The Seasonal Forecast Thread

[BLAST FROM THE PAST]

According to your forecast, if the January cold spell does not come off, then this Winter really won't be up to much because that was the only real window of opportunity for deep cold?

Tell you what, window gone and there is unlikely to be any other 'very wintry' window. Growing strong signal for a mobile February too. if this one couldn't be taken then for me this winter is in real trouble. I was of the opinion that a large euro block would continue to migrate to Greenland come Feb with a potential strat warming, models suggested the block would be further north which excited me but they now show it sinking in FI and a disaster for cold. So I think the block will develop as planned but there has been less cold around and I have little hope of a mighty Feb developing, for me more of the same to come generally. I wouldn't bet against though end of winter/early spring being our 'winter'!!!!BFTP Edited January 12, 2014 by BLAST FROM THE PAST

[BLAST FROM THE PAST]

Just a quick update, its tried but this week is IMO our winter.  Signal for Feb looks to be as above with more Atlantic driven weather, I anticipate the Canadian Vortex to remain as it has been most of this winter.  I would also not be surprised to see a SW/NE axis develop as we go through Feb...so basically more mild than cold to come...so for me we continue to look West. I hope the block does develop and be influential just to dry us out, for it looks like as we head into Feb we're in for more bouts of heavy rain.  Funny old winter this....lots of incredible cold about but not in our quarter.  With the Jetstream behaving us it does there has to be somewhere really cold and somewhere really mild......looking back and using the 132yr solar cycle......the winter of 1881/2 was a mild one amongst a run of cold ones...maybe the writing was on the wall for me?

 

 

BFTP

Edited January 27, 2014 by BLAST FROM THE PAST

[Gray-Wolf]

I think our problems arise from the far side of the U.S.? The High Pressure over the north Pacific has just stayed and stayed. Run the Jet over this 'block' and then into the Rockies and you set up the peturbations that lead to repeated cold plunges for the U.S. and an energised jet over the Atlantic ( driven by the potential between hot/cold over the U.S./Atlantic).

 

When the H.P. loses it's impacts over there then the ripple down impacts here will reflect it? As it is? well it appears there for the duration. How long has that High been parked there and what 'ENSO' phase does it best fit with?

[Don]

Very close to giving up hope for Winter 2013/14 now that we are at the end of January with nothing particularly cold on the horizon.  However, as I said at the beginning of December, if this winter turns out to be a stinker then so be it.  I have to say RJS has done well so far but unfortunately the only part of his forecast that has gone wrong was the January cold spell!

[UV-RAY]

I think our problems arise from the far side of the U.S.? The High Pressure over the north Pacific has just stayed and stayed. Run the Jet over this 'block' and then into the Rockies and you set up the peturbations that lead to repeated cold plunges for the U.S. and an energised jet over the Atlantic ( driven by the potential between hot/cold over the U.S./Atlantic).

 

When the H.P. loses it's impacts over there then the ripple down impacts here will reflect it? As it is? well it appears there for the duration. How long has that High been parked there and what 'ENSO' phase does it best fit with?

A good question, I would say something similar to one of those  awful ( for cold and snow ) nineties, early noughties winters GW, possibly even mid 70S?

[shedhead]

Looking at the current NWP, my winter forecast that I declared dead early last week then reincarnated on Friday, now looks dead again! Very happy with how the first half panned out, but my late Jan slide into a cold, wintry Feb now looks bust unless there is some sort or dramatic turn round or a VVSSW...

[cheeky_monkey]

I think our problems arise from the far side of the U.S.? The High Pressure over the north Pacific has just stayed and stayed. Run the Jet over this 'block' and then into the Rockies and you set up the peturbations that lead to repeated cold plunges for the U.S. and an energised jet over the Atlantic ( driven by the potential between hot/cold over the U.S./Atlantic).

 

When the H.P. loses it's impacts over there then the ripple down impacts here will reflect it? As it is? well it appears there for the duration. How long has that High been parked there and what 'ENSO' phase does it best fit with?

Living where i live that huge pacific ridge has been pretty much parked there since the summer of 2011 to varying degrees so that's nearly 3 years now.

[summer blizzard]

I think our problems arise from the far side of the U.S.? The High Pressure over the north Pacific has just stayed and stayed. Run the Jet over this 'block' and then into the Rockies and you set up the peturbations that lead to repeated cold plunges for the U.S. and an energised jet over the Atlantic ( driven by the potential between hot/cold over the U.S./Atlantic).

 

When the H.P. loses it's impacts over there then the ripple down impacts here will reflect it? As it is? well it appears there for the duration. How long has that High been parked there and what 'ENSO' phase does it best fit with?

 

It's been around the last few winters and is more of a Nina response. I don't think it's causing our problems though, they are rather coming from a persistent +AO.

[cheeky_monkey]

It's been around the last few winters and is more of a Nina response. I don't think it's causing our problems though, they are rather coming from a persistent +AO.

Is it though?..it wasn't there during the winter 0f 2010-11which was a very La Nina winter which was very cold and snowy..the winter of 2011-12 was a similar La Nina winter set up but was wholly different than the year before even though all winter forecasts issued for Western Canada during the Autumn expected that winter to be even colder than the winter before...however it turn into the 2nd mildest winter on record and snow-less..the last two winters including this one have been fairly neutral in terms of Nina conditions..yet we have a similar pattern to the last 2 winters again..with that huge ridge not really going anywhere too much...with some spells of remarkable warmth that have appeared esp during the months of January and February..so there must be something else going on here?

[BornFromTheVoid]

I thought I'd give some thoughts on how my winter forecast is going.

 

First off, my December forecast.

 

A strong Atlantic ridge stretching into southern Greenland, coupled with low heights stretching from Scandinavia to the Iberian Peninsula, look to be the main features for December. An increase in northerly orientated winds could be expected with this set up, but, if the trough moves much further west, the is a chance of some milder southerly winds occurring, sourced from the western Mediterranean.

 

Precip is likely to be close to average, with a slightly higher chance of above rather than below average monthly totals.

Temperatures are more likely to be below average, with a CET estimate of close to 4C

 

Forecast Chart ..................... ............................  Reality

 

Thoughts: Not so good!

I did add the caveat that if the pattern shifted much westward, that we'd end up with more southerly winds. But it's so different I just cannot fall back on that. The upper pattern was by far the most wrong since I started this last May. I can't really say why it went so badly, this being the first winter I've attempted to forecast.

Anyway, no excuses, I'd rate that 1/10.

 

 

On to January, so far

Northern blocking, a west based -ve NAO and a large trough across central Europe are the main features for January. Northerly and northeasterly winds are likely to be more common during the month.

 

Rainfall is likely to be average or slightly above, with the driest weather to the south and west.

Temperatures are likely to be below average once again, with the coldest conditions further east. The CET estimate is 3.0C.

 

.... Forecast Chart ........................... ................. Reality

 

Thoughts: An improvement!

The general pattern appears to have been captured fairly well, with the high latitude blocking and deep trough nearby. Unfortunately, the trough ended up a little further west than anticipated, which very much changed the temperature profile I was expecting. Thus once again, demonstrating how difficult it is to get the temperature right for our small corner.

Overall, I'd say 6/10, the pattern being quite good, but losing many marks on temperature and a few on rainfall.

 

 

My hopes aren't high for February, but you never know. Going by the trends so far, I'd expect the chart below, but everything shifted northwest, which wouldn't be so great for cold and snow prospects.

[Interitus]

BFTV is that chart how February would look now based on the same techniques but with the benefit of current data or your original?

Edited January 28, 2014 by Interitus

[Suburban Streamer]

i'll go over my entire winter forecast in march but just wanted to post this feb chart. as much as i didnt want this to verify, it does look odds on, for at least the first half anyway

i still have my glass half full, and hold out a bit of hope for some snow in feb

 

 

Its been fun doing my first LRF this season, lots to learn in March. overall not too bad for a first attempt. Temps my biggest downfall. Anyway, thats for March

(full forecast is in my sig btw)

Edited January 28, 2014 by Suburban Streamer

[BornFromTheVoid]

BFTV is that chart how February would look now based on the same techniques but with the benefit of current data or your original?

 

It's the old forecast chart, I'll post one with the updated data this evening if I have the time.

[BornFromTheVoid]

February chart using the latest data

 

[Summer Sun]

February chart using the latest data

 

 

Got any charts for March BFTV?

 

Also how is precipitation looking on those charts?

[BornFromTheVoid]

Got any charts for March BFTV?

 

Also how is precipitation looking on those charts?

 

With the north and west shift seen in January and December, I'd guess that the low heights would be closer to us, so potential for some more unsettled weather, but I wouldn't have much confidence in that.

 

Using the same dates... here's March

 

 

That's not my forecast though!

[virtualsphere]

I thought I'd give some thoughts on how my winter forecast is going.

 

A fair assessment there and a good read BFTV - I've enjoyed reading your forecasts and hope you'll be posting more for spring and summer when the time comes.

 

Reading through some of the winter forecasts again and it does look like a good forecast from RJS once again (assuming current modelling verifies for Feb, which I'm hoping it won't).  I have to admit to being a little concerned when Roger posted his original winter forecast following his forecasts for summer 2013, particularly July, and previous winters.  

 

Credit also to chionomaniac's NW forecast especially for Jan & Feb - having seen the two options for Feb reposted in the strat thread earlier this week it does look like a very good assessment of the possible outcomes based on the current pattern - with the less popular one now unfortunately looking like coming out on top.

 

With a month to go, still too early of course to be certain of the outcome for the whole of Feb, and respect to anyone who attempts a LRF considering the work involved and the amount of data available to use.  The more detail that is included, the harder it must be to get the forecast to verify, particularly when a forecast includes the evolution of the synoptic patterns rather than just rain / snow.   Hope to see more forecasts posted here for the rest of the year!

[Peter H]

Have any Spring/Sumer forecasts been issued yet now that we're at the end of winter ?

 

Haven't seen any so far. 

[Don]

Have any Spring/Sumer forecasts been issued yet now that we're at the end of winter ?

 

Haven't seen any so far. 

 

I believe RJS's latest thoughts are going for an average March with some cold zonality, a cold April, warm May and June and then closer to average for the rest of Summer.  Obviously a long way off until Summer but he did call the general Winter pattern correctly as far back as late August.

[Roger J Smith]

In general the above is correct, but I am taking time to upgrade the model and won't be issuing a detailed spring forecast, look for my summer outlook some time in May. I am adding results of six new factors studied and this could change some of the details although the maximum variability from them is under ten per cent of the total. 

[BornFromTheVoid]

Here's the current March forecast based on based on the analogous years to this.

 

 

Temperatures are likely to be close to average, with rainfall also close to average

 

If the winter was anything to go by, a north west shift on the above GPH chart could be expected, which would put the trough over us and slightly higher pressure to our east, whilst maintaining some northern blocking.

[Zenarcher]

My March 2014 forecast http://forum.netweather.tv/blog/227/entry-4729-march-2014-forecast/

[BornFromTheVoid]

April 2014 composite chart

 

 

1983 was the most analogous year though.... (CET of 6.8C)

[Roger J Smith]

This will be a preliminary forecast from my research model for summer 2014. A final forecast will be issued around 15th May.

 

First of all, the output shows slightly above normal temperatures for the rest of climatological spring, and my estimate for May CET is 12.0 C. Expect near normal rainfalls north and east to above normal south and west.

 

For the summer months, the output shows rather bland, near normal conditions for much of June and July, with a warmer than average August. My preliminary estimates of CET would be 13.8 (June), 15.8 (July) and 16.8 (Aug). No large rainfall anomalies are indicated.

 

Will update this brief first look in May.

[Supercell 89]

Just seen this thread after posting my early summer thoughts and clogging up the summer 2014 thread but i thought they be more suited to this thread instead. But I've never really done this before but will give it a go see how it pans out  

 

In regards to this summer, I've been doing a lot of background reading into signals such as the QBO, PDO and keeping an eye on the ENSO conditions as well and I have a strong hunch that this summer will be warmer and drier than average if and only if this supposed El Nino is able to get in gear in time. So I decided to give it a go and put together an amateur outlook to summer 2014.

 

Looking into just the QBO & PDO.  The QBO it looks to be turning into its negative phase most likely around June possibly July which isn't normally favourable for warm dry conditions during summer. The last time we saw a switch from negative to positive during summer was 2011 and 2009 before that, in which both also featured negative PDO phases. The negative PDO also enhances a cool wet pattern for the UK with a southerly tracking jet.  Now 2013 saw a -PDO pattern although it was weaker than in previous summers although it did strengthen towards August but we also saw a pretty strong +QBO event which peaked during July and August. A quiet MJO and low SST's around the UK both I think also contributed to us having a very warm July in particular, with the strengthening negative PDO and a more active MJO allowing for August to be more mobile and cooler. (Of course I'm not expert). 

 

The PDO has been positive the last few months which by no means guarantees a nice summer, however if this El Nino event is able to take off then it could encourage a continued positive, perhaps a strongly positive PDO during the summer this year, which will hopefully mean the jet stream will move northwards as it should do during the summer instead of tracking southwards.

 

When looking at other years to match the introduction of a Negative QBO during the summer months to this year I found the following years :-

 

1967

1976

1981

1983

1986

1988

1991

2009

 

A very interesting mix especially '76 and '83. 

 

From that list we have;

 

2 Very Warm Summers (1976, 1983)

1 Warm Summer (1991)

1 Average Summer (1967)

4 Cool Summers (1981,1986,1988 & 2009)

 

The composite I got from all of those years was interestingly quite good, although the high pressure anomaly is quite weak. 

 

http://www.esrl.noaa...mit=Create Plot

 

By taking out the La Nina year (1988 as its very unlikely to happen) and those with -PDO patterns throughout the summer (1967,1991 and 2009) we get the following composite;

 

http://www.esrl.noaa...mit=Create Plot

 

This time we can see a much stronger high pressure anomaly right over the UK and North-Western Europe. Just for interest if we take the -PDO years and the La Nina summer we get the following composite;

 

http://www.esrl.noaa...mit=Create Plot

 

So my thoughts are if we can keep a positive PDO throughout the summer with an El Nino and the QBO transition is slow or the negative QBO weak then we could get a pleasant summer with more lengthy warm dry spells of weather .