January 2019 C.E.T. forecast and EWP contests

[Summer Sun]

5.4c to the 14th

1.9c above the 61 to 90 average
1.0c above the 81 to 10 average

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Current high this month 8.0c to the 1st

Current low this month 3.3c to the 4th & 5th

[The PIT]

Sunny Sheffield up to 6.1C +1.6C above normal. Rainfall unchanged.

[Roger J Smith]

Assuming 5.5 C after corrections for 1st to 15th, I estimate average for 16th-31st from GFS 12z to be 2 C (and possibly lower) so that would get us to about 3.7 C by month's end. ECM looks a bit colder than that for as far as it goes. 

Hadley EWP tracker had only managed to find 2 mm to 13th -- still below the record low for the month. The GFS run does not promise much overall, usually a dry regime with localized snow will add up to only 10-20 per cent at most. 

Edited January 15, 2019 by Roger J Smith

[The PIT]

8 minutes ago, Roger J Smith said:

Assuming 5.5 C after corrections for 1st to 15th, I estimate average for 16th-31st from GFS 12z to be 2 C (and possibly lower) so that would get us to about 3.7 C by month's end. ECM looks a bit colder than that for as far as it goes. 

Hadley EWP tracker had only managed to find 2 mm to 13th -- still below the record low for the month. The GFS run does not promise much overall, usually a dry regime with localized snow will add up to only 10-20 per cent at most. 

The lowest here is 1997 with only 6.1mm I think that record is safe though but if it keeps up we will need to hope for a very wet spring otherwise there's trouble this summer.

[Summer Sun]

5.5c to the 15th

2.0c above the 61 to 90 average
1.1c above the 81 to 10 average

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Current high this month 8.0c to the 1st

Current low this month 3.3c to the 4th & 5th

[NorthYorksWeather]

5.2c here to the 15th, 1.7c above the 1981-2010.

Rainfall remains unchanged at 3.6mm

All downhill from here temp wise.

[The PIT]

Sunny Sheffield up 6.2C +1.7C above normal. Rainfall unchanged. GFS on the cold side although night time temps here will mostly normal or just above while day time will be below. Hopeful the ECM will lead the way it seems to be indicating more a block in lala land.

[Summer Sun]

5.7c to the 16th

2.2c above the 61 to 90 average
1.3c above the 81 to 10 average

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Current high this month 8.0c to the 1st

Current low this month 3.3c to the 4th & 5th

[The PIT]

Sunny Sheffield still at 6.2C +1.7C above normal. Rainfall up to a massive 4.2mm 5.2% of average. GFS drifted slightly towards a less cold outlook than previously so going to struggle to get down to average.

[Optimus Prime]

15 minutes ago, The PIT said:

Sunny Sheffield still at 6.2C +1.7C above normal. Rainfall up to a massive 4.2mm 5.2% of average. GFS drifted slightly towards a less cold outlook than previously so going to struggle to get down to average.

Really? Might want to try recalculating that.

That surprises me because here in N.Manchester we dropped to +0.7C this morning and it only went up to about 5C. Even a daily value of 5C would have struck 0.1C of that value. 

[The PIT]

1 hour ago, Optimus Prime said:

Really? Might want to try recalculating that.

That surprises me because here in N.Manchester we dropped to +0.7C this morning and it only went up to about 5C. Even a daily value of 5C would have struck 0.1C of that value. 

If the GFS is correct that is. Also remember when get further and further into a month it's harder to knock large amounts off. You can check this yourself on a calculator. I think the GFS is tracking down the wrong line BTW.

[DAVID SNOW]

As it stands sub 4c very likely, could even get below 3c after corrections.

(puts tin hat on in case of flack)

[Roger J Smith]

Even if we started the January contest today, we would probably get the same range of forecasts and not have any idea who was right, the models are stumbling around like the six blind men with the elephant at this point, although there is a general consensus towards cold, just the details keep changing from run to run and model to model. I am not convinced that the CET will get lower than 4 yet, although it could go as low as 2 if cold is both strong and sustained. The math is as follows, assuming the 5.7 to 16th is really 5.5, after adjustments, then 

17-31 avg 4.0 brings CET to 4.8

17-31 avg 3.0 brings CET to 4.3

17-31 avg 2.0 brings CET to 3.8

17-31 avg 1.0 brings CET to 3.3

17-31 avg 0.0 brings CET to 2.8

17-31 avg -1.0 brings CET to 2.3

17-31 avg -2.0 brings CET to 1.8

17-31 avg -3.0 brings CET to 1.3

and you can calculate what intermediate values would produce, every 0.2 you add to each level adjusts the CET up by 0.1, example, if you wonder what 4.4 will produce, then it's 4.8 + 0.2 = 5.0 C. 

[kold weather]

I think regardless of whether we get a full body easterly, the flow is looking cold from the 21st onwards, I should think from the 21st onwards we should be able to average 2C at least, probably WAY lower than that if some of the 00z suite are correct. Then it just depends on how the next few days turn out.

Odds are good at the moment we will end up with a CET ice day at some point.

If I was a betting man, I'd say somewhere close to 3C might be the landing point.

Edited January 18, 2019 by kold weather

[Summer Sun]

5.5c to the 17th

2.0c above the 61 to 90 average
1.1c above the 81 to 10 average

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Current high this month 8.0c to the 1st

Current low this month 3.3c to the 4th & 5th

[summer blizzard]

3.4 is the goal.

[Man With Beard]

40 minutes ago, Summer Sun said:

5.5c to the 17th

2.0c above the 61 to 90 average
1.1c above the 81 to 10 average

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Current high this month 8.0c to the 1st

Current low this month 3.3c to the 4th & 5th

It will need to average less than 1C for the rest of the month to get the overall below 3C. Possible but hard work - would need the very best charts to verify. Somewhere between 3C and 4C looks a very happy place at the moment. A couple of mild sectors, just maybe, could even keep it around 4C by month's end?

[kold weather]

Interesting Man, both the GFS op and the Para run would average 1C (and probably below!) even accounting for the next few days over that period, at least 4-5 CET Ice days in both sets. Any decent widespread snow cover will tip us towards that level as well.

I personally think something close to 3C will be the end point, but I wouldn't rule out sneaking below that if this does deliver.

[NorthYorksWeather]

4.8c here to the 17th, 1.3c above the 1981-2010 average.

[The PIT]

Sunny Sheffield at 6C +1.6C above average. Rainfall Unchanged. A colder GFS tonight with a hint of colder weather still by next weekend.

[Optimus Prime]

3 minutes ago, The PIT said:

Sunny Sheffield at 6C +1.6C above average. Rainfall Unchanged. A colder GFS tonight with a hint of colder weather still by next weekend.

My calculator still disagrees. Does Sheffield currently have a forest fire burning under its shield? lol

Edited January 18, 2019 by Optimus Prime

[damianslaw]

Its been a long time since we had a January that had a very mild first half compared to a very cold second half.. anyone post stats to back up when this last happened. Came close in 1996, but the cold arrived in the last third rather than 16th. 

Had a number of Februarys that have a seen a flip between cold/mild mid month, 2005, 2009 and 2012 a very good example.

[summer blizzard]

 

1 hour ago, damianslaw said:

Its been a long time since we had a January that had a very mild first half compared to a very cold second half.. anyone post stats to back up when this last happened. Came close in 1996, but the cold arrived in the last third rather than 16th. 

Had a number of Februarys that have a seen a flip between cold/mild mid month, 2005, 2009 and 2012 a very good example.

As recently as 2013. The first half was milder than than this year.

[damianslaw]

19 minutes ago, summer blizzard said:

 

As recently as 2013. The first half was milder than than this year.

Oh I hadn't realised how mild, interesting how we also saw a SSW early that month. Didn't the cold weather set in a little earlier around the 12/13th and fizzled out before months end.

[Roger J Smith]

The EWP tracker from Hadley has reached 9 mm (gasp) and threatens to break into double digits at any point in time. Seriously, there's maybe 20 mm more showing on the charts at the moment (aside from the odd localized 50 mm in snow equivalent we hope). At the rate it's climbing, it may not even make it to our lowest forecast but perhaps it will.

As to cold second halves of January, this is the gold standard top 17 (with ties), of January CET declines from the value reached on the 17th to the finishing values ... at least for the period 1772 to 2018 ...

1 _ 1950 _ 7.6 to 4.2 (drop of 3.4)

2 _ 1873 _ 7.8 to 5.2 (drop of 2.6)

3 _ 1996 _ 6.8 to 4.3 (drop of 2.5)

4 _ 1855 _ 4.7 to 2.4 (drop of 2.3)

t5 _ 1870 _ 5.5 to 3.3 (drop of 2.2) and 1947 _ 4.4 to 2.2 (drop of 2.2) and 1992 _ 5.9 to 3.7 (drop of 2.2)

t8 _ 1907 _ 5.7 to 3.6 (drop of 2.1) and 1910 _ 5.6 to 3.5 (drop of 2.1) and 1912 _ 5.7 to 3.6 (drop of 2.1)

t11 _1933 _ 4.1 to 2.2 (drop of 1.9) and 1952 _ 4.6 to 2.7 (drop of 1.9) and 1976 _ 7.8 to 5.9 (drop of 1.9)

t14 _1865 _ 3.9 to 2.1 (drop of 1.8) and 1909 _ 5.3 to 3.5 (drop of 1.8) and

____1917 _ 3.4 to 1.6 (drop of 1.8) and 1998 _ 7.0 to 5.2 (drop of 1.8)

____________________________________________________________

They got used to this between 1907 and 1917 (five out of eleven appear in the list).  Three of six in the period 1947 to 1952.

The 1990s managed three for seven (1992 to 1998). Also three of nine in the interval 1865 to 1873.

The other three (1855, 1933, 1976) are fairly well scattered but none before 1855 apparently. Cold came earlier in the Dalton perhaps (if it was coming at all). 

Timeline:

____________ 1855 657073 ______ 1907 09 10 12 17 ____ 1933 ___ 19475052 ___ 1976 ___ 1992 96 98

Several of these led to very cold Februaries, notably 1855, 1917 and 1947. (1895 was cold all through January too).

Edited January 19, 2019 by Roger J Smith