Tracking the potential Polar Low - Thursday into Friday

[I Cumbria Marra I]

Agree that there is potential for 3-5 cm snowfalls along eastern flank of this rapid moving low.

 

Southwest Wales should be placed under a red alert for very strong winds overnight, pressure gradient on western flank of low looks extreme on meso-scale models. WNW to NNW 70 mph gusting to 110 is quite possible with this once it gets over the Irish Sea and moves inland in central Wales. For parts of Cornwall, Devon and western Somerset, 60 mph gusting to 100 by about 0300-0600h. These may be the greatest impacts of the system.

WOW!

[Barry12]

Could be Met Éireann?

 

Not sure if they have that warning, I can't read Irish.

 

Is that a joke?

 

Anyway, best place looks to be Northern Ireland at the moment.

[Nick L]

Agree that there is potential for 3-5 cm snowfalls along eastern flank of this rapid moving low.

 

Southwest Wales should be placed under a red alert for very strong winds overnight, pressure gradient on western flank of low looks extreme on meso-scale models. WNW to NNW 70 mph gusting to 110 is quite possible with this once it gets over the Irish Sea and moves inland in central Wales. For parts of Cornwall, Devon and western Somerset, 60 mph gusting to 100 by about 0300-0600h. These may be the greatest impacts of the system.

 

Really? Doesn't seem that bad to me. 

[Barry12]

Get set...a snow earthquake is quite possible if this Polar Low hits the British mainland.

[Gibby]

IMO I think many of posters here have an inaccurate track of this feature. I'm fairly certain it will track on current trajectory down through the spine of Wales, Bristol and the IOW. Snowfall East of that but how far uncertain and yes severe gales for a short time to the SW of it. Not quite sure which side of the coin I lie on. Time will tell.

[Dr. Astro]

Really? Doesn't seem that bad to me. 

 

Me either. Can see maybe 70-75mph gusts...

 

Roger - which mesoscale charts are you referring to.

[A.J]

Get set...a snow earthquake is quite possible if this Polar Low hits the British mainland.

Ah, I see the Daily Express hired you then Barry! 

[ANYWEATHER]

The NMM4 shows precip moving southeast with the polar low as expected breaking up over land. I don't think any computer model as got this one just right  ,with one or two places getting plastered with snow. Just shows you ,once you've got the cold in, let the fireworks start...

[snowydog]

Is that a joke?

 

Anyway, best place looks to be Northern Ireland at the moment.

 

Raining in Belfast City Centre at the moment

[weather eater]

IMO I think many of posters here have an inaccurate track of this feature. I'm fairly certain it will track on current trajectory down through the spine of Wales, Bristol and the IOW. Snowfall East of that but how far uncertain and yes severe gales for a short time to the SW of it. Not quite sure which side of the coin I lie on. Time will tell.

Looks a little further East to me gibby but I could be wrong, one thing for sure some people are going to end up disappointed, many maybe.

[i luv snow]

Raining in Belfast City Centre at the moment

 

I think only places to the east of this feature will see wintry ppn

[Nick L]

Raining in Belfast City Centre at the moment

 

Confirms that the western side of this feature is in the less cold air. Knife-edge stuff unfortunately.

[lorenzo]

Been waiting a while to see one of these live. Some images from Eumetsat and Satellite. The Lance satellite one is a biggie.

 

 

 

 

 

[TonyH]

Rain reports over NI so its official this is the first ever rainy polar low to hit the UK!

[i luv snow]

Rain reports over NI so its official this is the first ever rainy polar low to hit the UK!

 

On the western flank, but it seems to be remaining as snow on eastern flank according to net-wx radar!

[Dr. Astro]

Rain reports over NI so its official this is the first ever rainy polar low to hit the UK!

 

OK, we get it, you don't think it's a Polar Low besides the professionals calling it one.

 

P.S - Polar Lows can deliver rain, or snow. It's currently snowing on it's Eastern Flank in Scotland.

[mountain shadow]

I think only places to the east of this feature will see wintry ppn

BBC forecast just finished showed snow.

[Nick L]

On the western flank, but it seems to be remaining as snow on eastern flank according to net-wx radar!

 

This is based on model data, I'm guessing it will be solely 850 dry bulb temps. This is only one of many parameters that determine precipitation type.

Edited January 29, 2015 by Nick L

[KTtom]

Rain reports over NI so its official this is the first ever rainy polar low to hit the UK!

 

Bit of sour grapes for IMBY I think...no chance of anything else but rain on the western side of the lows in these set ups, short spell of heavy snow likely on the eastern side even further south.

Edited January 29, 2015 by KTtom

[mountain shadow]

Sleet at 410 feet South of Belfast

[simkin]

To the person who wanted the forming of the polar low saved

[edit] I'll upload the AVI (180MB), in a few minutes it will be at this link:

http://swmo.org/temp/polarlow.avi

 

Mini GIF preview:

 

 

It's currently snowing/sleeting in the New Forest btw - half a cm on the car.

Edited January 29, 2015 by simkin

[mountain shadow]

Bit of sour grapes for IMBY I think...no chance of anything else but rain on the western side of the lows in these set ups, short spell of heavy snow likely on the eastern side even further south.

No chance? Your obviously a more experienced forecaster than the met office who forecast a snow event for the East of NI. But heh ho, that's the weather for you.

[A.J]

ok, for comparison.......here's the current radar & NMM hi-res modelling (images courtesy NetWeather Extra)

 

radar grab 1 at 2000hrs showing ppn intensity & sferic detections

radar grab 2 at 2000hrs showing ppn type and weather station record dewpoints

NMM grab1 at 2000hrs showing ppn intensity

NMM grab 2 at 2000hrs showing ppn type

NMM grab 3 at 2000hrs showing modeled dewpoints

 

IMO, the NMM is overplaying the rain/sleet element of the 'chocolate teapot' low with lower dewpoints currently being measured over NI than modeled

 

    

 

    

 

 

[Jonathan Lang]

The NMM4 shows precip moving southeast with the polar low as expected breaking up over land. I don't think any computer model as got this one just right  ,with one or two places getting plastered with snow. Just shows you ,once you've got the cold in, let the fireworks start...

 

I hope this is right! I'm in the light brown bit on that chart!

Edited January 29, 2015 by Jonathan Lang

[Severe Siberian icy blast]

The NMM4 shows precip moving southeast with the polar low as expected breaking up over land. I don't think any computer model as got this one just right  ,with one or two places getting plastered with snow. Just shows you ,once you've got the cold in, let the fireworks start...

To be honest that already looks wrong though , it has the initial streamer far to far East , if you have a look at the current radar it's got that feature just much further west .

Also regarding ones who are fretting about it raining in Ireland remember Ireland's the most western part of our land , there will always be a warm sector on the Western side in these scenarios unless it's wrapped up in true polar air which I thought polar lows are lol shows what I no!