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Quantum
Monday, March 14, 2016 1:58:25 PM



A clear picture of the anomalies, with the neutral range in white, as should really be the case for all anomaly maps IMO.


The extent of the cold pool south is less than it was when I last looked in January, but otherwise it's still going pretty strong. It will be quite revealing if the late spring and summer patterns bear much resemblance to last year's.


Originally Posted by: Stormchaser 


The disparity is not a matter of scaling. Look in the baffin bay for example, warm anomoly on this map, cold anomoly on the other one.


Either there is an error on one of the charts or the methodologies are different.


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Edicius81
Monday, March 14, 2016 2:05:42 PM


 


For an idea, you can start by looking at the predicted precipitable water, which is good for an at-a-glance impression as to how much moisture will be available for cloud formation.


For example, the air is very dry across the south today, but higher precipitable water amounts move in from the North Sea by Tuesday, having already started to affect the northern half of the UK this afternoon. Satellite imagery this morning doe indeed show a veil of low cloud on the approach.


 


 


It's then a case of at what level - if any - does the atmosphere support cloud formation. 


Meteociel has a neat feature which allows you to create virtual 'soundings' of the atmosphere from WRF model data, at this link: 


http://www.meteociel.fr/modeles/sondage_wrf.php?region=uk&ech=1&mode=2&wrf=0


Just chose a time and then click on the map wherever you want to generate a sounding for.


I have picked two examples for the heart of England, the left one for today, the right for tomorrow. Unfortunately the images don't display clearly at all in terms of numbers so I can only really work with the fact that the red line is the air temperature, and the bright blue line is the dew point. The closer together these are, the closer to saturation - and potentially cloud formation - the air is.


 


 


For today's sounding, we can see that the dew point is a long way below the air temperature until very low in the atmosphere. This makes cloud formation unlikely except at very low levels - and this has been realised in the form of some radiation fog this morning with sparkling clear skies above.


Tomorrow's sounding tells a different story. High up in the atmosphere we can still see some dry air - which is a feature that high pressure brings, as dry air descends from aloft (known as anticyclonic dry air descent). Nearer to the surface, however, conditions are closet to saturated. Given that this is an estimated 'average' state, this suggests plenty of scope for cloud formation, but with room for some breaks as well, with some sunny spells coming through.


Right near the surface (lowest km of the atmosphere I think - the scale is so out of focus!) there is a totally saturated layer which could mean dense fog or (very) low cloud. So there is the risk of a thin shelf of near-continuous low cloud forming beneath a more broken layer of cumulus, the latter greatly limiting the ability of the sun to try and punch through the low cloud.
Whether a particular location sees that or not will come down to other variables such as how much vertical movement of air there is (e.g. turbulence) and whether there is high terrain upwind, which could hold up some or all of the low level moisture.


I'd not be surprised to see a shallow veil of low cloud plaguing areas east of the Pennines tomorrow, while to the west there is a cumulus regime with some sunny spells.


 


I hope this has proved an effective answer to your question, SFB - though I expect there's more to be considered (cloud formation is not my area of focus for the time being).


Originally Posted by: Stormchaser 


Exceptional post. Thanks very much.

springsunshine
Monday, March 14, 2016 5:29:04 PM

Just a hunch,from what the models are showing and the recent trend I have a strong feeling 2016 could turn out to be one of the coldest years on record.

Brian Gaze
Monday, March 14, 2016 6:15:10 PM

Continuing to look more changeable as we head towards Easter. If we get one of the colder outcomes hopefully there'll be some decent convection and big hail showers. 



Brian Gaze
Berkhamsted
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SJV
Monday, March 14, 2016 6:45:05 PM

Looks like we will have to make the best of the dry weather and sunnier spells this week, Brian. Nothing overly wet on the horizon, though. A cooling trend as March draws to a close though  Like you say Brian, there could be some big showers in those precip spikes 

Azza07
Monday, March 14, 2016 7:02:28 PM

ECM ends with a cracker. Can't post chart don't no how to 

doctormog
Monday, March 14, 2016 7:20:54 PM


ECM ends with a cracker. Can't post chart don't no how to 


Originally Posted by: Azza07 


Yes, it does look a bit chilly http://www.wetterzentrale.de/pics/Recm2401.gif


There does seem to be a cooling trend evident in the one week to ten day period and this has been evident for a few days now. 


Stormchaser
Monday, March 14, 2016 8:00:06 PM

Thanks Edicius 


- - - - - - -


Mysterious, those differences between the two SST anomaly maps that Q has pointed out. I have generally found the PSD variant to be reliable.


- - - - - - -


Turns out there's more disparity to be found between the model runs tonight, and from not that far out in time either;


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour. No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


Here, for day 5, we see considerably differences in how the rather complex situation with the areas of low pressure in the Atlantic is handled. GFS has merged two areas of low pressure into one just SW of Greenland, while ECM keeps them separate. Another difference is that GFS is faster and less amplified with the trough near the Eastern Seaboard.


Both of these differences tie in with a stronger polar jet in the GFS output and sure enough, we see GFS driving low pressure 'over' (passing to the north of) the UK high two days down the line, while ECM holds the lows out west and keeps the UK high in place:


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour. No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


Both models then respond to a signal for a trough to drop down toward Europe and/or Scandinavia, but the earlier flattening of the ridge leads to a very tame import of cold air from GFS (after which it again drives a westerly flow -it seems as if the model struggles to comprehend much else in the face of uncertainty). ECM, on the other hand, would have us wondering if it was late March or late February, the -10*C 850hPa isotherm en route for Scotland with an ETA of day 11, I expect. It's not hard to imagine a lot of clear blue skies with that setup, but also a few rounds of hefty showers with some hail and thunder for some parts. Temperatures possibly rising into the high single digits in the south where the sun's out, but in heavy showers falling into the low digits.


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour. No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


I have described this outcome because it seems the more sensible outcome to me given the recent/ongoing stratospheric events and perhaps a bit of MJO forcing. The idea of a westerly regime establishing (i.e. winds with a significant westerly component for more than a day or two) seems strange given how little support there's expected to be for polar vortex reformation.


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Quantum
Monday, March 14, 2016 8:26:20 PM

Some great 12Z ensembles.


Pertubation 5 has a potent northerly followed by an easterly and then threatens a reload. 



Pertubation 7 does something similar. Northerly -> Easterly -> Northerly.



Pertubation 12 has a persistent NErly covering the entire UK in cold air.



Perturbation 20 also has a persistent NErly and truly releases the beast right at the end of the run



These are my highlights, most of the charts are cold, but these are the ones bringing severe and long lasting cold spells. More than half bring cold spells of some description though with a mix of northerlies and easterlies on offer.


 


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Hippydave
Monday, March 14, 2016 8:58:14 PM

Not that'll make any difference to the outcome but I am rather conflicted about cold uppers at this time of year. On the one hand I do like to see snow, even if it's just falling. On the other, it is spring for gawds sake and I've spent the last 3-4 months cycling to work through dank, miserable rubbish (and some fairly chilly stuff lately too). It'd be nice to get some mild spring days in


Given what the models show I rather suspect there's going to be some more chilly weather to get through in the next week or two - even if the colder options don't materialise there's nothing to suggest any early season warmth sadly. (And yes I'm aware it'll feel warm in the sun and out of the wind!)


Home: Tunbridge Wells
Work: Tonbridge
Quantum
Monday, March 14, 2016 9:01:13 PM

Cooldown of the continent is pretty impressive



Scandanavia and the baltic is plunged into the freezer.


 


 


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Quantum
Monday, March 14, 2016 9:03:08 PM


Not that'll make any difference to the outcome but I am rather conflicted about cold uppers at this time of year. On the one hand I do like to see snow, even if it's just falling. On the other, it is spring for gawds sake and I've spent the last 3-4 months cycling to work through dank, miserable rubbish (and some fairly chilly stuff lately too). It'd be nice to get some mild spring days in


Given what the models show I rather suspect there's going to be some more chilly weather to get through in the next week or two - even if the colder options don't materialise there's nothing to suggest any early season warmth sadly. (And yes I'm aware it'll feel warm in the sun and out of the wind!)


Originally Posted by: Hippydave 


A potent northerly would create quite a different feeling at this time of year. Between the showers it could feel pleasantly warm, but during the showers you could be exposed to dramatic hail and snow showers (perhaps thundery). Perfect mix of wild summer and winter weather!


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Quantum
Monday, March 14, 2016 9:20:18 PM

What's left of the polar vortex actually seems to be locating to W russia. Highly unusual position for it to be. 



 


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Quantum
Monday, March 14, 2016 9:43:06 PM

Really quite an extreme chart



1050mb high in the central arctic and a very deep cold core low over western russia representing the remnants of the polar vortex. The tropospheric polar vortex is actually further south here than it was in 2010. If this was January there would be -40C uppers under that.


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Quantum
Monday, March 14, 2016 9:58:26 PM

Quite amazing to see that even cold pooling can happen at this time of year with each day colder than the last.



2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
some faraway beach
Monday, March 14, 2016 11:00:53 PM


 


For an idea, you can start by looking at the predicted precipitable water, which is good for an at-a-glance impression as to how much moisture will be available for cloud formation.


For example, the air is very dry across the south today, but higher precipitable water amounts move in from the North Sea by Tuesday, having already started to affect the northern half of the UK this afternoon. Satellite imagery this morning doe indeed show a veil of low cloud on the approach.


 


 


It's then a case of at what level - if any - does the atmosphere support cloud formation. 


Meteociel has a neat feature which allows you to create virtual 'soundings' of the atmosphere from WRF model data, at this link: 


http://www.meteociel.fr/modeles/sondage_wrf.php?region=uk&ech=1&mode=2&wrf=0


Just chose a time and then click on the map wherever you want to generate a sounding for.


I have picked two examples for the heart of England, the left one for today, the right for tomorrow. Unfortunately the images don't display clearly at all in terms of numbers so I can only really work with the fact that the red line is the air temperature, and the bright blue line is the dew point. The closer together these are, the closer to saturation - and potentially cloud formation - the air is.


 


 


For today's sounding, we can see that the dew point is a long way below the air temperature until very low in the atmosphere. This makes cloud formation unlikely except at very low levels - and this has been realised in the form of some radiation fog this morning with sparkling clear skies above.


Tomorrow's sounding tells a different story. High up in the atmosphere we can still see some dry air - which is a feature that high pressure brings, as dry air descends from aloft (known as anticyclonic dry air descent). Nearer to the surface, however, conditions are closet to saturated. Given that this is an estimated 'average' state, this suggests plenty of scope for cloud formation, but with room for some breaks as well, with some sunny spells coming through.


Right near the surface (lowest km of the atmosphere I think - the scale is so out of focus!) there is a totally saturated layer which could mean dense fog or (very) low cloud. So there is the risk of a thin shelf of near-continuous low cloud forming beneath a more broken layer of cumulus, the latter greatly limiting the ability of the sun to try and punch through the low cloud.
Whether a particular location sees that or not will come down to other variables such as how much vertical movement of air there is (e.g. turbulence) and whether there is high terrain upwind, which could hold up some or all of the low level moisture.


I'd not be surprised to see a shallow veil of low cloud plaguing areas east of the Pennines tomorrow, while to the west there is a cumulus regime with some sunny spells.


 


I hope this has proved an effective answer to your question, SFB - though I expect there's more to be considered (cloud formation is not my area of focus for the time being).


Originally Posted by: Stormchaser 


That is tremendous. It never occurred to me to use soundings as a proxy for cloud formation. But, of course, what are clouds other than the effect of condensation forming on dust and microbes?


Many thanks.


 


2 miles west of Taunton, 32 m asl, where "milder air moving in from the west" becomes SNOWMAGEDDON.
Well, two or three times a decade it does, anyway.
Quantum
Monday, March 14, 2016 11:04:24 PM

the 18z sure is entertaining. 


Netweather GFS Image


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
LA2B MeridFlowEuro09
Monday, March 14, 2016 11:33:44 PM

The Forecast 12z GFS and UKMO 12z for Europe divided between Normal to Slightly Above Normal in West and NW Europe, to well below March Normal for NW West Russia and East NE Europe away from Central. This Situation gets further Amplified- Pushing Cold Weather up the Aforementioned colder areas, this they say at least for next 144 hours.  The NW Atlantic and around Greenland the Thermohaline THC belt affects, at 120-168 hours ahead upto Iceland, while UK and Mid E Central N Atlantic to West Central Europe continue with included UK as well, at least upto Next Week Tuesday, then at 168-192hrs and 216-240 hours things tilt NW to ESE as Cold Weather from NE Canada and via NF and SE Greenland gets to affect UK and NW Europe next week in at least two phases Thursday Friday and then from day 13-14 Sunday Monday 25-26^ March etc.  These are GFS and ECMWF based predictions at the moment, though ECMWF shows it at 240hours.


It will be slightly above Normal to milder at 120 and 144, 168hrs as per today's GFS and ECMWF run, but I not view ECMWF today!!.


Amplification NE USA West and SE USA and North NE Atlantic with Areas of Mid Lattitude High's that have very mild air affecting some places in forecast day 0-14.  Very Warm very mild SE or Southerly flow in USA this March so far- it is also bringing Low Pressure and Strong winds for much of USA, with WAA S'ly SE'ly flows and also Cyclonic West to SW flows with much needed heavy rain and thunder showers, West USA at times very wet and chilly for the time of year- this happened upto now and started 5 weeks ago.


 


The MLB Mid N E N Atlantic High and Azores plus UK High and West NW Europe High will be facing more and more squeeze in about 5 days time ahem!😅😆.


Still some cold days for London this week Wednesday and Thursday thanks to cold air pooling under chilly stiff Easterly - then it settles down even here again, as yesterday + today been okay, still breezy day Monday, yesterday I think was light wind but was breezy cold on Friday-Saturday.


Climate is warming up, Scotland and N Ireland and North England still often gets some Winter frost, ice and snow, November to March, but the SE and South UK including S Central England and Wales, together with the West and North through the year, they sometimes get more rain than London and S SE England, where some longer dry fine spells without much heavy rain is seen every year.

The North Atlantic Sea often gets some much Colder Wintry conditions from November to March Months, and Mild SW and South winds tend to be more frequent over the East and SE of North Atlantic Sea, as the Azores High tends to stay in charge. 

With this warmth and heat, the Central and South UK has become mostly free of snow and frost.
Quantum
Tuesday, March 15, 2016 1:46:34 AM

fourth imagefourth image


Some of the potential being shown over the UK. 


2024/2025 Snow days (approx 850hpa temp):
18/11 (-6)

2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
GIBBY
Tuesday, March 15, 2016 8:40:50 AM
HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON TUESDAY MAR 15TH 2016

 


THE CURRENT GENERAL SITUATION Pressure will remain very high over the UK in the coming days. A weak warm front followed by a cold front will move West across England and Wales tonight and tomorrow.


http://www.wetterzentrale.de/pics/Rtavn001.gif


CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the UK will remain in the range of 6000-7000ft asl under strong High pressure bit the level may fall to around 5000ft tomorrow behind the cold front moving West. No snowfall is expected across the UK today.


http://www.snow-forecast.com/maps/dynamic/uk 


http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif 


MODELS-2 WEEK HEADLINE Mostly dry and bright with some frosts at night. Probably becoming less settled later in the month especially in the North.


THE GFS JET STREAM FORECAST  The Jet Stream remains blocked by a large High to the North and NE of the UK. The result of this is the flow is diverted both South and North of the UK before declining High pressure next week makes for a less defined pattern to the flow yet to be properly determined..


http://www.netweather.tv/index.cgi?action=jetstream 


GFS OPERATIONAL The GFS Operational Run today shows High pressure moving slowly West or SW from a point to the NE of the UK over and away to the West and SW of the UK all this time maintaining bright and fresh weather with sunshine at times and little or no rain. then as we move towards Easter a glancing blow at a chilly NW flow could bring a chilly period with a few showers towards the NE before milder SW winds but High pressure close to the South offers some rain in the NW while the South and east of the UK stay largely dry and bright with temperatures near average over the Easter weekend. 


GFS CONTROL RUN The theme of the Control Run shows the same High pressure moving West across the UK through the rest of this week and weekend with it's largely fine and settled conditions maintained. then as we move into the run up towards Easter the weather looks like turning more unsettled with some rain at times and a marked chilly day or so under a transient Northerly with some wintry showers in the east before milder air at times encroaches in and over the UK from the Atlantic towards the end of the month.


http://www.wetterzentrale.de/pics/Rtavn1441.gif 


http://www.wetterzentrale.de/pics/Rtavn3841.gif


http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0


http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0 


GFS ENSEMBLE DAY 14 DATA  The GFS Clusters today have now endorsed a more definitive pattern to be set up for the UK in 14 days time. Most members follow a Low pressure route now with it's centre somewhere near NW Britain with milder SW winds and rain at times in average temperatures the most likely scenario for the UK in two weeks time.


http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD= 


UKMO The UKMO model this morning shows High pressure on the move West and then South to lie across Southern areas by the early days of next week with a milder Westerly flow developing across the North. The weather looks like staying dry and fine for the most parts with a chilly breeze in the South and East dying down by the weekend.


http://www.wetterzentrale.de/pics/Rukm1441.gif 


THE FAX CHARTS The Fax Charts illustrate the High pressure 's movement West or SW over the North of the UK through the week. With the UK lying on the Southern flank of the High chilly NE winds are shown to drag weak troughs West in the flow at times each bringing increased cloud cover at times and more suppressed temperatures.


http://www.weathercharts.org/ukmomslp.htm#t120 


GEM GEM this morning looks very settled too over the next 10 days as High pressure slowly transfers from a position just to the NE of the UK to one just to the SW by next week extending a ridge across Southern Britain. This prevents the earlier projected cold plunge to affect Europe this far west and keeps temperatures respectable throughout the period especially given the increase of Atlantic Westerly flow across the North next week.


http://www.wetterzentrale.de/pics/Rgem2401.gif 


NAVGEM NAVGEM too looks very similar to the general theme shown by most output this morning with High pressure moving from a point to the NE to one to the SW of the UK by this time next week with largely fine and settled conditions continuing for all areas in temperatures close to average.


http://www.wetterzentrale.de/pics/Rnvg1681.gif 


ECM ECM this morning looks a little isolated as it is the only operational run this morning that still shows a cold Northerly or NW'ly flow across the UK as we move towards Easter though it is somewhat moderated from what was shown yesterday. Nevertheless after another week of fine and quiet weather next week would become chilly and unsettled as Low pressure is steered down from the NW or North with North and NW winds with rain and showers likely by then with snow on hills possible. 


http://www.wetterzentrale.de/pics/Recm2401.gif 


ECM 10 DAY MEAN The 240hr mean Chart has moved towards a less cold theme than it showed yesterday at it's 10 day time point as it now shows weaker Low pressure to the East and NE, High pressure well to the SW and a pattern of Westerly winds across the UK with some rain at times over the North. There are still a few members who continue to project a colder Northerly possible though this result has far less support this morning.


http://www.wetterzentrale.de/pics/Reem2401.gif 


NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The trend towards a cold and unsettled Easter has been lessened today with a more likely South/North divide looking most popular across the models this morning with the best weather retained in the South for Easter itself.


31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO at 99.5 pts and GFS at 99.4 pts.  At 3 days ECM is leading with 97.5 pts to UKMO's 97.1 pts while GFS lags behind at 96.3 pts. At 5 days ECM leads with 89.9 pts to UKMO at 89.1 pts and GFS at 85.7 pts. Then at 8 Days ECM has the leading spot from GFS with 64.3 pts to 60.0 pts. Finally at Day 10 ECM has regained the lead from GFS with a score of 45.7 pts to 44.8 pts.


http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png


http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png


http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png


http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png


http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png


MY THOUGHTS There are some changes in the output this morning regarding the period around Easter. I'll talk about those in a minute but for now the message is the same as was with High pressure in complete control of the UK weather. High pressure just to the NE is maintaining a chilly NE flow across the South with the best temperatures maintained across Western Scotland. Cloud amounts will vary and could be quite large for a time near the East coast and other areas too for a time tonight and tomorrow as some very weak fronts move West. Then as we move through the weekend prospects remain good with rather less breeze in the South as the High pressure moves slowly West and SW across the North to a position to the West of the UK. Then the general theme looks for the High pressure to slip South towards a point SW of the UK but maintaining a ridge across the South. This is where the differences come into play as the general message from the models appear to be for Westerly winds to take hold across the North perhaps with some rain while the fine weather holds on over the South. If this pattern continues to be shown then Easter could be a good deal milder than was shown yesterday with temperatures nearer to average and less chance of wintry showers. Nevertheless, ECM still shows a chilly theme under North winds up to Good Friday and it looks like this could be maintained for the rest of Easter too with a large blocking High over the Atlantic so all is not lost for those looking for a cold and showery convective period over the long holiday weekend. However, it should be noted that it's 10 day mean chart this morning has taken a step towards the majority of output in suggestion for a less cold Westerly rather than a cold Northerly looking increasingly likely for Easter. I'm sure we will see the picture become much clearer one way or the other in the coming days. 


Next Update Wednesday March 16th 2016 from 09:00


Martin G
Kilmersdon Radstock Bath Somerset



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David M Porter
Tuesday, March 15, 2016 9:48:20 AM


Thanks Edicius 


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Mysterious, those differences between the two SST anomaly maps that Q has pointed out. I have generally found the PSD variant to be reliable.


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Turns out there's more disparity to be found between the model runs tonight, and from not that far out in time either;


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour. No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


Here, for day 5, we see considerably differences in how the rather complex situation with the areas of low pressure in the Atlantic is handled. GFS has merged two areas of low pressure into one just SW of Greenland, while ECM keeps them separate. Another difference is that GFS is faster and less amplified with the trough near the Eastern Seaboard.


Both of these differences tie in with a stronger polar jet in the GFS output and sure enough, we see GFS driving low pressure 'over' (passing to the north of) the UK high two days down the line, while ECM holds the lows out west and keeps the UK high in place:


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour. No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


Both models then respond to a signal for a trough to drop down toward Europe and/or Scandinavia, but the earlier flattening of the ridge leads to a very tame import of cold air from GFS (after which it again drives a westerly flow -it seems as if the model struggles to comprehend much else in the face of uncertainty). ECM, on the other hand, would have us wondering if it was late March or late February, the -10*C 850hPa isotherm en route for Scotland with an ETA of day 11, I expect. It's not hard to imagine a lot of clear blue skies with that setup, but also a few rounds of hefty showers with some hail and thunder for some parts. Temperatures possibly rising into the high single digits in the south where the sun's out, but in heavy showers falling into the low digits.


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour. No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


I have described this outcome because it seems the more sensible outcome to me given the recent/ongoing stratospheric events and perhaps a bit of MJO forcing. The idea of a westerly regime establishing (i.e. winds with a significant westerly component for more than a day or two) seems strange given how little support there's expected to be for polar vortex reformation.


Originally Posted by: Stormchaser 


As I understand it, this is usually the time of year when the polar vortex starts to decline in strength somewhat anyway. The sun will be moving north to our side of the equator around a week from now and once that happens, it should be the beginning of the end for the polar vortex until we reach the latter stages of this year.


Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
Twister
Tuesday, March 15, 2016 5:13:43 PM

I spy some consistency between the GFS 6Z and 12Z runs:


- Today: High centred just to our NE
- By weekend: High moves to be centred just to the west of northern UK
- Next week: High sinks SW towards the Azores but ridging enough to allow a temporary northerly blast
- Next weekend: High pressure positioned to the south, allowing a more westerly flow across the UK.


The GFS Parallel (6Z) hints at more in the way of northern blocking and a little more unsettled with a risk of a cool zonal flow later in FI.


The UKMO hinting at possibly Atlantic blocking and a northerly flow earlier next week?


http://www.meteociel.fr/ukmo/runs/2016031512/UW144-21.GIF?15-17


 


Location: Egerton, Kent - 33m ASL
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Winter 2016/7: Snowfalls: 4 (Jan 12-3, Feb 10-11) | Snowcover: 2 (Jan 13, 2cm, Feb 11, 3-5mm) | Air frosts: 57 (2 in Oct, 10 in Nov, 13 in Dec, 19 in Jan, 6 in Feb, 3 in Mar, 4 in Apr)
"The heavens tell of the glory of God. The skies display his marvellous craftsmanship." (Psalm 19:1)
Ally Pally Snowman
Tuesday, March 15, 2016 5:59:25 PM


I spy some consistency between the GFS 6Z and 12Z runs:


- Today: High centred just to our NE
- By weekend: High moves to be centred just to the west of northern UK
- Next week: High sinks SW towards the Azores but ridging enough to allow a temporary northerly blast
- Next weekend: High pressure positioned to the south, allowing a more westerly flow across the UK.


The GFS Parallel (6Z) hints at more in the way of northern blocking and a little more unsettled with a risk of a cool zonal flow later in FI.


The UKMO hinting at possibly Atlantic blocking and a northerly flow earlier next week?


http://www.meteociel.fr/ukmo/runs/2016031512/UW144-21.GIF?15-17


 


Originally Posted by: Twister 


 


Basically the worst of both worlds. Not cold enough for snow but cold enough to feel crap. Truly awful weather at the moment temp wise. But at least it's not raining yet!


 


Bishop's Stortford 85m ASL.
Andy Woodcock
Tuesday, March 15, 2016 10:48:54 PM
Blimey what a boring outlook, 7-10 days of anticyclonic gloom coming up in the north west if the latest Beeb MRF is correct. As the high moves west more and more cloud will be drawn into its circulation off the Atlantic and not a sniff of a northerly.

Better than wind and rain I suppose but only just!

Glad I won't be in the UK to see it.

Andy
Andy Woodcock
Penrith
Cumbria

Altitude 535 feet

"Why are the British so worried about climate change? Any change to their climate can only be an improvement" John Daley 2001
LA2B MeridFlowEuro09
Wednesday, March 16, 2016 12:07:47 AM

It simply is the Dominant feature of UK weather, Azores High next week as well, the ECMWF, GFS and UKMO continue down this path of Anticyclonic High.  Still we'll see what the Models do to it, at the moment nothing in the way of clearer and colder weather in the next 7-10 days, no prediction seen for cold NW SE flow of clearer and colder weather, just cloudy with some odd sunny spells here and there!.


The dry spell that began about a week past still continues to control even Southern Europe seeing what we seeing...


Climate is warming up, Scotland and N Ireland and North England still often gets some Winter frost, ice and snow, November to March, but the SE and South UK including S Central England and Wales, together with the West and North through the year, they sometimes get more rain than London and S SE England, where some longer dry fine spells without much heavy rain is seen every year.

The North Atlantic Sea often gets some much Colder Wintry conditions from November to March Months, and Mild SW and South winds tend to be more frequent over the East and SE of North Atlantic Sea, as the Azores High tends to stay in charge. 

With this warmth and heat, the Central and South UK has become mostly free of snow and frost.

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