GFS 00z possibly showed us the ultimate warmest possible outcome for mid-Sep with a prolonged southerly delivering a dozen days of increasingly impressive warmth. This catapults a rough CET estimate of mine up to 15.6*C as of 22nd, to the sound of much gleeful chuckling from Col in my overactive imagination.

Even exactly average conditions thereafter would land the final CET around the 15*C mark.

The 06z is more restrained, but still suggests that the CET may be a good way through the 14s by 23rd. ECM shows good support for the precursor UK high setup D6-D10.

Starting to wonder if I'll regret punting for a total balance of cool and warm this month.

I’d be delighted if we end the month at 15c, but I won’t hold my breath!  Although I’m nowhere near the top of the table, so I hope it’s a bit higher for Col, who has far more at stake than me. 

---

Met Office Hadley           13.9c.     Anomaly       -0.6c  Provisional to 9th.

Metcheck                        13.53c    Anomaly       -0.19c

Netweather                     14.07c    Anomaly        0.38c

Peasedown st john           13.98c    Anomaly        -0.74c.           

---

Well, I imagine Col nearly keeled over when the 12z GFS of yesterday rolled out. The 00z of today wasn't much better either, but the 06z has upped the temperatures markedly for the 2nd half of next week onward.

This takes it toward the ECM 00z, which itself is warmer than the preceding 12z from that model, which was already much warmer than a downright chilly 00z before that.

 

So overall, we've been a big downward dip in the temp signals for late month - with a CET well down in the 13s being put on the table - followed by a considerable resurgence, with the GFS 06z giving me a rough estimate in the high 14s for the CET to 25th.

The ECM 00z looks to have less of a fresher interlude during the middle part of next week, so would likely yield an even higher CET estimate if I had the time for that.

I daresay Col has little reason to worry at this time (now just watch the 12z runs all align to the northerly outcome for mid-next week...!).

---

Well, I imagine Col nearly keeled over when the 12z GFS of yesterday rolled out. The 00z of today wasn't much better either, but the 06z has upped the temperatures markedly for the 2nd half of next week onward.

This takes it toward the ECM 00z, which itself is warmer than the preceding 12z from that model, which was already much warmer than a downright chilly 00z before that.

 

So overall, we've been a big downward dip in the temp signals for late month - with a CET well down in the 13s being put on the table - followed by a considerable resurgence, with the GFS 06z giving me a rough estimate in the high 14s for the CET to 25th.

The ECM 00z looks to have less of a fresher interlude during the middle part of next week, so would likely yield an even higher CET estimate if I had the time for that.

I daresay Col has little reason to worry at this time (now just watch the 12z runs all align to the northerly outcome for mid-next week...!).

Yes indeed, that did come as something of a shock! However the stunning previous charts were still for a week away and I've watched enough cold spells on the MOD thread unravel at that timeframe or shorter to know that nothing is remotely 'nailed on' at that distance. Conversely of course (as has happened to some degree) there is still time for the output to make it's way back again.

Thing is though due to the predictions of my closest rivals, I don't even have to be extremely close to preserve my lead. Even in the high 14s I will extend it.

 

---

11.8C (-0.5) to this morning here, it will go up for a while the next few days.

---

Met Office Hadley          13.9c.        Anomaly         -0.6c. Provisional to 10th.

Metcheck                       13.64c       Anomaly         -0.8c

Netweather                    14.07c       Anomaly         0.38c

Peasedown St John         14.19c       Anomaly         -0.53c.       

---

Met Office Hadley            14.1c.        Anomaly       -0.4c. Provisional to 11th.

Metcheck                         13.83c       Anomaly       0.11c

Netweather                      14.3c        Anomaly        0.61c.

Peasedown St john       14.25c      Anomaly        0.27c.     

---

Yes indeed, that did come as something of a shock! However the stunning previous charts were still for a week away and I've watched enough cold spells on the MOD thread unravel at that timeframe or shorter to know that nothing is remotely 'nailed on' at that distance. Conversely of course (as has happened to some degree) there is still time for the output to make it's way back again.

Thing is though due to the predictions of my closest rivals, I don't even have to be extremely close to preserve my lead. Even in the high 14s I will extend it.

Your wise wariness shows with the latest model trends... albeit with GFS and ECM finding cooler outcomes via very different paths; the former suddenly much more progressive and then flatter with the pattern, such that the really warm air barely gets a look-in before getting blasted aside, while the latter is opting for more of a UK-based high bringing the possibility of chilly nights leading to inversions and perhaps fog troubles.

I'm actually a little surprised to see this much wavering all of a sudden, despite how far away the big Euro ridge formation is in time. There's just so much working toward increasing the atmospheric angular momentum during the coming week or so. When AAM rises strongly, the subtropical high tends to get booted out of the Azores to take up residence across Western or Central Europe for at least a week. There also tends to be a broad trough digging well south in the North Atlantic, with a weaker jet stream than usual by the UK and Europe.

I suppose ECM's UK-based high is a reasonably realistic variation on the theme, but the mobile GFS solution really doesn't fit with the rising AAM, but might just about be feasible if more than one tropical cyclone in the Atlantic basin behaves in such a way as to 'turbocharge' the polar jet via a regional large increase in the temperature gradient. I don't think a single one would really produce enough of an impact to fully override the response to a big climb in AAM.

 

Hmm, why on Earth am I delving so far into this? 

---

Met Office Hadley         14.3c          Anomaly        -0.1c.  Provisional to 12th.

Metcheck                      14.02c        Anomaly        0.30c

Netweather                   14.55c        Anomaly        0.08c

Peasedown St John  14.64c       Anomaly      -0.08c.

---

Still not too shabby!  We’ve had two or three mild nights which I think have held up the daily mean temps.  A few warmer days to come now but I still think it’s all eyes on overnight minimum temps.  

---

Still not too shabby!  We’ve had two or three mild nights which I think have held up the daily mean temps.  A few warmer days to come now but I still think it’s all eyes on overnight minimum temps.  

I think for those of us in the '15 Club' for September it's still going pretty well. But you are right, it's all going to be down to the cooler nights. A lot of the forecasts I am seeing emphasise cool/chilly nights, even local ground frost and turning cooler overall at least for a time after Sunday so the CET may not rise quite as much as we might like. If I could make my prediction again I would downgrade it a little to around 14.9C but overall I'm still happy. Onwards and upwards!

---

 

I think for those of us in the '15 Club' for September it's still going pretty well. But you are right, it's all going to be down to the cooler nights. A lot of the forecasts I am seeing emphasise cool/chilly nights, even local ground frost and turning cooler overall at least for a time after Sunday so the CET may not rise quite as much as we might like. If I could make my prediction again I would downgrade it a little to around 14.9C but overall I'm still happy. Onwards and upwards!

Hmmm!  As suspected!  Single figures overnight, which is not good!  If that’s indicative of the three CET stations, we’d need a daytime max of mid twenties for the mean to benefit us ‘fifteeners’.  Some cloudy nights needed!

---

Met Office Hadley         14.2c        Anomaly     -0.1c Provisional to 13th.

Metcheck                      13.90c      Anomaly    0.18c

Netweather                   14.56c      Anomaly    0.87c

Peasedown St John    14.8c    Anomaly     0.8c.    

---

Now still 14.2°C to yesterday, 0.1C below the LTM

---

Met Office  Hadley as already posted       14.2c.    Anomaly      -0.1c. provisional to 14th.

Metcheck              14.03c      Anomaly      0.31c

Netweather           14.52       Anomaly      0.83c

Peasedown St John  14.46c   Anomaly      0.26c.         

---

Warmth is generally less prevalent in the modelling now compared to a few days ago.

The nights into each of Tue, Wed & Thu look to widely drop down into the 6-8*C range, but the days may climb widely into the 20s to compensate. It depends which model you look at; GFS is wrapping in considerably more cool air from the NE than ECM & UKMO, resulting in daytime max temps generally 1-3*C lower.

ECM continues to advertise a decent blast of warmth Fri-Sat followed by a 'gentle simmer' for Sun-Mon as the Atlantic lows struggle to make inroads. UKMO's going for a similar peak of warmth but shorter-lived with a very progressive Atlantic trough, while GFS is actually less progressive, but doesn't get as much warmth in to begin with.

So, not the clearest of pictures there...!

The following week shows signs of a more 'standard' westerly regime, temps perhaps doing alright overall, though this is assuming that GFS diving troughs down through the UK from the northwest is a consequence of its inability to capture rising-AAM periods beyond about a week's range (due to a systematic low-AAM bias).

 

Overall, I sense a mid-14s finish to the CET has started to become favoured, unless the final week of the month proves to be a warm one (no clear signals on that yet).

---

Yes SC, my gut feeling is for a mid 14 finish now, with the night time minima being the deciding factor.  I expect a small rise today following a mild night but I think ending at 15c is a big ask now, given the current output. 

---

12.0C (-0.4C) here at half way

---

Yes SC, my gut feeling is for a mid 14 finish now, with the night time minima being the deciding factor.  I expect a small rise today following a mild night but I think ending at 15c is a big ask now, given the current output. 

I feel that this one is starting to slip away now. There are simply not enough very warm days on offer to offset the chilly nights. Besides The Express is predicting a 2 week heatwave so that's the end of that!

---

Met Office Hadley         14.3c        Anomaly       0.1c. Provisional to 15th.

Metcheck                      14.6c        Anomaly       0.44c

Netweather                   14.6c        Anomaly       0.91c

Peasedown St John     14.54c      Anomaly      0.6c.

---