It's having to use Zeller's Congruence to calculate the day and there's an issue with the script path. The chart is correct. 

We had some decent fog back in November..

I'm not surprised there's trouble with the script. Any algorithm based on 14 months in the year is asking for trouble.

https://www.reddit.com/r/learnpython/comments/7mpmqn/zellers_congruence_for_the_life_of_me_i_cant/ 

I'm thinking that when I were a lad, you wouldn't have seen the street lights further than 4, maybe 5 away in  a 'decent' fog - which also lasted for at least a couple of days. But maybe memory is exaggerating ...

I actually wrote the script myself as a plugin to GrADS which is the application most charts on TWO are generated with. Surprisingly, it works well when correctly used. 😂😂

Yes. -  I remember it well, when my parents were driving back from my Uncle and Aunts house, seeing the powdery snow blowing about over the road like dust, well sub zero and an already frozen ground, And next morning, i awoke to the sound of tractors from the nearby farms digging out cars stuck in the dip that contained our house, that had seemingly filled up with snow - which lay 50 cm deep in the road channel, and everything Squeaked And clumped down in dollops as deep snow shifted And slid on roofs and  off trees. marvellous - a snow addict was created that day!!

With PHP you'd just use something like this to add the date to the image - I'd have thought asp.net would have similar functionality built in?

header('Content-type: image/jpeg');

$jpg_image = imagecreatefromjpeg('webcamnew.jpg');

$white = imagecolorallocate($jpg_image, 255, 255, 255);

$font="c:/windows/fonts/segoeui.ttf";

$text = "UKWCT - ". date ("l, F jS", strtotime('+0 hours', filemtime("webcamnew.jpg")));

imagettftext($jpg_image, 32, 0, 20, 1060, $white, $font, $text);

imagejpeg($jpg_image);

imagedestroy($jpg_image);

(The above is an edited version of the code to date- and time-stamp the webcam image on the UKWCT website).

Yes it does, but the charts are generated in GrADS and asp.net is only used to display them. The inbuilt day function in GrADS stopped working several years ago, hence the need for a workaround. 

That's what I was getting at - rather than have GrADS stamp the image, do it afterwards (per image) in asp.net? It takes just a few milliseconds to do it in PHP - if you go here you'll find it loads instantly:

https://ukwct.org.uk/webcam/webcam.php?1765649591406 

I think most people will be glad of a much drier spell, even if it is a mid-latitude block and even if it isn't especially cold. The ground here is sodden and really can't take a great deal more rain now without there being a real risk of flooding in places, so the more settled spell now being indicated by the models as we approach Christmas will be most welcome. 

Well only 16 days away haha! The Met office and BEEB etc long range have gone for higher pressure so I doubt that low will be maintained in the forth coming runs! 

I don't know about MJO and DOTs in a circle - can you elaborate more? This doesn't effect our weather I don't think!?

Beyond that it's white, so near-normal.

It'll have been a long time since we last saw deeper blues over the UK on these charts in December (of course, they were mostly unavailable to us mere mortals until the last few years, but even so!)

https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202512130000&projection=opencharts_europe&valid_time=202601050000 

The pressure anomaly charts are strongly suggestive of high pressure close by, perhaps over the UK:

https://charts.ecmwf.int/products/extended-anomaly-mslp?base_time=202512130000&projection=opencharts_europe&valid_time=202512290000 

So all in all - a marked change on the way. If nothing else, it'll be nice to have more seasonal weather over the festive week for once.

"Large amplitudes (outside of the circle) signify strong cycles of the MJO, while weak activity appears as rather random motion near the origin."

Yes that nasty low has gone, infact gfs finally going away from the zonal influence. Their cloud cover forcast looks positive for clear skies too although freezing fog lifting will be a factor.Yes a more old school cold snap to enjoy with frozen lakes, not snowy at present but winters like the past month are not welcome.

In any other sense, looking at rainfall charts for the Indian Ocean and inferring the weather here as a result would be laughed out of court.

I really don't rate the MJO whatsoever, albeit it's fun watching folks on other sites get all excited about it, only to vanish when (as per usual) nothing much happens when it goes into phase 7-8-1.

(Yes, it will have some effect, but equally well the weather here will influence the MJO too in due course. It's just one very small, insignificant part of what drives our weather. If there were a magic formula we'd all have known about it long ago!)

As it stands it’s likely to be a ‘seasonal’ Yule with colder and more settled conditions than of late, with the hint at this stage of something a little more enticing post Christmas. 

GFS Op 0z: the secondary low deepens and runs NE-wards to N Scotland. The next LP is weaker 995mb and runs SE-wards from Galway Sun 21st to Spain Thu 25th which, with pressure rising 1040mb S Norway brings in quiet (and cooler?) SE-lies for Christmas Day. A ridge of HP from the Azores combines with the Norwegian HP and by Sat 27th a cell of HP 1040mb is centred over N England persisting to at least Tue 30th. Frost and maybe fog for Christmas?

ECM: puts more emphasis on the approach of HP from the SW, but arrives at about the same place for Christmas Day with 1030mb Scotland, though the lack of HP over Norway allows some (slightly) colder from the NE to affect S England. The HP cell is less persistent and soon drifts off to the Norwegian Sea leaving quiet but colder weather post-Christmas.

AIFS London maxima now about 10C dropping to around 5C over Christmas, some rain w/b Tue 16th , drier later. Edinburgh maxima about 8C in the first week, 5C in the second but a few colder days, rain until Sun 21st then dry 

GEFS: postage stamps at T+180 (Sun 21st) mostly variations on the theme of cold LP near Greenland and slack HP over Britain though a couple (P17. P27) place a shallow LP over Britain in the middle of higher pressure. Line graphs, for the south, mild to 21st then mean dropping to a degree or two below norm through Christmas (a fair spread of ens members, op and control amongst the mildest), rain likely Fri 19th (also 16th in SW), small amounts in some runs on other dates. For the north, mild now and around 19th, mean temp thereafter fairly close to norm. small amounts of rain for most of the area slowly drying up, but more across  N England in peaks now, 17th and 19th

Yes - but the trend is for a blocked pattern now - stage 1, and then stage 2 - improvement as it wobbles about - there are many promising pert’s - and I’d take P1, 5 and 20 any day, but there are others too with much promise. Great reading of the posts surrounding this build-up - its like an advent calendar(LOL), every day, there’s a new window on the model evolution and comments on it. And you get 4 doors to open a day with the GFS.

The raw GFS charts show frost in pretty short supply right out to the end of the run, sadly, despite high pressure in charge. Generally high single-digit maxes and low single-digit minima.

👍I've generally found it easiest to use the tdef in the .ctl file directly in GrADS script. It shows something like this:

tdef 1 linear 12Z25dec2025

I then build the date stamp from this part 12Z25dec2025. 

Rather not to have a HP here if going to be gloom and sunless, i seeing more sunshine during mobile pattern so hope this will happen to the end of the month if no prospect of deep cold and snow,  It going to get milder over Lapland with temperatures at less cold levels over 1 to 2c instead of -15t to -20C zone.