Model Output Discussion - Spring Has Sprung

[claret047]

 bluearmy We had snow here in mid Essex without height. Start to Cricket also delayed at Colchester's Castle gfound.

Edited February 19 by claret047

[Dennis]

winter ?

Edited February 19 by Dennis

[Anthony Burden]

Morning all,Charts firming up on a possible cold March with cold rain and snow in the mix pity that early February was not showing the same as March,still I’m afraid spring will be held up for sometime yet overcoat and gloves will be needed so keep them out after this very mild / mild spell is over.

[Jordan S]

A fairly quick post from me today, just explaining this low expected to make an appearance in the vicinity of the UK this weekend, it’s interesting how consistent GFS is with this southerly tracking low pressure system raising an eyebrow with a low probability of mainly high ground snowfall over central and southern areas of England for this weekend.

Midnight output..

This mornings output..

The system barely effects the UK and is across France with this output, while the upper air temperatures don’t look low enough for snow generally away from much higher ground here..

the lowering heights,

it being after sunset and precipitation intensity being high shown as brighter greens/yellows over parts of France on the northern flank with a northerly element to the winds away from the strong winds on the lows southern flank,

makes a big difference and would bring the freezing level much lower than areas of lighter precipitation around it which don’t trigger the evaporative cooling process to such a degree, less wind aswell means less mixing of milder upper air temperatures to the south and would bring temporary low level snowfall and limited significant high ground accumulated snowfall, why am I mentioning this if it’s over France? Because some models showing heavy wintry precipitation moving over southern areas from the low, so it’s easy to envisage that the same/similar scenario would play over southern UK (limited temporary significant accumulation on high ground such as Chilterns/Cotswolds) for example with temporary low level snowfall with patchy slight accumulation to areas away from major cities ie London with strong winds around the south and southwest coast of England. Though a thaw would take place once the precipitation clears as no deep cold around for example.

The track of the low obviously in question and that scenario although synoptically being shown at times, is unlikely but was interesting to point out.

The Ecmwf output for the low is more realistic. Low sweeping southeast over central and southern areas next weekend bringing a spell of rain, perhaps fairly heavy in places and possibility a bit of local hill snow in a few spots, then exiting into France.
 

Both Gfs and Ecmwf synoptically similar especially being 6 days out but details much different as you would expect.

 

Another low swings south east too afterwards. 

Edited February 19 by Jordan S

[Met4Cast]

The idea of blocking during March certainly isn't without merit and for those chasing some early spring warmth (like me) the direction of travel is rather poor. 

The MJO looks likely to return to phase 5/6 before the end of the month if we look at the VP200 anomalies (RMM plots are all over the place currently, some support this idea, some don't). I wonder if this is SSW related? 

An uptick in +EAMT is expected thanks to a strengthening East Asia jet stream and we're currently seeing the highest amount of +ve westerly momentum since early December, this shown by the GWO plot being the highest of the season so far. 

With the current SSW helping to destabalise the polar field combined with another likely weakening/possible reversal (maybe final warming?) early-mid March the idea of an increasingly -NAO regime seems to be the best bet currently. 

[bluearmy]

Update on the early March reversal shows less appetite for a split and most runs show a v marked displacement - the 06z manages to displace the spv at 10 hpa across the U.K.!  

[Rain All Night]

Just now, bluearmy said:

the 06z manages to displace the spv at 10 hpa across the U.K.!  

I assume we would not actually notice any direct effects from the SPV being directly above us?

[RJBingham]

first couple of week of march, not looking too bad 

 

 

Edited February 19 by RJBingham

[bluearmy]

 Rain All Night unlikely 

lower down is centred further northeast 

[Purga]

A cool dry easterly with no teeth - could be worse I suppose but hardly exciting.

[Purga]

 RJBingham  "not looking too bad" ? Depends what you're looking for. Snooze fest?

[Frigid]

 RJBingham Agree, only 1C above average. In other words, nice and cool.. much cooler than the mild spell we've been having 

[Dennis]

next weeks charts have some attention on poss snow 

 

Edited February 19 by Dennis

[Catacol]

2 hours ago, Met4Cast said:

The idea of blocking during March certainly isn't without merit and for those chasing some early spring warmth (like me) the direction of travel is rather poor. 

The MJO looks likely to return to phase 5/6 before the end of the month if we look at the VP200 anomalies (RMM plots are all over the place currently, some support this idea, some don't). I wonder if this is SSW related? 

An uptick in +EAMT is expected thanks to a strengthening East Asia jet stream and we're currently seeing the highest amount of +ve westerly momentum since early December, this shown by the GWO plot being the highest of the season so far. 

With the current SSW helping to destabalise the polar field combined with another likely weakening/possible reversal (maybe final warming?) early-mid March the idea of an increasingly -NAO regime seems to be the best bet currently. 

A sound summary and makes a lot of logical, teleconnective sense...but I'm not sure it will come to pass now and I'm ready to hang up my snow boots and depart this forum for another year. The vortex has refused to crack all season whatever the record books will say about a double SSW season, and predictions of a blocked February drained away all too quickly. Unless the vortex splits - which it now looks like it wont - then we are left with a weak and wobbly westerly vortex, not much of a downwell of any supportive reverse flow, and pacific forcings that will need to produce output that has not come to pass through most of this season. I can see the jet whipping up, and in theory with such a strong uptick in the GWO it ought to promote cold blocking....but I have a feeling that transient cold phases and a lot more rain is where we might end up.

It has been a fairly sapping experience over the last 6 weeks. I fear that the impact of CC is skewing everything in the wrong direction faster than many expected (just look at Alpine temperatures, Moroccan temperatures and the jaw dropping speed of ocean warming) and UK winter is going to get shorter and more scarce. For mid February our own temperatures have been fairly extreme. 

Meanwhile summer approaches and I am dreading how much heat may come with it. Perhaps something significant can shift next winter so that the patterns and the accompanying temperatures can give snowball players more of a chance.

[Met4Cast]

13 minutes ago, Catacol said:

Meanwhile summer approaches and I am dreading how much heat may come with it. Perhaps something significant can shift next winter so that the patterns and the accompanying temperatures can give snowball players more of a chance.

Agreed re: Cold/snow likelihoods, I think we will see a -NAO return but I’m not confident on that translating to a winter wonderland, like you it will probably be more chilly rain. 

On the quoted part though - I agree re: Summer, this perpetuating Iberian high pattern going into summer wouldn’t be good, Spain is already drought stricken & soil moisture is rapidly drying up now, I can definitely see scope for yet more record breaking temperatures across southern Europe this summer, especially when you factor in the declining El Niño & associated lag with the AAM as we transition into La Niña (probably sometime around mid summer). 

Early indications of summer patterns don’t bode well. 

[Downburst]

Ah yes, good news on the possible more settled and sometimes maybe even dry March becoming more evident. Like to see those +NAO kept nice and low. Who will get the first touch of a sun burn? won't be long. 

 

[pdiddy]

 Rain All Night it can lead to interesting cloud formation

[bluearmy]

Icon finds a mid Atlantic high as opposed to a mid Atlantic ridge 

 

[bluearmy]

 pdiddy doesn’t always correlate to the lowest temps high up.  Infact the 06z op has lower strat temps in the next few days than when it drifts the 10hpa spv  across us 

[Dennis]

Icon12z

[Catacol]

50 minutes ago, Met4Cast said:

Agreed re: Cold/snow likelihoods, I think we will see a -NAO return but I’m not confident on that translating to a winter wonderland, like you it will probably be more chilly rain. 

On the quoted part though - I agree re: Summer, this perpetuating Iberian high pattern going into summer wouldn’t be good, Spain is already drought stricken & soil moisture is rapidly drying up now, I can definitely see scope for yet more record breaking temperatures across southern Europe this summer, especially when you factor in the declining El Niño & associated lag with the AAM as we transition into La Niña (probably sometime around mid summer). 

Early indications of summer patterns don’t bode well. 

100% agree. I felt like a tipping point was reached about 4/5 years ago - sudden and obvious increase in summer heat-related incidents and misery and the rate of acceleration is stark. My Mum claims it is all media inspired...we think things are worse because more people talk about it and more pictures are taken - but while I'd like to think that's true, from a personal (and admittedly anecdotal rather than rigorously evidenced and fact collated) perspective we are heading into difficult times. I think Europe in particular is heading for very tough times, and maybe in 10-20 years we will be mighty glad of our atlantic blanket helping keep away the worst of things (despite its constant destruction of our winters!)

It's hard not to be gloomy about it all. Keeping this thread-relevant, a summer heat dome wont be far down the line. Should help May be lovely. But June-August? Too hot for me.

Edited February 19 by Catacol

[Rain All Night]

 bluearmy

Update: GFS and GEM don't look like this, they're just regular topplers

Edited February 19 by Rain All Night

[Metwatch]

One of the best endings i've seen to a GFS run in a long while in fl, this would be so welcome. Is it too much to ask for?

[damianslaw]

 It feels most have left this thread in there droves over past week or so.. perhaps unsurprising given how static the outlook has been.. but we are seeing changes ahead firmly in the reliable.. with the azores/iberian high kicked into touch by the deep atlantic trough set to make a landing over the UK through second half of the week.

Very unsettled in a word and feeling alot colder than of late by Thursday thanks to chilly NW winds and rain, on northern high ground perhaps a lot of snow before the week is out.

UKMO shows the trough dropping SE with a cold ridge following in behind by this time next week, GFS maintains the unsettled chilly theme with further low pressure systems tracking in from the NW.

Those who like calm quiet weather won't be enthralled by the outlook rest of the week, those who want lively bouts of wind/rain and sharp temp drops in showers will be happy as polar maritime air takes over, notable by its absence much of the winter.

 

[damianslaw]

 Metwatch Pleasant to see if you want early spring sun and warmth. Early March I feel may deliver something either cold and settled, mild and settled, cold and wet or mild and wet, frankly it could do anything..