Snowly does it

rounded up to 0.8 to the 20th then on Hadley, 7 per day now required to get to 3 Today will be below average and then Friday looks like being the last day anywhere close to the requirement for 3 or even 2.5 before the tail end of the month. 2.5 looks very much the upper marker for me now with 2.0 or thereabouts still favourite (especially after adjustments) Manley now requires over 5 per day just to reach 2.0 2.0 is the new 3.0 it seems and how ironic if we get stuk on 2.0 at the end of the month like last years 3.0 for January.

Height rises over Greenland, a tiny area of LP sinks the Siberian block into Europe and the ensuing monster system of HP manages to avoid any link up to Greenland whilst LP systems bomb and ride the tiny gap to give us SWrly gales with a prone set-up. Messy, messy stuff from T120 onwards - low res then sees a system go 87 on us over the top. Too much going on for my liking. HP nearby for the UK, could mean cold shots or could mean SWrlies, but far less complicated than the 12z version of events.

0.2 (0.15 rounded up) to the 17th Last night a fairly cool 1.7 2.0 is about the mark I think (after adjustments)

Interesting pattern on the 12z - the PV does not look intense over GL and a lot of cool to cold air about and ridging HPs by as early as T126 - plenty of options for cold here, however also the chance of us getting caught on the wrong side of the tracks.

A few more mileposts to look for this month To be the biggest negative anomoly against the 71-00 mean since it came into being --- 2.1 or lower The biggest winter negative anomoly against the 61-90 mean in 91-2000 was -2.3 in Dec 95 and Feb 91 ---- to beat against the 71-00 ---- 1.8 or lower To beat against the 61-90 average - 1.4 or lower Biggest -ve anomoly versus 61-90 average overall was Oct 92 at -2.8 to the mean ----- 1.3 or better for 71-00, 0.9 or better versus 61-90

Last sub-zero first half of a month was of course Feb 91 Some targets and what is required to beat them Coldest Jan/month this century needs 2.9 --- 6.2 per day to achieve Coldest Jan since 1987 needs 2.4 --- 5.0 per day to achieve Coldest winter month since Feb 1991 needs 2.2 --- 4.9 per day to achieve Coldest winter month since Jan 1987 needs 0.7 --- 1.7 per day to achieve Coldest Dec-Jan combos since 62-63 81-82 2.9 degrees (need Jan to come in at -0.2, so -0.2 per day from here) 78-79 3.0 degrees (needs Jan to come in at -0.1 so 0.0 per day from here) 76-77 4.8 degrees (needs Jan to come in at 1.7 so 3.7 per day from here) If we get another cold snap, we could have the third coldest Dec-Jan combo in the last 40 years and the coldest month for 19 or possibly 23 years

Hadley at -0.2 (-0.17) to the 16th - so a sub-zero half month bagged, will take a look at the last time that happened for the first half of a month... Last night was 2.3 so somewhere around 5 today I guess and we will be into positive territory. 6.25 per day required to get above 3 4.2 per day to get above 2 Will post some waymarkers to look out for shortly....

One or both of these reaiming criteria may well fall once the adjusted figures are released at month end - certainly Manley has one of those very cold days around or just colder than -5.0, and 4 out of 5 days were below -2.0, with the middle day being -1.7 and therefore well witin scope of being adjusted to meet criteria.

Dec 95 2.3 Feb 96 2.5 Dec 96 2.9 Jan 97 2.5 Those are the only 4 since Feb 91

Manley now at -1.9 to the 12th - with Hadley likely to update to -1.0 or thereabouts today, there is a large discrepancy - so a downward correction cannot be ruled out at month end again!

Similar output to earlier - 1060 Siberian HP cell a little too far East and the Atlantic held at bay with us in the middle - one mild day and then some rather average looking output, milder than usual in Ireland and Scotland who are more at risk of SWerly winds riding up the HP cell, but still it is eyes NE to see what transpires as it is clear the Atlantic isn't coming through the Scandi block - its all a question of how far the ant can nudge it.

wet snow shower here, temp at 2.3. Still have full cover generally but little patches appearing where roofs and trees are dripping and such like

Hadley at -1.2 (-1.24) to the 11th, yesterday a balmy 1.0 above freezing! Last night was a little colder than the preceeding night at -0.5. 105.7 degrees required to get above 3 in 20 days - average of 5.3 per day (rounded up) 74.7 to get above 2 - average of 3.8 per day (rounded up)

Ensembles currently support the 'tightrope' with a 50/50ish split after the weekend for another cold spell or a mild spell with the further East you are the lower the mean ensemble members - which again hints at where we need to look over the next few days. All eyes NE and beckon the oncoming Arctic (or shoo it away if you have had enough cold)

The pattern, to my eye, looks something like the following Rest of this week - cold by day, cool by night, some snow chances as described, the higher up, the better. Friday into Saturday - the irresistable force of the Atlantic meets the immovable object of the Scandi/Russian HP and we end up squeezed between the two for a day or so and a little milder (perhaps a little above average for a day or so) Then, like squeezing a spot (eeew), it gives and HP ridges up from the Azores and leaves us under HP influence on the outer limits of the now descending Siberian HP cell (already at 1050 and growing) - this ridge has been progged consistently now. From here we end up either at the far end of a cold train and rather cold to cold, getting colder or the HP slips alignment N-S and we end up mild looking longingly 100 miles to our East for the cold. Worth bearing in mind is the trouble the Atlantic is having shifting the 1025 Scandi HP - reinforcements are on the way for the Scandi, are they for the Atlantic?

Jan 20 - Feb 19 1991 = 0.45 was the last sub 1 31 day period Feb 1 - Mar 3 1986 (31 day period) = -0.99, last 31 day sub-zero period

Hadley at -1.6 (-1.56) to the 9th, yesterday was the 7th negative day in a row (second time this winter) Last night -3.5 so today likely to be another negative day. This looks like the lowest we will get to I think - a slow climb back towards -1 over the next few days, but still likely to be sub zero at mid month and perhaps out to the 20th depending on things from Thursday onwards. For sub 3 hunters, 105 degrees over the next 22 days required to get above 3, so 4.7 per day

12z sees the first Atlantic low slide under and the second barrel along through France with no breakdown to mild from either. Uppers will rise briefly above 0 on this run in the West and South before returning to between 0 and -5 throughout in an E to SE flow. Scandi High more aligned for cold winning and further west on this run.

Hadley at -1.5 (-1.54) to the 8th Last night is down as -4.6 so today will likely come in at around -1.5 to -2.0 overall Low point for the month therefore likely now to be -1.7 or thereabouts? Should be comfortably sub-zero at mid-month.

Not really - whilst each model toys with an Atlantic attack, none of them show the attack succeeding in a change of pattern - it is still cold, the Scandi high is still in place and the Atlantic still generally held at bay. Battleground, winner to be decided

By T168 we are in limbo with a ridging Azores (displaced) and a Scandi in place - very similar to the GFS solution actually for me.

For trend spotters, the following should be watched for as they are now recurring on GFS operationals and are a good guide to what we might expect. On Tuesday of next week, an area of LP attacking into the SW but making very minor inroads and dropping snow along a to-be-determined line en route. This is pushed through under cutting the sagging Scandi HP which holds on over S Norway/Sweden at 1025-1030mb propped by the sliding LPs The LP pushing through drags an Easterly or ESE flow back across us and -5s or thereabouts drop back in Azores High throws up a tenative ridge to the West of Ireland which may be of future benefit Deeper FI - signs of a renewed HP rise to the NE and perhaps the NW At best for 'milder' weather the GFS suggests the South coast may struggle up to around average for a day or two next week as the LP slide under us

The coldest first half of Jan is (I think) Jan 1814 at -3.7 1-16th (-3.8 1-15th) so a little extra drop needed! We might graze the low -2s and at mid month be perhaps between -1 and -1.5? We could be sub-zero still by the 20th even with a slightly less cold set-up and sub 2 for the month looks very feasible.

Hadley stands at -1.3 (-1.26) to the 7th with yesterday coming in at -3.9, the coldest CET day since December 1995 With yesterday's maxima at -0.2, it was also a CET ice day Last night was a balmy -7.1

And here comes the cavalry at T252 with bitter cold streaming towards Scandi