Warm AMO Doing It’s Dirty Work On UK AGAIN, Wet, Wet, Wet!

Written by on October 22, 2013 in Rest of Europe, United Kingdom & Ireland with 2 Comments

Up till recently, many UK sites were below normal for rainfall this October but sure enough, the warm waters surrounding the UK as well as out across the North Atlantic, reflective of the continued warm AMO has switched the hose on. The turn to the much more active Atlantic pattern has been anticipated as the season progresses and colder air gains more and more ground. While the atmosphere was still largely warm through August, September into the early part of October, the warm waters fed the continuation of ridging over western Europe but it’s as the season changes, so does the warm water feedback.

I looked back at several UK sites and in the last 6 October’s, for the most part, only 2 of those months were drier than normal, often it was considerably wetter than normal, particularly in areas to the south and west of the UK and Ireland. I don’t believe Cork, Ireland has seen anything other than wetter than normal for October in the last 6 years with some October’s seeing over 200% the normal rainfall and November was the same. A lot has to do with the warm phase of the AMO (Atlantic Multidecadal Oscillation). Since the 1980s it turned warm and when it’s warm and the Pacific goes from warm back to cold, so rainfall in generally increased here across western Europe but ironically, while the UK turns wetter, so Denmark which is generally in the rain shadow of the UK, it turns drier than normal.

With the mean position of the low centred to the southwest of Ireland now and over the next 10 days, not only do we have copious amounts of moisture lifting up over Ireland and the UK but it’s warm air too and of course the warmer the air, the more moisture is often contained.

I was out on the road at 2.15am this morning and the flooding on one of our back roads was serious, in fact I drove through a flooded stretch in which I really struggled to get through, the water appeared to be up at the level of my front headlights and sure enough a police car sitting at the other side of the flood waters, turned around. I believe the road was closed after that. Other roads locally and across Central Scotland was closed after torrential rain fell overnight. These warm, moisture rich southerly flows have brought heavy, torrential flooding rain to many parts of Ireland and the UK in recent autumn’s and this is just the beginning of more super wet autumn weather. Until the AMO turns around, we expect most autumn to be like this as the atmosphere cools while waters are much warmer than normal.

This chart shows the trend in the AMO.

Amo_timeseries_1856-present_svg

Here’s the ECMWF total precipitation over the UK through the next 7 days. Plenty more rain to come!

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

[s2If current_user_can(access_s2member_level1)]

Here’s Europe. A LOT of rain is also expected down over western Iberia as well as up over southern Norway.

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

From now through probably the first 10 days of November, the parade of Atlantic lows will continue to sweep heavy rain and wind bearing fronts across Iberia, Ireland/UK Norway.

Here’s the ECMWF surface chart for the coming week t0 10 days! Have the brolly and wellies handy!

60 hr

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

90 hr

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

Notice by 120 hrs the model has at least 3 sub-985mb centres lined up over the Atlantic!

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

What will be interesting is whether the system begins to deeper more and more as the +NAO signal kicks in with Greenland becoming much colder again while warmer air tries to lift north. Remember that as the jet speeds up and becomes wavy, the atmosphere is much more conducive for rapid deepening of lows as they approach Ireland and the UK and tap bitterly cold air off Greenland and still warm air from Africa, keeping in mind the warmer than normal waters which span the North Atlantic from Canada to Norway.

Sure enough, check out the 216 hr right at the close of the month.

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

The GFS shows a similar idea for the same time period.

Courtesy/Owned by AccuWeather Pro

Courtesy/Owned by AccuWeather Pro

This much more active pattern is likely to continue with the NAO and AO flipping back positive. I expect much of November to be warmer and considerably wetter than normal. Don’t be surprised if we see worsening flooding situations with perhaps a few big storm systems in the 2-3 week period.

nao_sprd2

The GFS ensemble shows the strongest positive of the year! This will help really build arctic air over the pole.

ao_sprd2

The ECMWF shows a classic +AO signal by October 30.

EDH1-192

Rest easy cold weather lovers. This is NOT a bad pattern to take us into the heart of autumn.

Had we seen a cold, dry October, November then I would have said we’re either heading for a front ended winter which is over before it starts or we don’t get any winter at all. Even look back at 2010-11 and although it was the coldest December in 100 years, winter was done by New Year.

In October 2007, it was dry and that winter which followed was one of Europe’s warmest.

The best winter we can hope for is one like 2009-10 which had a neutral ENSO, like we have now.. we have similar arctic sea ice extent and early expansive Asian snow cover plus it was VERY wet and mild to end October and through most of November!! Though there’s no guarantee’s, I urge you to be patient.

The latest CFS sees the +NAO and warmer, wetter Europe pattern but check out December!

cfs-3-11-2013

cfs-3-12-2013

Look at January!!

cfs-3-1-2014

[/s2If][s2If is_user_logged_in() AND current_user_cannot(access_s2member_level1)]

That’s it, [s2Get constant=”S2MEMBER_CURRENT_USER_DISPLAY_NAME” /]!

To continue reading, you need to have a valid subscription to access premium content exclusive to members. Please join a subscription plan if you would like to continue.[/s2If][s2If !is_user_logged_in()]

Sign in to read the full forecast…

Not yet a member? Join today for unlimited access

Sign up to markvoganweather.com today to get unlimited access to Mark Vogan’s premium articles, video forecasts and expert analysis.
[/s2If]

Tags: , ,

Follow us

Connect with Mark Vogan on social media to get notified about new posts and for the latest weather updates.

Subscribe via RSS Feed Connect on YouTube

2 Reader Comments

Trackback URL Comments RSS Feed

  1. Mark Vogan says:

    Just checking that your reading 😉 Haven’t a clue why I keep writing that…

  2. perry says:

    Willies again.

Leave a Reply

Top