Jack Wales

With a negative AO progged for the first half of the month, I expect a couple of N'ly blasts to peg back the CET value. Although the second half of the month should be milder with warmer daytime temps, I expect high pressure to be a strong feature so with clear skies and lower minimas I predict the CET to come in just above average at 8.5C

7.8 for me please.

5th April - Hawarden.

There is a fairly wide scatter regarding the enso status into summer with the favoured outcome being a neutral/weak La Nina scenario. This is a good read from the noaa/cpc... La Nina Diagnostic Discussion

Yes it does seem to be the case that we are in a record breaking cycle of mild winters, I wore shorts today for the first time this year and did not feel cold at all. Also this is the first winter in living memory where I have not seen a single snow flake (which is unusal in this part of Wales). Yes you are correct that with the moderate La nina, we should have expected the ENSO to have an overriding effect on our weather but not to the extent we have observed. One may have expected the strong ely QBO and favourable SST's to have resulted in cold incursions but instead our main cold spell being the result of an inversion.

Plenty of cold zonality forecast for Scotland on the 18z tonight, should be a good year not just for coverage but depth also. It will be interesting to see if more snow patches survive the summer too.

Another factor that would indicate a pattern change towards the end of the month into February is the six week anomalously cold NH Stratosphere apparently coming to an end... NH Stratosphere anom Up until very recently there were only small variances between ensemble members, even into FI but look at the 12/1/08 00z 850hpa for Cardiff... GFS Ensembles There is now considerable disparity between members undoubtedly due to the changes referred to by BF over the US and the track of the subsequent LP off the eastern seaboard.

Yes I believe we have forgotten what proper cold realy is, we had tasters in 1995/96 and 2005/06 but the very cold spells were relatively short lived and followed by mild. It would be interesting to see how the country coped with a zero CET month.

Yes Feb 91 is easily the coldest month of the last 20 years but with a CET of 1.5 it doesn't come close to the winters I remember as a kid i.e December 81, Feb 86, Jan 87. Whilst you a right to point out Feb 91, what's interesting is that there have only been three months since with a CET of below 3C which all occured in the 90's. All monthly CET's in the 00's have been above 3C.

I agree you can't blame one failed high, I was just using that as an example as to why we have not seen any prolonged significant cold since 1987. That's an interesting point regarding the winters of the 1920's, they were remarkably mild on avereage however still not as mild as the 1990's or 2000's as my winter CET calculations (Dec, Jan Feb) are as follows: 1920's 4.64C 1990's 4.78C 2000's 5.07C (does not include 2007/08)

I guess we'll have to agree to disagree. a 1060mb high genereally speaking would have greater 'reach' than 1040mb. Secondly I believe that the location of the HP cell is slightly displaced to the east due to the strong N'ly PFJ as teleconnections support a scandi high. Similar synoptics from the 60's and 80's in particular often resulted in the PFJ tracking south underneath the high allowing a 'proper' e'ly flow over the uk. This also encouraged heights over greenland and the 'holy grail screnario' which we never see now.

Hi, if you look at the winter CET (Dec, Jan, Feb average) for the last 20 years (1988/89 - Present) I think you would be hard pressed to find a run of 20 consecutive years in history with a higher average (one for Mr Data perhaps!!!). I agree that we will always have variability and of course there were mild winters and zonal synoptics even during the mini ice age pre 1850. What I'm saying is that the synoptics which delivered very cold winters such as 1947/1963 seem more and more unlikely nowadays due to the northlerly migration of the PFJ. Regards.

I know what you mean but the term does sum up our weather (particularly winter) over the last 20 years quite well. It basically means that no matter what the teleconnections or drivers are, our winter synoptics are nearly always mild/zonal. For example the 1060+mb high currently over Finalnd/W Russia would not have been brushed aside so easily by the jet a couple of decades ago, in fact a large HP cell of this nature tended to stick around for up to a month with an e'ly flow maintained over the uk.

GP, I've only just skimmed through you're forecast but what a magnificent piece of work. Thanks for the days/weeks you've obviously put into this as your technical knowledge and understanding are inspirational. This is definitely one to be printed off and mulled over at bedtime with a glass of scotch! Cheers John.

Winter weather forecast 2007/08 Good evening all, firstly can I apologise for not uploading this yesterday as anticipated but circumstances prevented me. Before I go any further I would like to state that although I’ve been interested in meteorology for 20 years, this is only the fourth time I’ve attempted a long range forecast and the first time I’ve published one! That’s not to say you cannot rip it apart if you so wish, in fact feel free to do so as I’d welcome all feedback. I merely wish to manage your expectations as this forecast will not contain the same level of expertise as forecasts by Glacier Point, Kold Weather, John Holmes to name but a few. Finally I would say that I’ve not viewed anybody else’s winter forecast yet (apart from the met office) so here it is guys and girls… ENSO: Forgive me for stating the obvious here but I’m going to start off by analysing the current ENSO signal, we are currently in a negative (La Nina) phase and this is how I categorise the MEI numerical values… >-0.75C Neutral -0.75C to –1.5C Slight -1.5C to –2.0C Moderate < -2.0C Strong Sept/Oct Reading: -1.117 (Slight) MEI Oct/Nov Reading: -1.5 (Estimate) Current Reading: -1.7 (Estimate) SST Also the ENSO region 3.4 (though to be the most influential), is currently recording an anomaly of approx –1.9C which is moderate (borderline strong). ENSO 3.4 The is some debate surrounding possible strengthening of La Nina but the general consensus is that it has peaked or will do so very shortly… ENSO Forecast I therefore predict that La Nina will peak at –1.7C and remain in the moderate category. This does have a strong correlation on our weather, in fact an ENSO signal with this strength often overrides other tele-connections with the pattern resulting in zonal conditions for western Europe. Having said that we are unlikely to see the very mild conditions experienced in winter 2006/07. The last time we experienced a La Nina of this strength was in 1988/89 (CET D7.5, J6.1, F5.9) or with a combined e’ly QBO 1976/77 (CET D2.0, J2.8, F5.2). In a nutshell from this signal alone I would expect to see a strong Atlantic jet interspersed with brief height rises over the northern mid Atlantic (classic toppler scenario). QBO (Quasi-Biennial Oscillation). Calculated at PSD (from the zonal average of the 30mb zonal wind at the equator. We are currently in a negative QBO phase, strongly negative figures have been recorded QBO There is a correlation between a negative QBO and a larger emphasis on blocked weather conditions, although the ENSO signal could be expected to override this the sheer extent of the anomaly is worth further consideration which I have factored into my forecast. Although the QBO has probably already peaked and should decline sharply to neutral values by the end of winter. The lag effect should ensure the effect of negative QBO are in force throughout the winter months. It has also been observed that an e'ly qbo can assist in locking-in synoptics i.e. so that given conditions can prevail for longer periods. AO… The AO ensembles indicate a switch to AO- conditions shortly, with the trend being towards AO negative conditions. Considering the tentative link between the QBO and he AO I'm certain we will not see the extreme positive figures of last winter and predict a weakly negative AO for DJF. If you look at our cold winters of the past you will note that a negative AO regularly prevailed (Jan 1963: -3.3). AO See ensembles… Ensembles Hints at a change in FI for mid December on the 1/12/07 12Z but I suspect GFS are a bit ahead of themselves here although I expect to see this sort of development from Christmas onwards. However the 1/12/07 00z GFS 850 HPA Temp ensembles show no particular trend with equal members option for mild/cold. Stratospheric Observation Stratosphere There is a correlation between a warm stratosphere with colder conditions at the surface although a 4 - 6 week lag is generally required for this to be observed. Therefore we need to look at the stratosphere from mid October to the end of November. You will see that at the end of October thru most of November slight cooling of the stratosphere notably between 1 - 30hpa. This possibly contributes to the recent change to a more zonal pattern (also note the very recent spot of yellow at the surface). The cool anomaly remains until the last week of November so this would favour a more zonal pattern at the surface for December. The pattern does change during the final week of November where finally some warming is recorded. Although this anomaly is relatively slight it does represent a pattern change which could favour blocked conditions towards the end of December. The stratosphere currently bears a similarity to 2005: 2005 NAO (North Atlantic Oscillation) The Met Ooffice predict a neutral NAO and although they do not stipulate exactly how they arrive at this, Atlantic SST's in spring time (May) are thought to be the main driver. At this time La Nina had not shown her hand so I predict a weakly positive NAO to the tune of +1.0 December: NAO PNA (Pacific North American Pattern) Owing to the Moderate La Nina this is likely to be predominantly negative this winter which teleconnects with zonal conditions for W Europe. Having said that the ensembles are currently progging the PNA to turn positive during mid December which could help enhance –AO and NAO for late December early January. PNA I predict the overall PNA for DJF to be in the region of -1.3. SST SST signals in the Atlantic are mixed and favour neither NAO+ or - conditions, the tripole we saw earlier this year has all but disappeared there are few 'cold over warm' anomalies to invigorate the jet further. SST Ice extent/Albedo effect There is a correlation (albeit loose) to cooler winters and ice/snow coverage. During summer 2007 we saw record breaking extent of minimum ice cover in the NH. Although a significant recovery ensued during autumn, ice levels remain low at approx 1m sq km below average. Summary: Needless to say La Nina is the spoiler for cold weather lovers this winter. My forecast would have been quite different had ENSO neutral conditions prevailed as expected during the summer. Having said that I do not expect it to be continuously mild as it was last winter. As previously mentioned I expect N’ly incursions only to be toppled by the jet. However I do expect the jet to take a slightly lower track due to the negative AO although not significantly so, instead the jet will be squeezed more tightly around 50 – 55 deg N resulting in some stormy conditions. I don’t expect the mild to get all it’s own way and although this winter look likely to be above average in terms of temperature I wold not rule out at least one significant cold spell (to last around 7 days). Although I’m not going to chance my arm and predict when, I expect January to be the month most suitable to blocked conditions and have reflected this in my CET predictions below. I do believe that winter starts to show it's hand in November, not necessarily in terms of temperature and precipitation but synoptically. Whilst there has been a trend towards more mobile and zonal weather we have seen on two occasions that the Greenland high has tried to form and ridge down to the mid Atlantic high. Although the jet has blasted through on both occasions I believe this synoptic will come off at least once point during the winter. Finally I expect northern Britain, to experience more frequent spells of polar maritime air which should mean a better year for the Scottish ski resorts. Here are my predictions for this winter Precipitation December Above average January Slightly below average February Average Overall Average Temperature (CET) December 6.0 January 3.5 February 5.5 Overall Above Average Thanks for taking the time to read my forecast. Adrian

I remember a cold snap in September 1992 (or maybe 1993) which I'm told produced snows showers in Merthyr and a covering on the Brecon Beacons.

Buxton is another one that crops up quite regularly, Yeovilton can be good for low maxima and despite its location in SW Wales, Pembrey Sands wins the lowest minima about half a dozen times a year, probably due to its sandy soil.

Carinth, I was going to post about the svalbard snowfall but you beat me to it! Here are some more pics Svalbard Webcams

Slightly better then June/July with more dry but not necessarily warm conditions. On the basis I expect us to be under a predominantly cool W/NW airflow I'll go for 16.6C.

Interesting but I'm not sure if I totally agree, I remember similar assumptions being made after the whopping Greenland high last August. For the medium term I agree that the signs are we could record some average/below average months especially when you look at the set up for winter as there is a favourable set up for those who prefer less mild conditions (I daren't say cold or that will jinx it!). If you consider the E'ly QBO, Probable ENSO neutral/weak negative, SST's and the predicted neutral/weakly negative NAO the potential is certainly there. I hope my postings have not been deemed to be hostile as I'm glad you raised the subject, your points have been thought provoking. However if I disagree with something I believe I'm entitled to politely say so, this does not mean I discredit other peoples views and it certainly does not mean I'm correct but I believe polite debate is healthy and good for the forum. No offence taken I hope.

Sorry but I must disagree again, 'Summer' and 'Winter' synoptics are incomparable. In winter there is a high probability the Jet would blast through any blocking to our north as it does almost every year, the classic toppler scenario. Plus we'd need the PV and a number of other factors to play ball.

Elderly or senile! Joking aside combined CET values for June July so far are not dissimilar to other years in the last decade i.e. 1998, 2000, 2002 and 2004. To suggest that there has been some kind of climatic flip as a result of a short period of average temperatures is in my opinion totally unrealistic. It's simply the result (as predicted by many on here) of the climatic effects of the transition from ENSO + to ENSO - conditions. I don't think anyone could draw any conclusions based on such a short timeframe anyway, unless we recorded a summer as in 1888 (June 13.2, July 13.7, August 14.1), then maybe I would sit up and take notice.

Agreed but I'd still like to have a nice summer first but the way it's going it could even turn out to be a summer horror show like in the late 80's! As for winter I'm sure something will conspire against cold as always but with an easterly QBO, weak La Nina (probably) and encouraging SSTA's I'm sure we won't see the raging mild zonality of 2006/07.

Doesn't bode that well for the rest of the summer though!!

My early thoughts are for a warm/dry start to summer with a return to a normal type autumn, I certainly don't expect an indian summer this year. June CET +1.0 to +2.0C Precip Below Average July 0.0C to +1.0C Precip Slightly Below Average August -0.5C to +0.5C Precip Above Average