Model Output Discussion 12z 03/04/13

[Captain Shortwave]

UKMO is moving into line with GFS now at t144! not often GFS leads the way quite a back track from UKMO compared to this morning

UKMO 00z left UKMO 12z right

Much better this afternoon the chance of the first Spanish plume of 2013 the first 20c of 2013 is more than possible in the south going by the 12z for next Sunday

Yesterday you said that the high on the ECM was perfectly placed. I think you are wrong.

This is perfectly placed, a southerly sourced straight from the Sahara desert anyone. There will be panic buying for bbq equipment off this

[I remember Atlantic 252]

Yesterday you said that the high on the ECM was perfectly placed. I think you are wrong.

This is perfectly placed, a southerly sourced straight from the Sahara desert anyone. There will be panic buying for bbq equipment off this

And at 384 a screaming northerly straight from the arctic!

[Captain Shortwave]

GFS ensemble mean at day 7

Not bad eh

[Frosty.]

EPIC Northerly on Gfs 12z, shame it's so far out but just shows the colder than average arctic would still produce a potent Arctic blast in late April, it's the type of northerly I have been craving all winter and we never got 1 single potent northerly through the winter and spring so far. A warm up later in the week and next weekend is now likely with a thaw for the snowy scottish hills and mountains by next weekend.

[Summer Sun]

Next Sunday could be quite warm going by the ensembles

[Summer Sun]

So out of the main 3 at t144 tonight its ECM which is the odd one out it sticks with its low pressure set up

Whilst UKMO and GFS bring us a taste of summer with temperatures pushing 20c in the south by Sunday (14th) next week with southerly winds coming our way

NAVGEM is the most extreme tonight with a 950mb low crossing to the north west of Scotland next Sunday

[Frosty.]

So out of the main 3 at t144 tonight its ECM which is the odd one out it sticks with its low pressure set up

Whilst UKMO and GFS bring us a taste of summer with temperatures pushing 20c in the south by Sunday (14th) next week with southerly winds coming our way

NAVGEM is the most extreme tonight with a 950mb low crossing to the north west of Scotland next Sunday

pin the tail on the donkey, none of the models seem to know which track the low will take and it's depth, we should have a better idea tomorrow.

[Milhouse]

All 3 main models do show a big vigerous low pressure approaching the UK scooping up a lot of moist tropical air. Its path is still uncertain though. ECM has it surging northwards up the NW coast of Scotland and dragging up the Azores high northwards on the back of it. UKMO at the other end of the scale has an area of high pressure developing in front of it bringing potentially a settled and increasingly mild weekend.

[Milhouse]

This would be great for getting rid of that stagnant cold air.

[Zenarcher]

Here's a comparison between the GFS, ECM, UKMO, GEM, JMA and NAVGEM at 144 hours and how they handle this low,

The GFS, GEM and UKMO have it sink south as more pressure builds up over the UK, meanwhile the ECM JMA and NAVGEM have the low deeper and it goes straight across into the UK.

[Bradowl]

Does look as though the Med is going to warm up very nicely over coming couple of weeks.

Just in time for some of us.

[Guest pjl20101]

Have got the latest CPC 8-14 day output with the +ve output still in charge of SE Britain:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

Looking very promising indeed and possibly a taste of summer on the way. Tonight I disagree with the ECM for once and think that GFS will be closer to the mark.

Edited April 7, 2013 by pjl20101

[tinybill]

http://www.meteociel...?mode=2&ech=204

reading some on here i.e.spanish plume dont look deep fantasy world winter not done yet!!!

Edited April 7, 2013 by tinybill

[Gibby]

Good evening. Here is the report of the 12z output from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday April 7th 2013.

All models show another rather chilly week to come though less so than recently. With each passing run the models seem more determined to keep the UK under rather colder conditions with less of an attack from the milder air to the SW which remains steered largely into France and Spain with the attendant depressions staying close to or moving across Southern England before a change to a slack north or NW flow develops at the end of the week with brighter spells, a few showers and night frosts to close the working week out.

GFS then has the UK under a mild Southerly flow as High pressure migrates North to the East of the UK. For us troughs of Low pressure quickly infiltrate the UK with rain at times edging East early in the following week clearing to lighter West winds and scattered showers. The remainder of FI has High pressure over the UK for a time with fine and bright weather with average temperatures before a strong Greenland High develops and pulls a strong Northerly flow with wintry showers and frosts at night to end the run.

The GFS Ensembles show less cold conditions this week though still rather cold before a general trend to somewhat above average temperatures seems possible with rain at times in the coming week lessening so in the final week with the usual wide scatter between the members later. The operational's cold plunge at the end is not supported.

The Jet Stream shows the flow continuing South of the UK for the time being with the programmed shift North held off until next weekend and onward as it turns NE over the UK and more Northern areas of Europe the week after next.

UKMO shows High pressure over the UK next weekend with a frosty start followed by a bright dry day with the prospect of another frost on Saturday night.

GEM tonight has a ridge of high pressure to the East of the UK on Saturday with a strengthening Southerly flow bringing rain in from the West within 24 hours of term of the run.

NAVGEM shows a ridge too over the East of the UK with a strong Southerly then SW flow developing across the UK as a deep low heads slowly NE between Scotland and Iceland with rain and strong winds looking likely for many for some days.

ECM tonight shows the Southerly flow veer west with rain at times late in the weekend before the weather slowly settles down as High pressure builds from the South with some above average temperatures possible by midweek in Week 2 over the South.

In Summary the weather looks like staying rather chilly and unsettled this week before things show signs of improving from some output next weekend as a ridge moves up from the South along with the Jet Stream potentially steering further depressions NE at much higher latitudes with milder if rather changeable conditions developing for many away from the far NW.

[Summer Sun]

http://www.meteociel...?mode=2&ech=204

reading some on here i.e.spanish plume dont look deep fantasy world winter not done yet!!!

Its a cold outlier outlier in FI as I've shown here -

[Guest pjl20101]

Am singing from the same hymn sheet as Gavin as its not supported by the other models. We will have to wait for the 18Z to get some info that may be nearer the mark.

[phil nw.]

Have got the latest CPC 8-14 day output with the +ve output still in charge of SE Britain:

http://www.cpc.ncep....14day/500mb.php

Looking very promising indeed and possibly a taste of summer on the way. Tonight I disagree with the ECM for once and think that GFS will be closer to the mark.

Yes that upper pattern for the anomalies has been showing consistently for a few days now.

Looks likely the far north west could remain more unsettled based on recent mean outputs but a lot depends how much the jet ridges to the east of the Atlantic trough.Some Op runs have placed the surface high nearer to the UK.which would see much of the UK settled and reasonably warm.

A decent prospect for something warmer and brighter though in that south to south westerly flow, certainly for the more southern and eastern UK beyond this week.

[Summer Sun]

The ECM ensemble once again goes for west to south westerly winds tonight

[SP1986]

Beautiful.. it's called the average British air flow, and has become increasingly rare in recent times..

[damianslaw]

Next four-five days will see a continuation of the below average temperatures for many and becoming generally unsettled with the first dose of proper rain for many come Thursday though the NW looks like staying dry, before we see a ridge development behind the low pressure ushering in what could be our first spell of proper spring warmth.

So a little patience is required for those wanting a change to springlike warmth, but if the GFS and UKMO verify then next weekend could be a very mild affair for many especially the south and southeast. The number of dry weekends this year has been well above the norm, indeed I don't believe here in the NW we have had one washout weekend yet... mmm watch them arrive in succession just in time for the start of the summer season!

[Cheshire Freeze]

Sorry I can't resist it. 510 dam about to reach N Scotland 1 week before May begins......Oh behave yourself GFS!

[Guest pjl20101]

Sorry I can't resist it. 510 dam about to reach N Scotland 1 week before May begins......Oh behave yourself GFS!

I wouldn't trust GFS if I could throw it CreweCold as it isn't supported by NOAA, best idea is to keep tabs of the CPC my friend like I mentioned earlier tonight.

[Cheshire Freeze]

I wouldn't trust GFS if I could throw it CreweCold as it isn't supported by NOAA, best idea is to keep tabs of the CPC my friend like I mentioned earlier tonight.

That's just it I wouldn't put any faith in anything at 384 hrs out. Just couldn't resist posting the chart!

[Cheshire Freeze]

Nasty conditions if this comes off

I noticed a similar feature on the ECM for the same timeframe when I checked earlier

Will check the ensembles in a bit to see if this has any support. Certainly looks to be the chance of a fairly noteable wind storm. Oh and probably a nice convective cold front thrown in there too.

Edited April 7, 2013 by CreweCold

[Panayiotis]

Nasty conditions if this comes off

I noticed a similar feature on the ECM for the same timeframe when I checked earlier

Will check the ensembles in a bit to see if this has any support. Certainly looks to be the chance of a fairly noteable wind storm. Oh and probably a nice convective cold front thrown in there too.

Yes it does look like the GFS has made a step towards the ECM on the 18z. Edited April 7, 2013 by Panayiotis