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Model Output Discussion 31/03/14 onwards.


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Thank you knocker and johnholmes for your time and replies :) 

They have indeed helped. Always a learning curve the weather isnt it. Very fun though!

 

As mentioned already it isn't easy looking at simple synoptic charts of parameters such as pressure or temperature to try and identify fronts. However, if you have access to charts with station circles and begin to plot a few simple variables, such as isobars, isodrosotherms (areas of equal dewpoint - very useful as different air masses will have different humidities, and a front divides airmasses!) and try and spot wind veer...combine that with simple knowledge of clouds and types of weather you'd expect along different fronts and you'd actually not do too badly identifying where they are!

 

However, it's much easier to look at the charts with these frontal features already positioned for you :wink:

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As mentioned above, it seems like a considerable shift in synoptic setup is forecasted, with a general dominance of low pressure over and just to the west of the UK anticipated in just a few days time

With the buildup of high pressure from the southwest, it seems like an end will come to a prolonged wet period. More settled conditions will prevail for the next few days over the UK. How will the wea

Well this week sees a large heat plume building over central & most of Western Europe,the UK however sitting on the western periphery with the trough anchored to the SW of us & southerly flow

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No change to the outlook for the rest of this week then with the all to brief warm up from tomorrow being replaced by the approaching low from the west bringing the cooler unsettled conditions for all by Sunday.

UKMO T120hrs-Sunday

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GFS for Saturday shows the change already into the west and north of the UK.

 

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the far SE just about holding on to the warmth until the day's end.

Looking further ahead into next week this appears from the ens outputs today to have all the makings of a stalling pattern as the Russian block holds firm to the east.

 

This would keep things showery with sunny periods as the trough remains in-stu near the Uk taking some time to gradually fill. 

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hmm some big differences between the GFS Op (right) and control run (left) this evening with the control going for a steady rise in the 850's from day 10 the driest weather always looks to be the further north you are

 

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One thing i struggle with as someone fairly new to model reading is knowing where the weatherfronts will be. Tonights ECM for example looks quite dry to me, but some posts above are saying some rain will be about.

 

I know that the fronts are where the airmasses meet, so as an example below, am i reading it correctly that the charts below from tonights ECM show a front to the north west of Scotland, along the green band?

 

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Just seen this Winter Cold-yep you pretty much got it.

Fronts on the fax charts are the boundary of the warm and cooler air masses along the Polar front.

I usually find the 850hPa charts show these up quite well.

If we compare the fax and the 850hPa charts below we can see this.

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see the frontal systems running along the 0C isotherm on the temperature chart.

 

Hope that helps.

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Just seen this Winter Cold-yep you pretty much got it.

Fronts on the fax charts are the boundary of the warm and cooler air masses along the Polar front.

I usually find the 850hPa charts show these up quite well.

If we compare the fax and the 850hPa charts below we can see this.

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.giffronts1.gifhttp:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.giffronts 2.gif

 

see the frontal systems running along the 0C isotherm on the temperature chart.

 

Hope that helps.

 

Top stuff :D

Thanks very much Phil, thats a good clear example!

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Looks like agreement on the trough over the UK has been reached, though the position of the low remains fluid, T144:

 

Navgem: post-14819-0-99602600-1400006082_thumb.p JMA: post-14819-0-42115800-1400006095_thumb.g

 

UKMOpost-14819-0-47899400-1400006105_thumb.g   GFSpost-14819-0-27151400-1400006132_thumb.p ECMpost-14819-0-26022500-1400006143_thumb.g

 

The GEFS are also variable on this count: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=144

 

No doubt its positioning will be a guide to the surface conditions.

 

Cannot fathom at the moment whether the trough will fill, mix or slide away, following the seemingly inevitable pressure rise in our locale showing in the GEFS FI. There are lots of spread and various clusters. Though around D12 appears the tip point for about 50% of the GEFS for that pressure rise, predominantly from a Scandi High cluster, then the AH ridging NE. 

 

As we would expect the Atlantic is asleep throughout FI, so plenty of opportunity for a HLB to build in-between the declining slack flow of the PV.

Might be more lucky next time and get some of the hot temps Eastern Europe will reach next week:

 

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Out to T+168 there is general consensus of a cyclonic spell of weather, so some warm sunshine to be had but there will be some heavy slow moving showers, so a convective outlook is likely... :closedeyes:

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It looks like turning unsettled by sunday across most areas, the southeast corner being the last place to see the change but in the meantime, becoming very warm with a lot of sunshine and light winds for the south of the uk and especially the southeast where temperatures look like soaring into the low to mid 20's celsius, around 75 F and perhaps a notch higher in and around london on saturday, progressively cooler and more unsettled the further northwest you are, especially for n.ireland / n & w scotland and the isles but with occasional fine spells.

 

The Ecm 12z op run shows a trough swinging southeast from greenland / iceland and sliding just to the west of the uk but gradually taking control of our weather with a growing risk of showers, heavy, thundery and slow moving but with warm sunny spells too, quite a cyclonic looking outlook for next week with sunshine and heavy showers and longer periods of rain, cooler when it rains but warm in the sunny spells. :)

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The ECM Anomaly has a deep pool of cold air centred just to the west of the UK with the intense high to the east next week A situation that is almost stationary for the time. Equally the surface cyclonic weather is the same Giving unsettled conditions with average temperatures

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Edited by knocker
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The ENS means. The ECM has the cold air somewhat deeper and more east with the GFS giving a glimmer of hope that the high pressure will infiltrate.

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Edited by knocker
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Well I wasn't expecting this from the GFS, a shift west

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Sunday and Monday would be warm, especially in Eastern areas if this came off.

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Given how small shifts west or east can greatly effect the surface conditions, getting anything beyond Saturday still looks to be difficult.

 

In the more reliable timeframe, some talk from the metoffice/BBC about showers on Saturday, GFS showing some decent cape for the late afternoon.

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Could get some decent storms. There is also a risk of isolated showers/storms on Friday as well though lower than Saturday.

 

Interestingly the NAVGEM also corrects west.

Edited by Captain shortwave
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The Met office are going with an unsettled outlook once the fine spell ends by sunday night across the south and east, much sooner than that for the north and west. With a large complex trough dropping anchor to the southwest of the uk next week, the west and especially the southwest are likely to see the most persistent rain and potentially stronger winds but for most of the uk it looks showery, most on the heavy side with thunder but with decent sunny spells and feeling warm.

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The Met office are going with an unsettled outlook once the fine spell ends by sunday night across the south and east, much sooner than that for the north and west. With a large complex trough dropping anchor to the southwest of the uk next week, the west and especially the southwest are likely to see the most persistent rain and potentially stronger winds but for most of the uk it looks showery, most on the heavy side with thunder but with decent sunny spells and feeling warm.

 

I think that also shows that low pressure does not fully mean it will turn significantly cooler, in any sunny moments, temperatures could still be around average if not above. Although it does look likely low pressure will become more of an influence, there is not too much out there to suggest the trough will park itself right over the UK but its certainly a possibility. 

 

On a side note and in relation to Karyo's status, look at all that hot air over Russia and potentially later on into Scandinavia, absolutely ridicules for this time of year, could be another hot and dry summer there? 

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Latest GFS shows it staying fairly warm with low pressure system staying out to the north west allowing warm air to move north. Later another low pressure system develops over Spain keeping the warm feed going. Some showery rain around but looking better than previous runs.

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My god where did that gfs run come from!!big changes in just a short time frame!!very warm and humid will be the standard over the next week if gfs is right!!ukmo slightly further west and south but still more unsettled!!just when we thought we saw model agreement!!

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Well all change. The train standing at platform five is the 00z GFS to “that fooled youâ€.

 

The 500mb anomaly on the18z run has the centre of the trough well to west of Scotland with the Scandinavian high reaching its tentacles into the North Sea. Spot the difference with the 00z run leading to a somewhat different evolvement of the surface analysis. The net result of this, in summation, is that high, or very high temperatures will persist at least until Wednesday with Tuesday showing temps in the high 70s.

 

What are the synoptics?

 

Saturday

A low SW of Iceland and a transient high over the Scilly Isles and the UK in an area of slack pressure except for northern Scotland that is in the SW flow from the depression.

 

Sunday

A complex area of low pressure NW of the UK bringing SW winds to the west with the east under the influence of a southerly from the high pressure to the east. The front is lying western Ireland to Stornoway, Art the same time the UKMO has the low west of Ireland with the front from Stornoway to Cornwall.

 

Monday

It’s as if Tommy Cooper has appeared. The low to the north west has relocated way NE of Iceland.leaving a slack area of low pressure stretching from northern Spain to the UK with the east, just, still under the influence of the high.

 

Tuesday

The low to the SW of Cornwall has deepened to 994mb with a frontal trough over Cornwall and generally SE unstable conditions to the UK.

 

Wednesday

The low now over the Bristol Channel with another low developed near NW Spain. Again a light SE and mainly dry.

 

At this range hopefully the models will be singing from the same hymn book but don’t hold your breath.

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Edited by knocker
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Even ecm has the low backed further west at 96 hours and very similar to the gfs and not the ukmo!!Although I know eventually that low will come across us but if it gete delayed there is better chance of things going wrong for the good hopefully!!

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I think the nail fell out last night  :rofl:

Decent agreement on trying to get low heights south west of the UK, the Euros going for low pressure close to South west England whilst the American models have the low further south in the Bay of Biscay. All output suggests warm weather for the start of next week with temperatures in the low/mid twenties. Question is how unsettled will conditions be. 

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Mean 850 temperatures for my area have gone from +1/2 to +8 in 12 hours. Enough said really.

 

I must add kudos to the GEM, it never really backed down from this scenario (if of course this is the right solution)

Edited by Captain shortwave
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UKMO this morning at t144 showing +8 850's in the SE at t144 (t120 850's currently not updated) away from the west  and Scotland Tuesday looks like another warm day though unsettled

 

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ECM however is much warmer for all at t144 looks pretty wet in parts of the west

 

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GEM remaining consistent from previous runs by also keeping the warm air in place at t144 GEM keeps it mostly dry

 

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And finally GFS also keeps the warm air over the UK on Tuesday

 

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So this morning its UKMO which is on its own for the 850's with all the rest going against it

 

 

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Fwiw, the spreads on ECM ens yesterday had the track of the lowest heights where the op takes them on the 00z.

Don't make the mistake of only looking at the heights and ignoring the surface pressure. Looks impossible to avoid the rainfall next week, even though temps may be reasonable

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Yes, The GFS this morning is showing some very warm Spring-like Temps from Friday through until Tues.

 

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Yes PM it's looking FAB-U-LUS

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