Short range model discussion - into 2018

[Polar Maritime]

6 minutes ago, knocker said:

That's interesting Polar, has it been officially identified as such?

On the BBC weather website during there video forecast they are calling it a Polar Low. Don't know if that's classed as official?

Edited February 26, 2018 by Polar Maritime

[Wardlegacy]

2 minutes ago, knocker said:

That's interesting Polar, has it been officially identified as such?

No a couple of forecasters on twitter called it this including John Hammond. He later explained that it wasn’t a true polar low but was an unusual feature.

[swebby]

9 minutes ago, knocker said:

As mentioned earlier the updated fax today for 1200 Friday should be interesting given the difference between last night's and the 0600 GFS

I'll echo what others have said -many thanks for your posts Knocker.

Can anyone confirm with the fax charts at what point, if any, do they switch from showing unmodified raw data to being modified by the forecasters?  My understanding was around T84 but i've only picked that up as hear say.

The T84 posted a bit further above for Thu @12z is showing the low being held further west of Biscay and elongating.  something Man with beard suggested as a possibility in the other thread.

[knocker]

4 minutes ago, Polar Maritime said:

On the BBC weather website during there video forecast they are calling it a Polar Low. Don't know if that's classed as official?

The reason I asked is because it's been signposted as a little wave for quite a while but not a particularly intense feature.It will be interesting to watch the satellite tomorrow.

[knocker]

The midday geostationary

[bluearmy]

43 minutes ago, Wardlegacy said:

No a couple of forecasters on twitter called it this including John Hammond. He later explained that it wasn’t a true polar low but was an unusual feature.

More ‘dumbing down’ !

[swebby]

1 hour ago, knocker said:

The reason I asked is because it's been signposted as a little wave for quite a while but not a particularly intense feature.It will be interesting to watch the satellite tomorrow.

I've been looking at the Fax charts and there is another reason to keep an eye on this feature. How this small system develops and exits the Uk is possibly quite important to long term prospects in that it looks to me like it may have a bearing on how Thu/Fri's low develops?

T48/60/72 shows it heading out well into the atlantic as a decaying occluded front then eventually a trough, where at T84 it  reinvigorates, developing a centre and becomes a small low that i think may have a bearing on the main low for thu/fri being held out further west? 

 

Edited February 26, 2018 by swebby

[Yarmy]

You can see the closed circulation on the putative polar low better on the high-res models. Arpege here.

 

I don't know what the technical definition is, but I vaguely remember something about it having to form poleward of the PFJ.

[knocker]

2 minutes ago, Yarmy said:

You can see the closed circulation on the putative polar low better on the high-res models. Arpege here.

 

 

I don't know what the technical definition is, but I vaguely remember something about it having to form poleward of the PFJ.

http://rammb.cira.colostate.edu/wmovl/vrl/tutorials/satmanu-eumetsat/SatManu/CMs/PL/backgr.htm

[knocker]

If anyone is interested in keeping an easy eye on current temps

https://wow.metoffice.gov.uk/

 

[Nick L]

Some differences between the hi-res models for tonight's snow across the Midlands and northern England. UKV gives Manchester a good dollop of snow, while Euro4 has the main thrust going through Staffordshire and Shropshire.

[Rocheydub]

18 minutes ago, Nick L said:

Some differences between the hi-res models for tonight's snow across the Midlands and northern England. UKV gives Manchester a good dollop of snow, while Euro4 has the main thrust going through Staffordshire and Shropshire.

Just noticed the divergence across great swathes of the land mass. Really is a case of nowcasting Nick.

[knocker]

20 minutes ago, Nick L said:

Some differences between the hi-res models for tonight's snow across the Midlands and northern England. UKV gives Manchester a good dollop of snow, while Euro4 has the main thrust going through Staffordshire and Shropshire.

The GFS-WRF covers all angles

[knocker]

The 1400 high res. MODIS is westerly but it does show the mass of showers reaching a long way west

[chrisbell-nottheweatherman]

42 minutes ago, knocker said:

The GFS-WRF covers all angles

Would we expect the Lincolnshire Wolds, North York Moors and Pennines to be the initial areas for snowfall?  Presumably the Peak District and the hills of the NW Midlands will see snow later in the night?  Seems as though my area might well be dry.

[DEYS(Kent)]

Little feature being progged on ICON for the past 12 hours Tues into Weds..Could be a surprise for us Kent folk..

[chrisbell-nottheweatherman]

1 hour ago, knocker said:

If anyone is interested in keeping an easy eye on current temps

https://wow.metoffice.gov.uk/

 

Are these data likely to be more accurate than those on Wunderground?  I use the UEA weather station on Wunderground as it's far enough from the centre of Norwich to be relatiely unaffected by the Urban Heat Island effect, plus, knowing UEA as a former graduate, it lies partly in a hollow in a river valley while my village, a few miles south, sits on an area of higher ground.  I'd therefore expect to be cooler by day through altitude and warmer at night during winter as the cold air drops into the Yare valley.

Edited February 26, 2018 by chrisbell-nottheweatherman

[Staffordshire]

1 hour ago, Nick L said:

Some differences between the hi-res models for tonight's snow across the Midlands and northern England. UKV gives Manchester a good dollop of snow, while Euro4 has the main thrust going through Staffordshire and Shropshire.

When can we realistically expect a solid answer, after the 12z's or is it more of a radar watch?

[knocker]

2 minutes ago, chrisbell-nottheweatherman said:

Are these data likely to be more accurate than those on Wunderground?  I use the UEA weather station on Wunderground as it's far enough from the centre of Norwich to be relatiely unaffected by the Urban Heat Island effect, plus, knowing UEA as a former graduate, it lies partly in a hollow in a river valley while my village, a few miles south, sits on an area of higher ground, therefore I'd expect to be cooler by day through altitude and warmer at night during winter as the cold air drops into the Yare valley.

As for accuracy i've no idea but as they are official sites I doubt you will get better. If you change the filters you get a much bigger coverage,

[chrisbell-nottheweatherman]

1 minute ago, knocker said:

As for accuracy i've no idea but as they are official sites I doubt you will get better. If you change the filters you get a much bigger coverage,

I'm using all the sites anyway - our nearest Met Office station now is at Marham which is nearly 30 miles away (bring back Norwich weather station!)

[knocker]

10 minutes ago, chrisbell-nottheweatherman said:

Would we expect the Lincolnshire Wolds, North York Moors and Pennines to be the initial areas for snowfall?  Presumably the Peak District and the hills of the NW Midlands will see snow later in the night?  Seems as though my area might well be dry.

Can't see your area getting a huge amount from the 00 WRF but who knows at this stage?

 

[knocker]

Just now, chrisbell-nottheweatherman said:

I'm using all the sites anyway - our nearest Met Office station now is at Marham which is nearly 30 miles away (bring back Norwich weather station!)

And Plymouth

[knocker]

The one problem with the geostationary is it doesn't give you the fine detail but an interesting view of our low at 1500 all the same. (Dundee Satellite Receiving Station)

[johnholmes]

36 minutes ago, knocker said:

And Plymouth

and many more, sadly not a cat in thingies chance!

[johnholmes]

Current 12z Fax for Wed shows most of the UK within the 510 DM line. Not often seen even in mid winter let alone 2 days before official spring. No worries about what falls from the skies with that upper air.