will transfer more to higher ground i think as the day goes on due to some milder air starting to move in.

Np Andy- With you being further east and with elevation you are likely to see some snow tomorrow probably changing back to rain later in the day though.