Model discussion - March drawing to a close

[Mike Poole]

Precipitation including snow (white hatches) for the start of April courtesy of the FV3:

Given the models propensity for overdoing the cold, probably at the snowier end of possibilities.  But maybe the last chance to see a flake or two for many of us.

Edit, you have to click on it.

Edit, maybe you don't, seems to load OK now!

Edited March 31, 2019 by Mike Poole

[Frosty.]

Looking at Hirlam 12z I can just about make out a tiny blob of snow at T+48 hours across southern scotland.I'm green with envy  .don't think I will bother waxing the sled!!

Edited March 31, 2019 by Frosty.

[ANYWEATHER]

Evening Cold is the outlook.. anything past T+120 is a total waste of time...

[Mike Poole]

Notwithstanding above post, here's the CFS on June.  Pointless looking at one run of the CFS (it needs to be considered probabilistically), so here's the last 8 Z500 anomalies for June:

This far out, looking very promising for a decent summer, consistent with GloSea5 as far as I can see, maybe an indication that high pressure may dominate but not have it all it's own way as last year - potentially more thunderstorms? Last year was very quiet on thunderstorms in the summer months.  Let's see how things develop as we get closer to summer....

Edited March 31, 2019 by Mike Poole

[Frosty.]

Looking at tonight's Ecm 12z ensemble mean, the week ahead becomes trough dominated with below average temperatures with a mix of sunshine and April showers and some more persistent rain in places, even cold enough for some hill snow too, perhaps to modest hills but then towards day 10 the trough influence decreases significantly and pressure rises in connection to the scandi height rises, as for the temperatures, they start to rise too..slowly!

[Mike Poole]

ICON 18z at T63:

Reet northerly plunge...lack of precipitation on the charts, yes, but with the unstable flow, should be some convective element to the precipitation, not likely to be picked up on the global models, await the mighty HIRLAM tomorrow.

[Mike Poole]

Pub run going with the trend to make more of this cold outbreak, here at just T66:

How much precipitation goes with that we wait to see, but it seems to look more potent with every run at the moment, fascinating to see what actually happens....

[knocker]

Outlook - becoming unsettled for the rest of the week with the UK under the auspices of an upper trough resulting in a complex area of low pressure residing over us which will also bring with it much cooler weather and some strong winds at times

The NH 500mb profile (the aforementioned trough is east of southern Greenland) and the Atlantic analysis for midnight and the 0500 UK chart

As can be seen quite a chilly start to the day in most places, and with clear skies, which will remain the case for the rest of the day and getting quite warm in southern regions. But cloud with patchy rain from the front(s) associated with the trough is already effecting the north west and these will track south east through the day resulting in much colder day in northern regions

A continuation of this through this evening and overnight with the cold front Humber > Cornwall by 0600 with frequent wintry showers in the colder air behind the front

The cold front clears the south east by midday on Tuesday but by now the upper trough as descended south east over the UK and the associated surface low with a little wrap around occlusion is just west of Scotland  The result of all this is a much colder day with frequent wintry showers, particularly in north western and western regions in the very unstable air. And example of this below vis sounding and convective cloud heights

This scenario will continue overnight into Wednesday morning but the showers more likely more confines to western regions in the quite brisk northerly wind, coalescing in the troughs and convergence zones embedded in the flow

But by midday Wednesday a wave has formed on the old cold front and is in the North sea and this with the associated occlusion could bring a more concentrated area of rain into the north with perhaps some snow on the high ground in the north. Still quite windy down western coastal regions with showers and another cold day generally

Over Thursday and Friday low pressure remains in situ, boosted a tad by another trough dropping in from the west, whilst the subtropical high to the south west starts ti ridge strongly north east. Thus sunny intervals and showers but beginning to warm up a tad by Friday.

[Frosty.]

Looking towards Easter the GEFS 00z is very interesting, there's some real eye candy both in terms of southern warmth and northern cold, the duality of spring in all it's glory.

Edited April 1, 2019 by Frosty.

[knocker]

Looking further than the short range the ecm continues to indicate the pattern change that has been suggested recently. to whit pressure rising to the N/NE and low pressure to the S/SE with a conduit north west to Canada. Thus the UK in a slack easterly gradient, with little precipitation and temps close to normal, perhaps a tad below/

Edited April 1, 2019 by knocker

[BlueHedgehog074]

Can’t believe it’s April today and it’s not even noon yet.

The real GFS and ECMWF (those runs you guys have seen this morning are fake ), do not show a cold outlook at all this week. It does still have a flow from the North-West and North tomorrow and Wednesday, but the 850 hPa temperatures are around 0*C for the whole U.K. Totally inadequate for showers to be wintry, except over Knockers house, where there will be an isolated cold patch of -10*C hPa’s. The showers will only be light tomorrow, Wednesday and Thursday, again with the exception over knocker’s house where he’ll have frequent heavy snow showers. That isolated -10*C hPa patch not moderating over his house until Friday. By the weekend the real GFS and ECMWF show a ginormous European High developing to our East with extremely warm air getting sucked up from the South-East. It will stay very warm (possibly even hot at times) and sunny from the weekend and this will continue for all of next week with that mega powerful European High influencing the whole U.K.

Then, these models show that the European High will pull into the Atlantic and quickly take a big snooze over Greenland with a super cold unstable Northerly breaking through the U.K. 850 hPa temperatures ranging between -10*C to -12*C’s for the the U.K. Trough and disturbances in the flow will generate frequent and, at times, torrential snow showers with everywhere getting a 3cm+ covering. Right towards the end of the runs, the European High comes back. A hot and dry finish for the U.K. A thundery breakdown looming at 384 hours. 

That’s what the weather will be like for the next 2 weeks...

[knocker]

Not that easy to pin down the changing evolution a the moment although there certainly doesn't seem as if anything untoward is lurking in the woodshed.

Over the last three days the ext EPS has moved gradually to an intensification of the trop vortex over northern Russia with a link to the subsidiary over northern Canada,  At the same time the slack area of high pressure over northern Europe extends north west across the Atlantic to Greenland with the negatively tilted trough still to the south of this in the NW Atlantic with a conduit to the low pressure in southern Europe

Ergo, with the westerly upper flow diverted north and south courtesy of the above,, much inertia in the eastern atlantic with a very slack gradient over the UK. This portends a quiet period of weather with temps around average, perhaps a tad below.

And last evening's NOAA is in the same ball park

 

 

[Frosty.]

Beyond this week's trough dominated and unseasonably cool spell the Ecm 00z ensemble mean improves, less troughy, more ridgy in association with the scandi height rises.. so, signs it will eventually become drier with temperatures slowly recovering further south from approx the weekend / early next week onwards.

[SLEETY]

6 minutes ago, Frosty. said:

Beyond this week's trough dominated and unseasonably cool spell the Ecm 00z ensemble mean improves, less troughy, more ridgy in association with the scandi height rises.. so, signs it will eventually become drier with temperatures slowly recovering further south from approx the weekend / early next week onwards.

Imagine having that ensemble mean in january,this place would be buzzing instead of everyone  gone,apart from the posters who stay all year Pointless at this time of year unless you can get exceptionally cold uppers moving down from the NE .I guess their is a chance?

[BlueHedgehog074]

1 hour ago, Iceaxecrampon said:

ZZZZZzzzzzzz

I’m confused, lol

Sorry, it’s probably me being stupid.

Edit: I just hope you meant that in a jokey way (otherwise I’d admit I would find that insulting).

Edit part 2: Sorry I just get really sensitive sometimes and shouldn’t take things so personally.

Edited April 1, 2019 by DiagonalRedLine

[Methuselah]

Showers for us -- but will it snow in the Azores?  

[Methuselah]

I get the feeling that we may find ourselves in no-man's-land for a fair old while?

[knocker]

Interesting 0900 geostationary showing 'our' trough west of Iceland and the cold front west of Ireland

Edited April 1, 2019 by knocker

[Frosty.]

9 minutes ago, Ed Stone said:

I get the feeling that we may find ourselves in no-man's-land for a fair old while?

I don't mind, light winds and some sunshine = very pleasant

sad smiley alert

Edited April 1, 2019 by Frosty.

[Polar Maritime]

A few posts have had to go, Please use the Pm system for anything other than Model Discussion.

Thankyou all, Please continue.

[Methuselah]

Certainly the models are pointing toward a drier regime setting-in...but, how warm it'll be is much more in doubt.

 

[Frosty.]

Stuff high res charts. I like to dream it might snow!!!!

[Methuselah]

7 minutes ago, Frosty. said:

Stuff high res charts. I like to dream it might snow!!!!

When the day eventually comes (personally, I don't believe it ever will) when weather-models are 100% accurate, even out to 384 hours, I will most probably be six-feet under; even if I'm not, I'll be neither viewing nor posting in this thread...life will indeed be very boring!

[Polar Maritime]

By Thursday we will have -7/8/9 uppers over the UK with a pretty unstable flow from the NNW.

[Frosty.]

1 minute ago, Ed Stone said:

When the day eventually comes (personally, I don't believe it ever will) when weather-models are 100% accurate, even out to 384 hours, I will most probably be six-feet under

That would indeed be a Grave situation Ed