Jump to content
Sign in to follow this  
phil nw.

Model output discussion 14/04/18

Recommended Posts

1 hour ago, Ian Francis said:

In fairness 38.5 degrees' seem to give a pretty fair assessment of the GFS post the weekend. My interpretation was much the same - cold, wet and windy. Let's hope the ECM is right

It just isn't a fair assessment though, there is no way that run is cold, wet and windy all the way through. It's a poor run compared to virtually all the other models but temperatures for most would still reach the mid teens for many of us, with slight ridging on Wednesday and Thursday. By no means a washout at all in the reliable time frame. Yes Friday would be horrible but it's so far into FI that there's no point even contemplating the chart.

Share this post


Link to post
Share on other sites
13 minutes ago, Scorcher said:

It just isn't a fair assessment though, there is no way that run is cold, wet and windy all the way through. It's a poor run compared to virtually all the other models but temperatures for most would still reach the mid teens for many of us, with slight ridging on Wednesday and Thursday. By no means a washout at all in the reliable time frame. Yes Friday would be horrible but it's so far into FI that there's no point even contemplating the chart.

There's actually some snow at times in scotland on the Gfs 12z through low res and well below average temps generally, similar to the 6z.:cold:

Share this post


Link to post
Share on other sites

Pattern continues as expected with sceuro ridge building and lw trough ejection se towards Iberia. Question then becomes whether this trough becomes cut off and then is able to escape ne across nw Europe just to our se or cut off and meander around sw Europe. Alternatively it may not cut off and swing ne across w uk. Rinse and repeat. 

Share this post


Link to post
Share on other sites

Models still looking great out to Tuesday next week. Bank Holiday Monday in particular is looking very warm to perhaps even hot now:

114-582UK.GIF?03-0

GFS showing 25c, ECM looks a degree or so hotter to me. So all very dependent on the airflow/cloud amounts.

gfs-0-168.png ECM1-168.GIF?03-12
GFS then has a wobbly and really blows up the Atlantic low. ECM shows it too, but builds pressure back in rather than the low pressure domination shown on the 00z GFS op.

gefsens850london0.png

The GFS op is also on the lower pessimistic end of the ensemble range, so perhaps isn't indicative of the actual evolution. In a summary - very nice out to Tuesday/Wednesday, with a form of breakdown arriving from the west thereafter.

Share this post


Link to post
Share on other sites

UKMO looks quite humid as we go into next week with the chance of some thunderstorms around mid week

UW72-21.thumb.gif.9ffde78849f69d71a9fb308d10697e2e.gifUW96-21.thumb.gif.ab56ca7b21fac39ea953df08bec977d5.gifUW120-21.thumb.gif.2355afbf12070b5eeda776007f5868d1.gifUW144-21.thumb.gif.3e01cc62374395b3a02e131d0ef76fc5.gif

UW72-7.thumb.gif.ca6f8ea6a1b22218da6c54f5feb08741.gifUW96-7.thumb.gif.410d19d5981ee79e86ea32a5badd0dcb.gifUW120-7.thumb.gif.99bda2d0fc6abb5a9adc4475a06ebb7e.gifUW144-7.thumb.gif.6f29204e05408df2fa62c480ba69deb9.gif

Share this post


Link to post
Share on other sites

The latest models show an increasingly fine and warm BH weekend across most of the uk, certainly across england and wales with plenty of sunshine, light winds and temperatures into the low 20's celsius, warmest in the southeast. Early next week looks largely settled and warm too apart from the far nw / n but then there is strong support for the atlantic to break through with lows crossing the uk from around next midweek..but will it just be a blip with high pressure soon building in again or will it be the start of a more zonal atlantic driven spell?..for what it's worth i think the atlantic breakdown will / would be short-lived with a more blocked slow moving pattern returning.☺️

 

 

 

 

Edited by Frosty.

Share this post


Link to post
Share on other sites

Morning all :)

With a decent weekend heaving into view, how are we looking as the weekend after that approaches ? When I last looked a couple of days ago, there were plenty of hints the anticyclonic spell might break down to something more unsettled so let's move ahead to Sunday May 13th starting as always with the ECM 00Z at T+240:

ECM1-240.GIF?03-12

A decent evolution for many from ECM with the weekend's cell of HP easing east to be replaced by another midweek which in turn moves over Scandinavia. The T+240 char tis a little messy but with the jet held well to the north you'd think settled conditions would dominate especially for southern and central parts. A shallow area of LP to the west of Scotland doesn't look to be doing anything much at this time with the large Azores HP dominating to the west. Over Europe low heights have been pushed well to the south and south east.

GEM 00Z at the same time:

gem-0-240.png?00

A much more unsettled evolution from a model which has previously played the anticyclonic card very strongly. The weekend HP eases to the east by Wednesday but there is no second cell as per ECM. Instead, a much more active Atlantic brings LP and frontal systems toward the British Isles. The feature to the north of Scotland is in fact a secondary LP which swung NE across Ireland being gales and heavy rain to western parts. The forecast would be rain or showers for all with the heaviest rain in the north. Hint of a brief ridge coming through before further LP systems move in off the Atlantic.

GFS 00Z OP at the same time:

gfs-0-240.png

Again, more unsettled. As per GEM, an active LP sweeps in from the Atlantic passing to the NW of Scotland and by T+240 is easing away NE with a residual trough over northern parts while there are signs of pressure rising further south. Further into FI and an unusual evolution as LP develops over central Europe and moves WNW across the British Isles so a potentially cool and quite wet spell of weather around mid month.

GFS 00Z Control at the same time:

gens-0-1-240.png

The evolution in Control is similar to the OP if a shade more progressive. The deep LP moves away more quickly to the north and fills leaving a small trough over northern parts. Another curious evolution further into FI - pressure rises over Scandinavia and falls over Europe and a small but active LP moves west across southern Britain leaving all parts in a warm SE'ly.

The GEFS at T+240:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

The Mean suggests encroaching LP from the NW and there are only a couple of GFS members with anything like an ECM evolution so suggests that may be a shade of an outlier. Most have LP passing to the north of the British Isles but two or three hint at disruption SE across the British Isles and into Europe so possibly one to watch.

Further on and there's plenty of northern blocking but we've seen it before in high-res and it rarely comes through to low-res so at this stage I'd say the signal past mid-month is there is no strong signal at this time.

In summary, a fine spell through this weekend and into the middle of last week looks unlikely to continue much further. ECM tries to continue it but looks isolated as both GEM and GFS bring in more unsettled conditions off the Atlantic. GFS explores some synoptically unusual solutions further into FI but that's a long way off.

Share this post


Link to post
Share on other sites

Some of the 00z models showed an atlantic low crossing the uk next midweek introducing cooler more generally unsettled weather but the Gfs 6z has backed away from that idea and it stays warm next week across england / wales..indeed, very warm for the time of year with temps into the low to mid 20's celsius. It looks like a northwest / southeast split will be the outcome with  n / nw uk more exposed to the cooler changeable atlantic influence whereas the s / se continue predominantly settled and warmer. As I mentioned earlier my thoughts are that the further outlook would see a slow moving blocked pattern and I noticed those very words have also been used in the latest update from exeter.👍😀  👩‍👩‍👧‍👦

Edited by Frosty.

Share this post


Link to post
Share on other sites

High pressure eases away by midweek, but how much rain we'd see remains open to debate GFS keeps the vast majority of England and Wales dry at t144

GFSOPEU12_144_1.thumb.png.76a83f1930832acf36ea9e2c14e4fd70.pngUKMOPEU12_144_1.thumb.png.a20a3548eb80468f9c880ab4675085cc.png

New emoji's as well 👍

Edited by Summer Sun

Share this post


Link to post
Share on other sites

12s at T180, in order of increasing summeriness:

gem-0-180.png?12

gfs-0-180.png?12

icon-0-180.png?03-12

The ICON in particular looks promising, but I think we'll see high pressure spells interspersed with more unsettled spells for a while, that's been evident in the models for a while.

Share this post


Link to post
Share on other sites

That low looks menacing for mid-may! Tuesday the start of the breakdown, probably just holding on in the east. It’s still another good 5 day settled and warm spell for most. Can’t argue with that.

Share this post


Link to post
Share on other sites
36 minutes ago, Mike Poole said:

I think we'll see high pressure spells interspersed with more unsettled spells for a while, that's been evident in the models for a while.

I think you're right, that's what the Gfs 12z shows with short-lived atlantic incursions separated by high pressure building / ridging in with the warmer and more settled spells favouring the south of the uk and the most unsettled / cooler weather tending to be further n / nw.

In the meantime, the BH weekend looks a cracker across england and wales with warm weather persisting through most of next week across the s / e with very summery temps in the low to mid 20's celsius.☺️

Edited by Frosty.

Share this post


Link to post
Share on other sites

I'm interested in the longer range predictions for early summer, not looked at many runs yet, but the fact that  this sort of evolution is showing up on CFS at all is extremely promising, and may be one possible evolution into June of the current settled/ less settled oscillation shown in model output for May:

tempresult_vou5.gif

It's something I'm going to keep my eye on over the next couple of weeks, because if the jet stream does push north properly it could be a very good summer.

Edited by Mike Poole

Share this post


Link to post
Share on other sites
3 minutes ago, Mike Poole said:

I'm interested in the longer range predictions for early summer, not looked at many runs yet, but the fact that  this sort of evolution is showing up on CFS at all is extremely promising, and may be one possible evolution into June of the current settled/ less settled oscillation shown in model output for May:

tempresult_vou5.gif

Fingers crossed, a mix of warm / very warm anticyclonic and very warm / humid continental thundery spells would be my dream weather going forward into early summer and hopefully beyond!👍

Share this post


Link to post
Share on other sites

OK so this slap bang in the middle of the holiday weekend from ECM at T72, I know good weather has been nailed on for a while, but now the models are firming up the details, and with +12 uppers over the southeast this really could be an exceptional holiday weekend for many:

ECM0-72.GIF

ECM1-72.GIF?03-0

Edited by Mike Poole

Share this post


Link to post
Share on other sites

The Ecm 12z shows a big warm up as we import continental air into the uk during the BH weekend, especially sun / mon..mid 20's c for some..maybe higher in the most favoured spots,  especially the s / se..pretty much perfect bank holiday weekend weather across england and wales under high pressure with increasingly sunny, very warm weather with the warmth lasting well into next week further s / e and perhaps a thundery breakdown!🌩️⚡⛱️🌞

72_mslp850.png

72_thickuk.png

96_mslp850.png

96_thickuk.png

96_thick.png

Edited by Frosty.

Share this post


Link to post
Share on other sites

And to finish off the unsettled weather never seems to quite encroach, here at T240 on ECM, ridging from the Azores once again:

ECM1-240.GIF?03-0

JMA looking reasonably positive as well at T192, although this one does look like an orange duck that has swallowed something too big that has got stuck in its throat!!

J192-21.GIF?03-12

Edited by Mike Poole

Share this post


Link to post
Share on other sites
1 hour ago, Mike Poole said:

OK so this slap bang in the middle of the holiday weekend from ECM at T72, I know good weather has been nailed on for a while, but now the models are firming up the details, and with +12 uppers over the southeast this really could be an exceptional holiday weekend for many:

ECM0-72.GIF

ECM1-72.GIF?03-0

A strong jet stream looks likely from early next week from north America  ,yes a few fine days before it turns unsettled from the west on late Monday ...tuesday

hgt300-3.png

Share this post


Link to post
Share on other sites
2 hours ago, mb018538 said:

That low looks menacing for mid-may! Tuesday the start of the breakdown, probably just holding on in the east. It’s still another good 5 day settled and warm spell for most. Can’t argue with that.

Another good 5 days settled and warm spell... ?? It was absolutely horrid in North Wales today, barely reaching 13C and not a second of sunshine. Models showing another cloudfest for tomorrow. That is 3 days left until Tuesday.

20180503_185102.jpg

Edited by rain_shadow

Share this post


Link to post
Share on other sites
9 minutes ago, Mike Poole said:

And to finish off the unsettled weather never seems to quite encroach, here at T240 on ECM, ridging from the Azores once again:

ECM1-240.GIF?03-0

 

 

Yes mike after a bit of a blip the end of the Ecm 12z shows the azores ridging returning, at least further south and warming up due to a tropical maritime sw'ly airflow.☺️ 

240_mslp500.png

240_thickuk.png

240_mslp850uk.png

Edited by Frosty.

Share this post


Link to post
Share on other sites
13 minutes ago, Frosty. said:

Yes mike after a bit of a blip the end of the Ecm 12z shows the azores ridging returning, at least further south and warming up due to a tropical maritime sw'ly airflow.☺️ 

240_mslp500.png

240_thickuk.png

240_mslp850uk.png

Looks good to me, Karl. Wouldn't want to be in NW Scotland, though!🐐

Share this post


Link to post
Share on other sites
59 minutes ago, ANYWEATHER said:

A strong jet stream looks likely from early next week from north America  ,yes a few fine days before it turns unsettled from the west on late Monday ...tuesday

hgt300-3.png

The jet is shown as a diffluent flow, this can mean depressions deepening as they exit the left hand side of the flow into the trough. I wonder if this may be a feature we will see in that time scale?

Share this post


Link to post
Share on other sites
1 hour ago, rain_shadow said:

Another good 5 days settled and warm spell... ?? It was absolutely horrid in North Wales today, barely reaching 13C and not a second of sunshine. Models showing another cloudfest for tomorrow. That is 3 days left until Tuesday.

 

I was counting fri/sat/sun/mon/tue as the 5 decent days! I guess that was a tad imby.

Edited by mb018538

Share this post


Link to post
Share on other sites
3 hours ago, Frosty. said:

Fingers crossed, a mix of warm / very warm anticyclonic and very warm / humid continental thundery spells would be my dream weather going forward into early summer and hopefully beyond!👍

Not current model related, but synoptics and conditions in early-mid June are rarely a barometer for similar likely weather through rest of the summer, it usually takes until after the solstice before we see the northern hemisphere settle into its base summer state.. the position of the jetstream in late June is the best barometer, it can swing wildly through June as the atlantic awakens from its spring sleep.

Indeed now until mid June typically sees the atlantic in its quietest annual state, and it is very common to see the type of synoptics currently on offer, with diffluent weak meandering jet struggling against building ridge development. Its more unusual to see a very active jet with the atlantic barrelling in - but this becomes much more normal through second half of summer, its why I call the northern summer at least May-July (i.e. most settled sunniest period of the year, not necessarily warmest, or driest which goes more to April-June period ,but nearly as dry as then) - a warm summer doesn't make a good summer, if it is wet and dull as well, or even just average on the rainfall sunshine stakes.

 

Share this post


Link to post
Share on other sites
Just now, damianslaw said:

Not current model related, but synoptics and conditions in early-mid June are rarely a barometer for similar likely weather through rest of the summer, it usually takes until after the solstice before we see the northern hemisphere settle into its base summer state.. the position of the jetstream in late June is the best barometer, it can swing wildly through June as the atlantic awakens from its spring sleep.

Indeed now until mid June typically sees the atlantic in its quietest annual state, and it is very common to see the type of synoptics currently on offer, with diffluent weak meandering jet struggling against building ridge development. Its more unusual to see a very active jet with the atlantic barrelling in - but this becomes much more normal through second half of summer, its why I call the northern summer at least May-July (i.e. most settled sunniest period of the year, not necessarily warmest, or driest which goes more to April-June period ,but nearly as dry as then) - a warm summer doesn't make a good summer, if it is wet and dull as well, or even just average on the rainfall sunshine stakes.

 

 

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×
×
  • Create New...