The Easterly That Never Was- A Synoptic Recap

[Thundery wintry showers]

As I was doing the 12Z Model Comparisons back in early 2007, I have an archive from N-W of all of the ECMWF and GFS 00Z and 12Z runs out to T+240. I have decided to create a separate thread for this so as not to destroy the flow of today's model output discussion thread.

An analysis of the easterly that never was, focusing on its projected peak day, 23 February:

13 February ECM:

13 February GFS:

Already at T+240 GFS showed a full-on easterly on its 00Z and a weaker version at 12Z, but ECMWF having none of it, going for SW winds.

14 February ECM:

14 February GFS:

To T+216, GFS dropped the easterly at 00Z but supported one at 12Z, mainly over the south. ECMWF showed mild SWs.

15 February ECM:

15 February GFS:

To T+192, GFS went for the armageddon of easterlies at 00Z, a cold but dry SSE'ly at 12Z. ECMWF SWs at 00Z, but southerlies and continental influence at 12Z.

16 February ECM:

16 February GFS:

To T+168, this is when snow lovers got really excited. The ECM and GFS both went for southerlies at 00Z, albeit not very mild ones, then at 12Z, both models supported the easterly- if anything ECM going for a more potent one than GFS. The rampometer was heading into overdrive.

17 February ECM:

17 February GFS:

To T+144, ECM dropped the easterly again, going for a mild southerly influence, though continental air not far away on its 00Z. GFS started the downgrade but on both 00Z and 12Z runs had continental air influencing Britain, giving cold dry SSE'lys.

18 February ECM:

18 February GFS:

And suddenly, both models agreed on a mild southerly- and goodbye easterly, and hello mass wave of disappointment!

[Sawel]

I still remember this well. The UKMO went up a lot in my estimations after this as it never once went for an easterly whilst the other big two models struggled badly.

[Nick L]

I am glad I wasn't a lurker/member at that time, would have been so gutting!

[Duncan McAlister]

I am glad I wasn't a lurker/member at that time, would have been so gutting!

Probably the biggest disappointment ever during the time I've been reading the models (since early 2006)

Edited December 1, 2008 by Duncan McAlister

[Mark Bayley]

Yep remember that, i even think i have one of the charts saved on my comp somewhere because it was that good. Because of what happened i won't believe it till its down to T6 lol

I did learn my lesson about getting excited about charts in that time frame

Here it is

Edited December 1, 2008 by mark bayley

[Optimus Prime]

January 2005 was a massive dissapointment. If I remember a severe easterly entered the 120 hour time frame, to only be wiped out by 90 odd hours. In the end a perfect set-up did occur later in February that year, but with only a cool continent.

[Sawel]

I remember reading a thread by one of the forecasters about the different types of easterlies that you can get in the UK in winter, ranging from dull and drizzly to prolonged heavy snowfall. I think there were 4 or 5 different types. I can't remember if it was last winter or the winter before that it was posted but it was a great read and had examples.

[SMU]

January 2005 was a massive dissapointment. If I remember a severe easterly entered the 120 hour time frame, to only be wiped out by 90 odd hours. In the end a perfect set-up did occur later in February that year, but with only a cool continent.

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[Don]

January 2005 was a massive dissapointment. If I remember a severe easterly entered the 120 hour time frame, to only be wiped out by 90 odd hours. In the end a perfect set-up did occur later in February that year, but with only a cool continent.

Yes, I remember that and if I remember correctly, the Met Office talked about the possibility of a very cold spell of weather in their 14 day outlook for late January. The cold spell that did arrive in mid-late February 2005 was impressive for its persistance, but wasn't overly cold due to as you say a relatively mild continent. However, for my location, it did produce more snow than at anytime during the following colder Winter!

[Thundery wintry showers]

I think I started that one!

As a general rule, the longer the sea track, the moister the airmass and the lower the pressure, the more moisture will be picked up over the North Sea.

In a stable airmass (upper air temperatures relatively high compared with lower air temperatures) it ends up dry and cloudy because the moisture gets trapped under an inversion and gives stratocumulus- minimal moisture and it may break up to allow sunshine, high moisture and it might get thick enough to produce persistent albeit light precipitation.

In an unstable airmass it means sunshine and showers, with the amount of moisture and the depth of the instability determining how many showers we get, and in some cases if troughs/fronts are around the showers may merge to give spells of prolonged precipitation.

Then we have the issue of whether the temperature at ground level is low enough to support snow, but I think if you get the cold upper air (preferably below -10 at 850hPa) and a wind vectored from between NE and E chances are eastern Britain is going to get a dumping of snow.

[davehsug]

If I remember correctly, it did eventually bring us 1 very cold day with temps just above freezing & a bone chilling wind. Just a taster of what the jet cost us

Dave

[cheeky_monkey]

cant see the point really..these charts occur all the time in the models during the winter.

What should be noted is how often they are not fullfilled..so why people get all exicted and start talking about snow potential and sustained cold everytime is beyond me..do people not learn??

[Optimus Prime]

Yes, I remember that and if I remember correctly, the Met Office talked about the possibility of a very cold spell of weather in their 14 day outlook for late January.

I vaguely remember at the end of the Thursday or Friday forecast one forecaster can't remember who mentioned the prospect of much colder weather taking hold later next week. Tis of course never happened, if that easterly that Steve shown had materialised it would have resulted in a cold February.

[Thundery wintry showers]

The other source of frustration was that since I started as a forecaster on N-W I have gone for very cold "Siberian" north-easterlies in two LRFs- as it happens, January 2006 and February 2007. In both cases I predicted that they would arrive sometime around the 20th.

I was agonisingly close to being spot on with both of those predictions, and leading up to those projected easterlies was preparing to get a pat on the back for my accurate forecasting, but in the end, they didn't come off- and therefore, neither did the entire last third of my respective forecasts.