De zomer van 2012!

[Sebastiaan]

Grote kans op warmte/hitte in West Europa deze zomer.

Weather Services International: Warmth Focused in Western and Northern Europe This Summer

Emerging El Nino, Lack of Atmospheric Blocking and Cooler North Atlantic Should Result in Much Different Pattern Relative to 2008-11 Summers

Andover, MA, April 23, 2012 — WSI (Weather Services International) expects temperatures for the upcoming period (May-July) to average higher than normal across all of Europe, with the exception of parts of the Southeast.

“While April has been a relatively cool month across much of Europe, we expect more widespread, above-normal temperatures to develop in May, especially across eastern and northern sections,” said WSI Chief Meteorologist Dr. Todd Crawford. “As we head into the summer period, we expect a distinctly different pattern than what we’ve observed over the last four years, when very warm summer temperatures were focused over southern/eastern sections of Europe with near-normal temperatures in Western Europe. The combination of an emerging El Nino event, an expected lack of North Atlantic blocking and relatively cool North Atlantic ocean temperatures should result in a reversal of recent summer patterns. Specifically, the combination of these factors should result in greater chances for summer heat in western and northern sections, rather than southern and eastern sections. Further, relative to recent years, we expect a drier summer in the UK and Nordic regions and wetter weather suppressed farther to the south. Finally, our forecast also supports less wind across Germany/Denmark and more wind in Spain than we’ve had the last four summers.”

In May, WSI forecasts:

Nordic Region* – Warmer than normal
UK* – Warmer than normal
Northern Mainland* – Warmer than normal
Southern Mainland* – Warmer than normal

In June, WSI forecasts:

Nordic Region – Warmer than normal
UK – Warmer than normal
Northern Mainland – Warmer than normal
Southern Mainland – Warmer than normal, except Southeast

In July, WSI forecasts:

Nordic Region – Warmer than normal
UK – Warmer than normal
Northern Mainland – Warmer than normal, except parts of Northeast
Southern Mainland – Warmer than normal, except parts of Southeast

[Oud-forumlid]

Grote kans op warmte/hitte in West Europa deze zomer.

Dachten ze dat in 2011 ook niet?

[Gerard]

Ook wel toch? Niet? Ja dat wordt dubben: wanneer op vakantie? Wanneer slaat de moesson dit jaar toe?

[Sebastiaan]

Ook wel toch? Niet? Ja dat wordt dubben: wanneer op vakantie? Wanneer slaat de moesson dit jaar toe?

Als je maar niet naar Zuid-Europa gaat, West-Europa is 'safe'

[Vincent]

Mooi. Alvast een mooie basis voor het Inferno.

[Gert]

Volgens mij moeten we al weer een aantal jaren terug voor de laatste landelijke hittegolf. 2012 een koudegolf in februari die er mag zijn gevolgd door een hittegolf die op 2006 lijkt. Alles kan in het huidige klimaat

[Oud-forumlid]

Waarom geen aaneengebreide langdurige hittegolf à la:

juni/juli 1976 - juli 2006 - augustus 2003

[Oud-forumlid]

Waarom geen aaneengebreide langdurige hittegolf à la:

juni/juli 1976 - juli 2006 - augustus 2003

Omdat we 's winters ook nog nooit een aaneengebreide langdurige koudegolf hadden a la:

november 1993, december 1788, januari 1823, februari 1956, maart 1845.

[John]

Waarom geen aaneengebreide langdurige hittegolf à la:

juni/juli 1976 - juli 2006 - augustus 2003

Nog altijd hittegolf nummer 1, die uit zomer 1976, als we duur en aantal tropische dagen combineren.

[Sebastiaan]

http://www.metoffice.gov.uk/media/pdf/3 ... mp-MMJ.pdf

SUMMARY - TEMPERATURE:
The balance of probability, both for May and the period May-June-July 2012, favours UK-averaged temperatures above the 1971-2000 climate mean, but in line with those observed over the last ten years.

However, predictability for both periods tends to be low, with current forecasts indicating greater-than-average uncertainty in UK weather patterns as early as the beginning of May. May is also a month where there can still be large swings in temperature depending on the prevailing wind direction and so cold spells are still possible despite the most likely scenario being for above-normal temperatures.

The probability that the UK-mean temperature for May-June-July will fall into the coldest of our five categories is less than 5%, whilst the probability that it will fall into the warmest of our five categories is around 45% (the 1971-2000 climatological probability for each of these categories is 20%)

Factors that are known to influence the UK’s climate currently provide no clear signal regarding the likely circulation types across the North Atlantic and Europe through the coming months. The La Niña event that has influenced the world’s weather for the last two years has finally decayed and there is an expectation that there will be a transition to weak El Niño conditions in the coming months.

May is typically a variable month across the UK and the extent of predictability is often reduced relative to ‘normal’. This year is no exception, and there exists greater-than-average uncertainty over the prevailing circulation patterns to influence the UK from as early as the first week of May, with computer model predictions offering
mixed and conflicting signals.

The shift of the forecast probability curve on the right-hand panel of Figure T2 towards the warm side of the 1971-2000 mean
temperature is consistent with climate warming and is in line with the range of May-June-July periods experienced in the last decade.

A further supporting factor for above-normal temperatures may also be sea surface temperatures around the UK, which are
currently above average despite the cooler weather that has occurred during April. However Figure T2 also shows a small but
significant cluster of possible outcomes for a May-June-July period somewhat colder than observed during the last decade. It is also not possible to rule out a very warm season in which ‘heatwave’-type conditions become established.
The very unsettled and often chilly weather experienced during recent weeks is predicted to ease as we enter May, with
temperatures likely to increase to at least normal for this time of year.

-> Bijna 50% kans op een flink te warme mei-juni-juli.