Manchester Winter Index to hit a new low?

[Weather-history]

This is the equation I devised to measure the "wintriness" of a winter.

10 x [(the number of days with lying snow)+(number of days with falling sleet/snow)+(number of days where the temperature has been at below 0C)] divided by the mean maximum temperature.

At the moment it is just 7.

I have only recorded 3 air frosts since the 1st December. I saw falling snow for the first time last Tuesday (11th February)

This winter has been an absolute shocker for wintriness. Even 1988-89, I saw lying snow at the back end of February, I saw lying snow during 1989-90. In 1997-98, I saw lying snow at the start of December. This winter, nothing except slight patchiness from Tuesday's brief fall. Looking at the charts, snow and frost prospects look extremely limited at best.

Least wintriest winters of recent times

2013-14: 7 up to 17th February

1988-89: 20

2006-07: 21

1997-98: 25

1974-75: 26

1989-90: 26

1973-74: 30

1987-88: 37

2007-08: 37

1991-92: 40

1975-76: 41

1999-00: 42

1992-93: 43

2002-03: 44

1994-95: 45

1998-99: 47

2004-05: 47

2011-12: 47

2001-02: 50

2003-04: 50

Edited February 18, 2014 by Weather-history

[reef]

Using the same index for the last 27 winters here:

 

2009/10: 1612010/11: 1231995/96: 1082012/13: 971990/91: 852000/01: 702008/09: 611993/94: 612005/06: 542003/04: 502002/03: 491996/97: 471998/99: 461992/93: 452011/12: 432004/05: 412001/02: 391991/92: 391994/95: 311999/00: 311987/88: 282007/08: 212006/07: 181997/98: 161989/90: 91988/89: 82013/14: 5 (to Feb 18th)

 

I think it says it all really. As mentioned in the other thread, all this winter has to its name is 4 air frosts. There hasn't been a single day of sleet and snow. Even 1988/89 managed one day of sleet but there had already been lying snow in November.

[I remember Atlantic 252]

But should it not include Nov, Mar and April? 3 months where snow and frost possible,

[The PIT]

But should it not include Nov, Mar and April? 3 months where snow and frost possible,

Nope as they're not Winter months hence the name Winter index

[johnholmes]

But should it not include Nov, Mar and April? 3 months where snow and frost possible,

 

You can extend winter or summer into any months you wish of course. However, unless we have a specific season list, as per Met office then there can be no seasonal comparisons that mean anything. One could carry this over and say periods of 5, 10, 20, 30 days with temperatures above/below a certain value, rather than the monthly data?

[I remember Atlantic 252]

Perhaps the 'cold' half of the year, 6 months, 1st Nov to 30th April, then my 2012-2013 likely top

[BornFromTheVoid]

A winter index of about 30 here. Nothing exceptional, but fairly poor.

[The PIT]

Winter index of 1 here rounded up.

[Lake District Blizzard]

For my location based on the formula

 

winter 2012/13 scored 137

 

winter 2013/14 scores 13 so far

[AderynCoch]

That really is a shocking figure. This winter may not even reach double-figures never mind match 88/89's final index of 20, and that season is regularly held up as the quintessential antiwinter.

 

Unbelievably poor.

[Weather-history]

Using the same index for the last 27 winters here:

 

2009/10: 1612010/11: 1231995/96: 1082012/13: 971990/91: 852000/01: 702008/09: 611993/94: 612005/06: 542003/04: 502002/03: 491996/97: 471998/99: 461992/93: 452011/12: 432004/05: 412001/02: 391991/92: 391994/95: 311999/00: 311987/88: 282007/08: 212006/07: 181997/98: 161989/90: 91988/89: 82013/14: 5 (to Feb 18th)

 

I think it says it all really. As mentioned in the other thread, all this winter has to its name is 4 air frosts. There hasn't been a single day of sleet and snow. Even 1988/89 managed one day of sleet but there had already been lying snow in November.

 

Looking at the figures, it looks as though low lying northern England at least has had a very poor winter, frost and snow wise. Not sure how other regions have done, Tipperary according to Born..... has had a poor winter but not exceptionally bad.

 

It has been a very frustrating winter if you love snow, it feels as though everything has been there or thereabouts but just on the wrong side of marginal on most occasions. Also any cold spells have been reduced to almost nothing. The early December northerly, the "easterly" at the end of January. Around Christmas was very close but not quite there. I'm surprised that very short coldish spell week last Tuesday (11th Feb) managed to hold on, the way this winter turned out.

 

I wrote this winter off at the end of January because of the above, it felt as though the dice were loaded against, the cards were stacked against at least in this neck of the woods. We were constantly been dealt with a 7 high card hand in a game of poker.

Edited February 19, 2014 by Weather-history

[johnholmes]

Winter index of 1 here rounded up.

how about a 'real' figure Pit?

not got round to doing mine yet but the formula does give a very good indication, be it good or bad I have found since WH first posted the idea in here several years ago.

Edited February 19, 2014 by johnholmes

[Terminal Moraine]

Using the same index the value here for this winter stands at 14.5. For comparitive purposes the winter of 1988/89 had a value of 11.4 and that of 1978/79 came in at 488.1. 2009/10 was 198.2.

[Stargazer]

The winter index here stands at 10 here - not the slightest sign of any wintry precipitation since last April, 9 air frosts and an average maximum of 9 deg C.  Reminds me of an average early 90s winter when I lived in Southampton, when we often went for two or three years in a row when it rained while the rest of the country had sleet and snow.  Although we have hardly done well for air frosts here in Reading this winter, I guess we have had more calm clear nights so we have had more frosts than many areas further north.

Edited February 19, 2014 by Stargazer

[The PIT]

Going to correct mine as i made a mistake while doing it my head. The index is 7 rounded up.

[March Blizzard]

Using the same index the value here for this winter stands at 14.5. For comparitive purposes the winter of 1988/89 had a value of 11.4 and that of 1978/79 came in at 488.1. 2009/10 was 198.2.

Wow, 78/79 must have been extraordinary in your neck of the woods - 2009/10 was certainly no slouch and has less than half the score. Edited February 19, 2014 by March Blizzard

[hillbilly]

Wow, 78/79 must have been extraordinary in your neck of the woods - 2009/10 was certainly no slouch and has less than half the score.

It was here too,when I comment'nothing comes close to 78/79,you now know why and that does not include a major blizzard in the third week of march and a cold april!

[cheeky_monkey]

It was here too,when I comment'nothing comes close to 78/79,you now know why and that does not include a major blizzard in the third week of march and a cold april!

dont forget it also snowed in May 79..just to rub salt into the wounds

[Terminal Moraine]

Here's the complete list for my station since it opened in early 1977. Listed in order of severity.

I've assumed that, for the calculation, days with lying snow is the Met' Office definition, if it's lying snow at any time of day then all the figures would be higher.

 

1978/79...488.1

1985/86...208.1

2009/10...198.2

1995/96...177.0

1984/85...147.3

1990/91...130.0

1981/82...126.1

1983/84....91.8

1977/78....89.7

2012/13....82.8

1993/94....80.2

2008/09....80.0

1982/83....74.9

2010/11....73.7

1980/81....71.7

1979/80....65.8

1986/87....65.8

1996/97....54.9

2002/03....43.7

2011/12....39.3

2000/01....38.2

1998/99....36.9

2004/05....34.9

2003/04....32.6

2005/06....32.0

1994/95....31.5

2001/02....28.5

1989/90....28.1

1999/00....27.7

1987/88....27.4

1992/93....23.0

1991/92....18.0

1988/89....11.4

2006/07....11.1

2007/08....10.1

1997/98.....8.0

 

1978/79 definitely in a league of it's own and that's certainly how I remember it.

Edited February 20, 2014 by Terminal Moraine

[Richard2901]

I have calculated the index for my location and got a surprisingly high score of 34.3. It really deserves a score of zero given there's been no lying snow and nothing but slight frosts.

 

Anyway here is how it compares to recent winters here:

 

2005/06: 54.7

2006/07: 57.1

2007/08: 46.4

2008/09: 108.6

2009/10: 331.6

2010/11: 189.1

2011/12: 67.7

2012/13: 153.8

2013/14: 34.3

 

2005/06 gets a much lower score than it deserves because it excludes the excellent snowfall during the first third of March and 2010/11 is also lower than expected because the snow and cold of the last week of November is excluded.

 

2006/07, 2007/08, 2011/12 and 2013/14 all deserve their very low values. I suspect all the 90s winters would do better than these except 97/98 and 91/92 though the latter was much frostier than any of the recent four.

 

If the index could be adapted to include rainfall and rain days then I've no doubt this winter would score as the worst of all time. 1988/89 would score worse for wintriness but it wasn't thoroughly unpleasant like this winter has been.

[reef]

I have calculated the index for my location and got a surprisingly high score of 34.3. It really deserves a score of zero given there's been no lying snow and nothing but slight frosts.

 

Anyway here is how it compares to recent winters here:

 

2005/06: 54.7

2006/07: 57.1

2007/08: 46.4

2008/09: 108.6

2009/10: 331.6

2010/11: 189.1

2011/12: 67.7

2012/13: 153.8

2013/14: 34.3

 

2005/06 gets a much lower score than it deserves because it excludes the excellent snowfall during the first third of March and 2010/11 is also lower than expected because the snow and cold of the last week of November is excluded.

 

2006/07, 2007/08, 2011/12 and 2013/14 all deserve their very low values. I suspect all the 90s winters would do better than these except 97/98 and 91/92 though the latter was much frostier than any of the recent four.

 

If the index could be adapted to include rainfall and rain days then I've no doubt this winter would score as the worst of all time. 1988/89 would score worse for wintriness but it wasn't thoroughly unpleasant like this winter has been.

 

It just shows the difference between here and up in Aberdeen when 2011/12 which you describe as a poor winter would be the 7th best in 27 years here!

 

2009/10 must have been quite something too.

[summer blizzard]

I don't know what scores they get but the past 10 winters i'd rank as follows..

 

09/10 - By quite a margin - 31 consecutive days with snow on the ground plus an additional 10-15 - 29cm hit

10/11 - 25 consecutive days with snow on the ground - 23cm hit

12/13 - Even excluding March we get 11 days of consecutive snow on the ground and probably above 23cm (i never got the final measurement but i recorded 16cm before the final front which was the heaviest and dumped 12cm elsewhere in Leeds)

08/09 - 16 days lying snow - 16cm

05/06 - Cool, dry, 30+ frosts

04/05 - Falling snow on 14 consecutive days

11/12 - 8 days lying snow, 2 week frigid spell

03/04 - A few topplers but largely unremarkable

07/08 - A pretty poor winter but a few topplers

06/07 - Horrific bar 2 fronts in February

13/14 - No lying snow, only 3 snow showers

[Interitus]

Slight drawback with the formula is that it is poorly behaved with division by the mean maximum temperature if using Celsius (or any scale with negative values particularly close to those recorded) the results are strongly nonlinear and discontinuous - degrees Kelvin would be better.

Edited February 21, 2014 by Interitus

[Nick L]

Slight drawback with the formula is that it is poorly behaved with division by the mean maximum temperature if using Celsius (or any scale with negative values particularly close to those recorded) the results are strongly nonlinear and discontinuous - degrees Kelvin would be better.

 

That would probably be better, although getting a negative mean maximum in this country would take some doing!

[Interitus]

The function gives exponential results, so two identical winters bar for negligibly mean temperature differences eg. 0.001 and 0.00001 would have massively different scores, and of course 0°C would be infinite.

Having a linear function based on degrees K can suffer from a lack of variation in results so nonlinear is not necessarily bad as can emphasize mild/cold extremes. Some bonkers logarithmic function (bear with me here) such as log273(temp°K)^n where n is some large number, means that the values are centred on freezing where the division is 1. 

So for example with a snow/frost etc score of 100 and n=500

Temperature	Score10°C	4.09092019479.5°C	4.78464372999°C	5.59783495878.5°C	6.55138341078°C	7.669886617.5°C	8.98231811537°C	10.52281769526.5°C	12.33162629456°C	14.45619271235.5°C	16.95248398565°C	19.88653752584.5°C	23.33630025874°C	27.39380861543.5°C	32.16777346653°C	37.78664632092.5°C	44.40225770122°C	52.19413603181.5°C	61.37463617971°C	72.19503165620.5°C	84.95275420030°C	100-0.5°C	117.7539643107-1°C	138.7090170938-1.5°C	163.4511931813-2°C	192.675443388-2.5°C	227.2061803434-3°C	268.0217575009-3.5°C	316.2836452969-4°C	373.3712189728-4.5°C	440.9232531994-5°C	520.8874354636-5.5°C	615.5794705304-6°C	727.7536610595-6.5°C	860.6872253244-7°C	1018.2810648705-7.5°C	1205.1802384506-8°C	1426.9180525189-8.5°C	1690.0884657266-9°C	2002.5524527433-9.5°C	2373.6851146255-10°C	2842.8184161331