Model discussion - March drawing to a close

[damianslaw]

Northern blocking alert! easterly flow from the weekend onwards, all preety normal for April. Next week a balance between a flow from the SE or a much colder flow from the NE , with low pressure anchored down to the SW.

I suspect we will maintain a more direct easterly flow, with frontal activity to the SW coming unstuck against the block, meaning a very dull outlook for the east, sunniest driest weather in the NW, locally wettest weather in the SW, temperatures a bit below average in the north and east, possibly something milder for the south.

In the short term - high chance of snow to lower levels come morning in S Scotland and far N England and a cold day ahead, these areas may struggle to get above 5 degrees.

[Frosty.]

5 minutes ago, Frosty. said:

Stunning Ecm 12z ensemble mean..what an Easterly!!

That's what I was really hoping to say in Jan / Feb during the winter that never was!!..maybe next time eh coldies

[Mike Poole]

Here's the ICON 18z at T45:

We know how this will evolve from the other runs, but to get this to happen in winter?  Is it really too much to ask?  Seems that it is in recent years.  State of play: we seldom get memorable winters, we still get memorable summers, sporadically.  And in my view we will get another memorable summer this year....

Edited April 2, 2019 by Mike Poole

[MATTWOLVES 3]

21 minutes ago, Mike Poole said:

Here's the ICON 18z at T45:

We know how this will evolve from the other runs, but to get this to happen in winter?  Is it really too much to ask?  Seems that it is in recent years.  State of play: we seldom get memorable winters, we still get memorable summers, sporadically.  And in my view we will get another memorable summer this year....

Hopefully your are proven correct Mike, personally I'm less confident than you, but I do however think there will be several very warm spells. And regarding winter I personally feel we are very close to a memorable one... SSWS will become much more frequent in the years to come, we have endured 2 huge back to back ones already! And the states and Canada won't keep kopping it everytime! Sooner or later a vortex will drop right over scandy... 3 cheers for interesting times ahead!

Edited April 2, 2019 by Mattwolves

[Mike Poole]

Your point about SSW events  ^ is well made I think, Matt. I also expect these to become more common in coming years, but I also think that our chances of wintery synoptics in the absence of SSW events will reduce.  So for weather watchers in here, more nail biting while we watch over weeks whether a SSW will take place and if it does will it benefit the UK. 

Re summer, I'm more confident, GloSea5 is on board as it was last year, possibly more so.  GWO looks like supporting high pressure from mid month, so relax.  

Back to the now, I even saw a snowflake and some hail today!

Edited April 2, 2019 by Mike Poole

[MATTWOLVES 3]

8 minutes ago, Mike Poole said:

Your point about SSW events is well made I think, Matt. I also expect these to become more common in coming years, but I also think that our chances of wintery synoptics in the absence of SSW events will reduce.  So for weather watchers in here, more nail biting while we watch over weeks whether a SSW will take place and if it does will it benefit the UK. 

Re summer, I'm more confident, GloSea5 is on board as it was last year, possibly more so.  GWO looks like supporting high pressure from mid month, so relax.  I even saw a snowflake and some hail today!

Good post Mike, I see your point regarding SSW events being required to bring us the wintry sypnotics... Would be Interesting to know how many times in past severe winters that SSWs were responsible! Especially has little was known about them back in the 70s and 80s! Solar minimum could also come to our rescue in the next few years, this could be very beneficial regarding the weakening of the Atlantic jet hopefully leading to more in the way of HLB. Now if we can have one of these SSWs to land in the right place, coupled with solar minimum..... Then boom, it really could be a winter to remember. What you say about summer Mike is valid, I know the atlantic is sluggish at this time of the year, but tbh, it has been all winter! And come to mention it, most of last year to! This can only serve to multiply high pressure scenarios again this summer... If the atlantic is gonna remain in slumber, then indeed the summer could be very tasty Indeed! And perhaps Mike, solar minimum as we speak may also be responsible for a very sluggish jet! Like I said earlier interesting times ahead....

[Mapantz]

Back to the models, please. 

[knocker]

The Atlantic surface analyses and the Camborne sounding for midnight and the 0400UTC UK chart

The sounding above illustrates very well the cold, unstable, air currently over the UK with a 500mb temp of -36.5C and tropopause around 20, 000ft. Ties in very well with the frequent heavy showers currently over the south west peninsula with forecast cloud tops around the tropopause.

These should become less heavy and frequent through the morning but the main action is further north. A large area of rain, sleet and snow (moderate in the Carlisle area at the moment) is currently effecting all of central and eastern Scotland and the north west of England. This band, becoming mostly  of rain, will tend to move south west within the circulation of the low as it tracks down the country to be over Wales by midnight. The movement of the low will briefly bring some strong winds to western Scotland

Through the night bands of rain/snow will continue to effect the country courtesy of troughs/fronts within the general circulation but mainly concentrated in the south west and north east.

Tomorrow a band of heavy rain will track west across Scotland with frequent showers continuing in the south west, otherwise sunshine and far less frequent showers in other areas.

Over Thursday night and through Friday the complex trough continues to dominate the UK weather with various troughs and fronts around but still much of the precipitation around the south west and north with a few showers and sunny intervals elsewhere. But the trough is slipping south west as the high pressure ridges into northern Scandinavia. Warming up a tad

Over the weekend the trough becomes established over Europe with the high consolidating to the N/NE resulting in relatively light easterly flow over the UK so generally drier but with a fair bit of regional temp variation, but still some showers around in the SW and N initially and possibly along the east coast on Sunday as a frontal system slips west along the southern flank of the ridge.

 

[knocker]

To continue briefly with the gfs. The frontal wave continues to track west, and phasing with the trough to the south west, bringing some showery weather through Monday/Tuesday with the easterly winds veering somewhat and mainly effecting the north east. Temps a little below average.Over the next 48hours the easterly regime once once becomes more general with temps below average and perhaps the showers more likely in eastern coastal areas and the south of England and Wales

[SMU]

ECM day 7 adds a bit of spice from the East...

[seabreeze86]

ECM is very cold and potentially very wintry with a bitting cold wind. Certainly wouldn't feel much like April 

[Frosty.]

Epic Ecm 00z, becomes very cold for the time of year.

Edited April 3, 2019 by Frosty.

[bluearmy]

Seriously ..... I mean it’s bloody April ..... where the hell were you two months  ago - decent neg AO/NAO combo.... 

not too late for a mid April wintry surprise across n England - we had one a few years ago and it was definitely memorable in the hills. 

[knocker]

The ecm has a front tracking west bringing some rain the south/south west on Sunday and also some showery rain Monday/Tuesday with low pressure quite adjacent to the SW > S > E as the center of the high cell is over Iceland  It is the orientation of the high pressure and the emery flows around it that appears to be the key here as can be seen by t168 with quite a strong easterly over the UK apart from Scotland with temps a little below normal

But then over Wednesday and Thursday colder air is advected in from one of the energy flows around the south east flank of the ridge with temps in some regions considerable below average.

Edited April 3, 2019 by knocker

[knocker]

One could say there is a fair difference with the 300mb wind fields by day ten in the last two ecm runs. Will they both be wrong?

[knocker]

After briefly transporting colder air into the UK the courtesy of the high cell over Greenland the ext EPS mean anomaly continues to suggest cutting off this supply, albeit temps still a tad below average

 

Edited April 3, 2019 by knocker

[Methuselah]

Having perused both GFS runs, I can find only this wee ray of hope; and, even then, it's too far out to take seriously...

We've spent the entire winter searching in vain for something cold, and now it's Spring, we can't get rid of it! Sod's law?

Edited April 3, 2019 by Ed Stone

[MATTWOLVES 3]

ECM AND GFS at 192hrs,both bringing the cold, but ECM more potent. Then beyond day 10 GFSP bringing potentially quite a warm up! 

[Frosty.]

You think it's cold now, next week could become even colder, accentuated by the strength of the Easterly winds, it would feel bitter even towards mid april..there's a milder blip for Friday into the weekend with winds more SE'ly before they swing Easterly and the colder uppers begin to march wsw... really exceptionally cold Ecm 00z operational / ens mean.

Edited April 3, 2019 by Frosty.

[SLEETY]

Ecm wasn't a cold outlier. Amazing. Watch it verify, of course if this was January then the charts after t144 which bring in the very cold air wouldn't happen of course!! 

[Methuselah]

Well, the upcoming weekend looks looks like being uncompromisingly dire!

[Frosty.]

Looking at the Gfs 6z operational next week doesn't look anything like as cold as the ecm becomes, indeed across southern uk it becomes pleasantly mild and gradually less unsettled.

[MATTWOLVES 3]

14 minutes ago, Frosty. said:

Looking at the Gfs 6z operational next week doesn't look anything like as cold as the ecm becomes, indeed across southern uk it becomes pleasantly mild and gradually less unsettled.

Looks like one of the models is well wide of the mark again, not for the first time this year I may add!

[MATTWOLVES 3]

47 minutes ago, Ed Stone said:

Well, the upcoming weekend looks looks like being uncompromisingly dire!

I wouldn't take that at face value Pete, the forecast for the weekend is looking more settled and warmer away from the coasts.

Edited April 3, 2019 by Mattwolves

[Methuselah]

Overall, a much better run IMO: gradually becoming warmer and more settled, with time:

  

Now watch as the FV3 puts us back into the freezer!