Still a lot of guesswork for the starting observed-to-date figures, but the GFS 06z was certainly extraordinary in bringing an extended run of day temps widely hitting the mid-high teens to follow the several days getting into the 20s this coming Sat-Mon.
The CET anomaly first peaks on 19th at somewhere between +2.1 and +2.5*C. The actual is between 13.5 and 14.0*C at this point.
Then, after the briefest of slides, it edges relentlessly further upward all the way out to 26th, at which point the anomaly is between +2.5 and +3.0*C with the actual value very similar to that on 19th; the mean holds fairly steady but the long-term average drops down, hence the anomaly increasing.
So I'd guess that this run would lead to a final month-mean CET near to 13.5*C. How would that stand in the record books I wonder?
The 12z GFS produces very similar CET estimates out to 20th but then a more mobile regime introduces some wedges of cooler air at times, with the Euro High having a go at fighting back for a time 22nd-24th but then being swept aside by Atlantic troughs, with the main ridge shifting to the mid-Atlantic and then building up to Greenland to set up a genuine cold spell for the turn of the month (when extrapolating forward from the run's end; some assumptions made there regarding disturbances in the flow remaining unobstructive).
Even though the CET for 21st-27th is just under 10*C and so a lot cooler than before that time, this is only able to drag the CET down to between 12.5 and 13.0*C as of 27th, and with the LTA dropping away too, the anomaly is still pretty mighty at between +1.5 and +2.0*C. Even with a particularly cold last four days, the CET would struggle to fall much below 12.0*C, with the anomaly likely staying above +1.0*C.
SO... it would seem likely that this coming warm spell plus the suggestions of further very mild or quite warm conditions at least for part of the Tue-Sun period next week are making a notably mild October CET very likely indeed. Preventing that will take a cold spell - with lows near freezing and highs struggling to make double digits - setting in for at least a week prior to month's end.
If you have any problems or queries relating to TWO you can Email
[email protected] 🙂
https://twitter.com/peacockreports 2021's Homeland Extremes:
T-Max: 30.4°C 21st Jul | T-Min: -6.8°C New Years Day! | Wettest Day: 34.1mm 2nd Oct | Ice Days: 2 (27th Jan & 8th Feb)
Keep Calm and Forecast On