Supercell 89

Looks as though the PDO is finally starting to show signs of beginning to turn negative at last. Cold anomalies beginning to develop off the west coast of the states and across the mid-pacific. Very similar to the post 97/98 El Nino event. If this continues then this could give a boost for La Nina to strengthen during the Autumn.

I'm a little puzzled as to why the meto and beeb are predicting only snow for high ground for the majority of the week. Unless I'm missing something the models to me suggest snow at lower levels at times throughout most the week. Wednesday and Friday morning being the only periods we are not under the -5C line. It is a tricky set up but I'm just a little puzzled. Friday morning could be interesting however if that low tracks further south or the cold air digs in quicker than currently projected.

Beginning to wonder with region 3.4 being +3.0C and region 1+2 being 1.5C whether this may cause the response from the El Nino to be more modoki like? As in previous years the temperature difference between those regions must have been the same? The last week the Aleutian Low seems to have drifted further west with High Pressure ridging into Alaska.

Certainly going to be an interesting few weeks and winter ahead. Just read a paper from Cohen on wave 1 and wave 2 activity as part of my dissertation topic and seeing what the general patterns precede each type of polar vortex disruption which was very interesting. I did think last week the current patterns look very similar to what happens prior to a splitting event and continue to look even more in line with what they normally see (although I'm still learning so I could be off the mark). However one thing i have found is that El Nino year feature predominately wave 1 activity whilst La Nina favour Wave 2 which is interesting. In case anybody is interested in reading the paper http://web.mit.edu/jlcohen/www/papers/CohenandJones_JC12.pdf Link to mean zonal wind anomalies and wave 1/2 annual activity http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/

Just had a nice blustery shower go through Reading. The first interesting weather event I've seen since we had the thundersnow in February

The QBO was +ve and transitioned to -ve during the second half of the winter. The PDO was +ve all the way through which is pretty normal for El Nino, particularly strong ones.

It will be interesting to see how the warm STT's off the west coast of North America interact with the strengthened ST jet during the winter months and how that has an influence further down the line for Europe. From what i've looked into +QBO winters combined with El Nino are generally mostly mild for western Europe but It depends on how other signals such as the stratosphere, solar output ect all interlink.

I think the PDO its likely to stay +ve during the summer however it may wane slightly in comparison with recent months before strengthening again providing the El Nino follows suit. Will be interesting to see how summer pans out, with a -qbo and a strong positive pdo combination I personally think we'll see a mid-atlantic trough and euro high set up for most the summer with the trough drifting west every so often but thats just my humble opinion. I don't favour winter being cold despite some of the suggestions floating around today. The last +ve qbo winter with an el nino was 2006/07.

I think I'll have to go for 1) Broken Bow - Would loved to have seen this one!! 2) Limon HP - Love the turquoise streak through it 3) Campo - A bit of bias towards this one have a very similar photo to Dribbley of that one

I find it interesting that this El Nino struggled to get going and is pretty much vanishing before really getting anywhere, I wonder if its the atmosphere not really playing ball and wanting to go back into a more La Nina state or after that massive kelvin wave last spring there was nothing for a few months and the momentum was lost until the autumn, or a combination of both. The the strength of the +ve PDO I think can be explained mostly by the kelvin waves. Please excuse my rather amateur annotations. Looking back at last year the PDO was only weakly negative prior to January which is when we saw that huge kelvin wave appear, (think it appeared just before January). Following that the PDO gradually became quite strongly positive by May. In the early summer when the kelvin wave finished it was followed by a brief lull, which saw the PDO values drop during June, July & August before a further round of kelvin waves appeared during the late summer onwards and another sharp increase in the PDO was seen and we had the weak El Nino forming. The large values of the PDO to me suggest that we should be seeing a strong ENSO event but whatever seems to be watering down the effects of the El Nino isn't necessarily having the same impact on the PDO, possibly? I'm not an expert and I don't know the full answers but thats just my humble thoughts and thought i'd put my two pence worth in. But if this is true then I doubt we are seeing a longterm trend emerge and it could just be a blip in an otherwise prolonged -ve state and once these kelvin waves weaken and stop we may well see the PDO swing back to a -ve state, knockers post suggests the atmosphere is starting to tip that way again, bit early to jump to conclusions though.

Well I think i'm the only one who's not downbeat by tonights output. Its not mild, its not wet Instead its dry and cool/cold at least for another week, ok its not crisp sunshine but who knows it might be and i'd rather have this any day over boring mild crap southwesterlies. I don't think this High pressure will be going anywhere fast, have been wondering whether its persistence may have a feedback on the stratosphere in the long run, plenty to be optimistic about yet

Still snowing lightly but got a brief heavier burst. Not sure whats going on as its not on radar :S

Light snow still but has gone up a notch coming down thickly now and getting a dusting on the ground

Light snow here which is trying to settle and has done on the usual favoured spots although we did have a brief heavier burst that started to stick everywhere. Looks like Oxford has nailed it pretty well again, think we may have this on and off for the next hour may end up with a nice dusting Amazing how this has turned out, wasn't expecting anything today at all.

Please tell me I've not missed a thundersnow event back at home! Hoping for something here at uni later tonight