Model output discussion 14/04/18

[northwestsnow]

18Z was actually one of the cooler runs mid term!

[Djdazzle]

Great ECM esrlier but way too soon to say it’s a trendsetter. Tamara has suggested that the Azores high may ridge in towards the final part of the month, so maybe the ECM was toying with that scenario.

[mb018538]

Runs this morning not nearly as good as last nights ecm....but not bad either. Doesn’t look like too much ppn again down south, accumulated ppn charts only showing 3mm in the next 10 days....been so very dry here for a long time now.

[bluearmy]

the semi permanent sceuro ridge now lost and more mobile pattern established. As others have mused - is this going to become the form horse for the next four/six weeks or will we see a reversion to the sceuro ridge/Atlantic trough ? the models seem unsure in the 6/10 day period which way is best to go - the eps only with one extended cluster on the 12z run is unhelpful for the 10/14 day term and perhaps that entire suite (with the v warm op run not particularly well supported) is less reliable than might be hoped. 

the theme of summer remains generally excellent (this less settled period we are currently in is hardly dire countrywide) but what July might have in store ..............

[Man With Beard]

31 minutes ago, mb018538 said:

Runs this morning not nearly as good as last nights ecm....but not bad either. Doesn’t look like too much ppn again down south, accumulated ppn charts only showing 3mm in the next 10 days....been so very dry here for a long time now.

So topsy turvy at the moment even at short range! Huge variations run to run on how far north the jet will be. Two things though 1. spot on about the rain, could some parts of the south be headed for a near zero rainfall total for the month? and 2. the jet seems to be dying off again by next weekend, a trend on all models for a few runs now. 

[Frosty.]

28 minutes ago, Man With Beard said:

 the jet seems to be dying off again by next weekend, a trend on all models for a few runs now. 

That's good news in itself I would say!

[mushymanrob]

15 hours ago, CreweCold said:

One thing that has been a clear trend recently is that troughing is shown to push further and further S. It's a gradual deterioration with the NW of the UK seeing the most unsettled of the conditions first of all.

In the mid range we see the unsettled weather push across most of the country 

Not dire by any means but a far cry from the glorious May we experienced.

On another note, the CFS (which was so bullish about an extensive mid lat high across the UK) is backing away from the glorious July it once promised

The UKMO now shows at day 6 the beginning of the break up of the +NAO signature which has promoted the fine weather we have enjoyed, you can see the deeper Greenland troughing begin to dissipate

youre forgetting a lot of eastern areas didnt get a 'glorious' may, a lot of us away from the west was plagued by cloud.

[mushymanrob]

noaa anomaly charts dont support any pattern change either way, retaining the brisk upper westerly which will prevent anything other then transitory ridging. but with positive heights across most of southern uk theres no great problem with rain, in fact the rather dry theme looks set to continue for some time away from the northwest.  a lot of pleasant summery weather then, with the warmest/sunniest in the south/southeast.

 

[mb018538]

Looks fine to me, westerly based ridging is better than a trough. Being in the south and east I’ll obviously benefit most, so from an imby point of view I’ll take it!

[Guest]

While not as hot as some of last nights runs the overall synoptic scenario is much better than 24hrs ago, certainly appears to be a notable reduction in the chance of troughing or low pressure in general starting to take over next weekend. I would not be surprised to that southerly flow develop over the U.K. (I mentioned this yesterday) in the 6-10day time frame. Watch out for something notably warm into the last week of June.

[Singularity]

Yes... a trend noticed in the det runs toward the subtropical ridge retraction being sharper, to the extent that a trough is able to dig down west of the UK instead of across it, with the potential for a ridge over or east of us.

Such sharper ridge-trough combinations are one of the possible results from reduced Arctic sea ice. Not saying this is necessarily behind the current trend, but it could be at least part of the equation...

[johnholmes]

Looking at the latest 6-10 day 500 mb anomaly output suggests that any upper ridging is a short lived affair with a mainly westerly pattern showing. You can see this, albeit certainly not cast in stone, on this morning's ECMWF if you play the previous chart from yesterday. This has a marked +ve ehight anomaly this morning no sign. NOAA also shows this over the past 2 days or so. I generally take NOAA as the most reliable with EC following and GFS some way behind unless it is similar to the other two. No GFS either yesterday or today on the link I have. The 8-14 NOAA similar to the 6-10. To me it remains looking like a NW-SE split on average through the next 2 weeks. Obviously they are 'mean' charts and some divergence on occasasional days will occur but no major difference over the period as a whole.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

[Weather-history]

 

The GFS 06z op run was a dry run for most of England and Wales

[I remember Atlantic 252]

6Z though, the cold front is back, looks not great for many on Thurs, all about the timing of the front, Wed could be decent away from far north

[northwestsnow]

41 minutes ago, Weather-history said:

 

The GFS 06z op run was a dry run for most of England and Wales

Yes Kevin, dry is the key word on this mornings output although we can see dry is not the buzzword for those across NW Britain,infact it looks thoroughly awful for NW Scotland in particular.

[Frosty.]

A very good Gfs 6z operational for southern uk with predominantly settled warm conditions  bar the odd cooler day in high res..next thursday for example but the warmth  soon returns and stays until deep into low res..really it's all about high pressure / ridging  building in and rebuilding in throughout with most of the unsettled weather mainly brushing across northern uk where it also looks cooler but even the north has some decent fine spells too.

Edited June 16, 2018 by Frosty.

[Guest]

Lol the perils of model watching, last gfs had 30c forecast for the south on Thursday and 25+c for 6/7days, today Thursdays forecast is just about scrapping 20c in London. Pretty good agreement that high pressure will now regress westwards allowing a rapid decline in temps in the second half of the week. 

Talking of decline in temps only 15c here today so a poor summers day.

[I remember Atlantic 252]

1 minute ago, Alderc said:

Lol the perils of model watching, last gfs had 30c forecast for the south on Thursday and 25+c for 6/7days, today Thursdays forecast is just about scrapping 20c in London. Pretty good agreement that high pressure will now regress westwards allowing a rapid decline in temps in the second half of the week. 

Talking of decline in temps only 15c here today so a poor summers day.

all depends how far south Wednesdays cold front gets, yesterday never reached here with 9 degrees max in NW Scotland, on todays 6Z reaches the south coast, cold air behind that front

[Frosty.]

The GEFS 6z mean is dominated by azores ridging until well into low res so predominantly fine and warm sums it up, best across most of england and wales, especially further south..cooler for northern uk.

Edited June 16, 2018 by Frosty.

[northwestsnow]

BINGO!!

UKMO is beautiful this evening and backs up the beautiful meto update from earler today, HPp firmly in charge pretty much from start to finish a while therafter by the looks of the 144 chart!!

[Sweatyman]

8 minutes ago, northwestsnow said:

BINGO!!

UKMO is beautiful this evening and backs up the beautiful meto update from earler today, HPp firmly in charge pretty much from start to finish a while therafter by the looks of the 144 chart!!

Sounds great. Haven't seen the update yet.

[mb018538]

Looks nice enough, very cold 850s though for late June - 0 to 2c across a lot of the country, so don’t expect any great shakes temperature wise. High teens at best I’d have thought?

[northwestsnow]

A really nice GFS to add to UKMO!!

Again, no heatwave and no huge uppers but late June wherever the sun breaks through temps will respond..

edit the deeper the runs goes the warmer it gets ..:D

Edited June 16, 2018 by northwestsnow

[Frosty.]

Nice Ukmo 12z.. great to see high pressure in the ascendancy!

Beyond T+144 would be even better as the 1030 mb high drifts east right over the uk.

Edited June 16, 2018 by Frosty.

[I remember Atlantic 252]

18 minutes ago, mb018538 said:

Looks nice enough, very cold 850s though for late June - 0 to 2c across a lot of the country, so don’t expect any great shakes temperature wise. High teens at best I’d have thought?

Yes, chill in the air I feel and a lot of cloud perhaps drizzle away from the S/SE