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Met office Contingency planners forecasts


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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

At the very least a moderate El Niño event with the largest anomalies over the eastern Pacific is expected.

 

So this suggests the Met Office currently does not expect a Modoki type El Nino to develop?

Currently the east is warmer although its basin wide.

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Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire

Currently the east is warmer although its basin wide.

I know it is currently but some models are predicting it to become more west based later in the year. However, it would appear that the Met Office does not see this as the most likely outcome at the moment?

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

July update issued

 

August to October

 

Summary Temperature

 

For August near- to below-average temperatures are most likely. For August-September-October, although above-average temperatures are more probable than below-average, uncertainty is large. Overall, the probability that the UK-mean temperature for August-September-October will fall into the coldest of our five categories is around 20% and the probability that it will fall into the warmest of our five categories is around 25% (the 1981-2010 probability for each of these categories is 20%)

 

El Niño is now firmly established with sea surface temperatures in the eastern tropical Pacific Ocean continuing to rise. Climate models suggest that sea surface temperatures will remain above El Niño thresholds for the rest of the year and that a moderate to strong event is likely. However, El Niño is not known to have a significant influence on the climate across northern Europe at this time of year. In the North Atlantic, sea surface temperatures to the south of Greenland and in the tropics are colder than in recent years; this pattern of sea surface temperatures is thought to increase the probability of above-average pressure over northern Europe in summer and early autumn. Computer model signals are quite strong regarding the most probable atmospheric circulation pattern, with higher-than-average pressure favoured near the UK during August and August-September-October as a whole. Usually, at this time of year, higher-than-average pressure is associated with above-average temperatures.

 

However, the position of the high pressure in relation to the UK is a factor to consider. During August, models are in good agreement in suggesting that pressure will be higher-than-average to the west of the UK, which would allow more of an Atlantic influence than if the high pressure was centred over northern Europe. As already noted above, sea surface temperatures are colder-than-average in the North Atlantic and this lends some support to the increased likelihood to below-average temperatures during August

 

Beyond August, it is less clear where the areas of high pressure will be located in relation to the UK and therefore whether above- or below-average temperatures are more likely. Having said that, computer models are consistent in having a small signal for above-average temperatures. This can be seen in the right hand graph in figure T2 which shows an increased likelihood of above-average temperatures but also a broad range of solutions. It is worth noting that the probability of below-average temperatures is similar to climatology.

 

Temperature Summary

 

 

Summary Precipitation

 

The latest predictions for UK precipitation favour below-average rainfall for August and August-September-October as a whole. The probability that UK precipitation for August-September-October will fall into the driest of our five categories is around 30% and the probability that it will fall into the wettest of our five categories is 15% (the 1981-2010 probability for each of these categories is 20%)

 

Sea surface temperatures in the North Atlantic have been shown to influence rainfall in northern Europe during summer. The current pattern is associated with drier-than-average conditions in northern Europe, including the UK. Indeed, computer models are consistent in favouring below-average rainfall in the  coming months, with higher-than-average pressure more probable across northern Europe through until the early autumn. This is reflected in the difference between the probabilities for the driest and wettest categories shown in figure P2

 

Precipitation Summary

 

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

August update issued

 

September to November

 

Summary Temperature

 

For September uncertainty is large, with both below-average and above-average temperatures equally probable. For September-October-November as a whole above-average temperatures are more probable than below-average. Overall, the probability that the UK-mean temperature for September-October-November will fall into the coldest of our five categories is 20% and the probability that it will fall into the warmest of our five categories is between 30% and 35% (the 1981-2010 probability for each of these categories is 20%)

 

El Niño continues to strengthen with the ocean and atmosphere now coupled and reinforcing each other. Regional impacts of El Niño, such as reduced rainfall in the Indian Summer Monsoon and drought in the Caribbean, have been observed. Climate models suggest that sea surface temperatures will remain above El Niño thresholds for the rest of the year and that a moderate to strong event is likely. In terms of influence on the weather across the UK, such an event slightly increases the probability of the positive phase of the North Atlantic Oscillation (NAO) in late autumn. The positive phase of NAO towards the end of the period is associated with mild weather.  Another factor which could influence temperatures over the UK is the colder-than-average sea surface temperatures in the North Atlantic. Whilst this cold sea surface temperature anomaly is not known to influence large-scale weather patterns, it could increase the probability of below-average temperatures should winds blow frequently from the Atlantic during the early part of the season

 

Several computer models are in reasonably good agreement, favouring higher-than-average pressure near the UK during September. Usually, at this time of year, this atmospheric circulation pattern is associated with above-average temperatures. However, signals from models, whilst similar, are weak and the colder-than-average North Atlantic (as discussed above) may play a moderating role on temperatures. These factors lead to a temperature forecast where there is a broad range of possible outcomes, with probabilities of above- and below-average almost equal – see left-hand graph in figure T2.

 

Autumn is a transitional time of year; a given circulation pattern can result in different temperature outcomes between the start and end of the season. For example, a pattern dominated by unsettled weather across the UK often results in cooler-than-average conditions in September and milder-than-average in November. Towards the end of the season there is a preference in computer models for cyclonic circulation patterns to be more dominant near the UK, lending some support to the forecast of above-average temperatures for the season as a whole.

 

Temperature Summary

 

Summary Precipitation

 

For September and September-October-November as a whole, the forecast for UK precipitation has a wide spread and its distribution is indistinguishable from climatology. The probability that UK precipitation for September-October-November will fall into the driest of our five categories is around 20% and the probability that it will fall into the wettest of our five categories between 20 and 25% (the 1981-2010 probability for each of these categories is 20%)

 

Autumn is a season when, climatologically speaking, Atlantic depressions become more intense, often carrying large amounts of moisture, making it one of the stormiest and wettest parts of the year (as can be seen in figure P1). During September the lack of strong forcing factors and only weak atmospheric circulation signals from the models leads to a broad range of outcomes in the forecast. The probabilities of above- and below-average rainfall do not differ significantly from climatology; this can be seen in the left-hand graph in figure P2.

 

As discussed in the temperatures section the ongoing El Niño event may have some influence on the North Atlantic Oscillation (NAO) later in the season, increasing the probability of a positive phase dominating. The positive phase is usually associated with above-average rainfall. However for September-October-November as a whole there is no significant increase in the probability of a very wet season with respect to climatology. The right-hand graph in figure P2 shows that a broad range of outcomes is possible and that there is only a very slight shift towards above-average rainfall.

 

Precipitation Summary

 

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

September update issued

 

October to December

 

Summary Temperature

 

For October uncertainty is large, with both below-average and above-average temperatures equally probable. For October-November-December as a whole above-average temperatures are slightly more probable than below-average. Overall, the probability that the UK-mean temperature for October-November-December will fall into the coldest of our five categories is between 15% and 20% and the probability that it will fall into the warmest of our five categories is around 25% (the 1981-2010 probability for each of these categories is 20%)

 

El Niño continues to strengthen with sea surface temperatures in the tropical Pacific Ocean (east of the International Date Line) rising further in the past month. Seasonal prediction systems suggest that sea surface temperatures will continue to slowly rise and remain well above El Niño thresholds for the rest of the year. This event is already stronger than any since 1997-98 and is very likely  to rank amongst the strongest events in the historical record. In terms of  influence on the weather across the UK, such an event slightly increases the probability of the positive phase of the North Atlantic Oscillation (NAO) in late autumn and early winter. The positive phase of NAO, at this time of year, is associated with milder- and wetter-than-average weather

 

The Quasi-Biennial Oscillation (QBO), an oscillation of the equatorial winds in the stratosphere, has recently changed to a strong westerly phase. The QBO has  a link to conditions over Western Europe during late autumn and early winter by  influencing the strength of the stratospheric polar vortex and thereby the phase of the NAO at the surface. A westerly phase of the QBO tends to favour a stronger stratospheric polar vortex, leading to a higher likelihood of a positive phase of the NAO.

 

North Atlantic sea-surface temperatures continue to show a strong pattern of cooler-than-average conditions in mid-latitudes (north of approximately 40 ̊N) and warmer-than-average conditions further south. While the presence of relatively cool ocean conditions near the UK is expected to moderate temperatures a certain amount, the pattern of North Atlantic temperatures has some similarity to the so-called ‘Atlantic Tripole’ pattern associated with an increased chance of positive NAO

 

The Met Office seasonal prediction system shows reasonably good agreement with systems from other global forecast centres in favouring higher-than-average pressure near or just to the south of the UK during October. However, these signals, whilst similar, are weak. This uncertainty in the atmospheric circulation pattern leads to a temperature forecast where there is a broad range of possible outcomes, with probabilities of above- and below-average almost equal – see left hand graph in figure T2.For October-November-December, the factors described above suggesting an increased likelihood of positive NAO, are reflected in the predictions of the Met Office seasonal prediction system.

 

Predictions from other forecast centres almost all show a similar tendency. This suggests above-average temperatures are more likely than below-average, although the coolness in the North Atlantic tempers this prediction to some extent. As a result, the increase in the likelihood of milder-than-average conditions, and decrease in the likelihood of cooler-than-average conditions, is moderate. This does not preclude occasional spells of colder weather, but these are less probable than is typical at this time of year. The right-hand graph of Figure T2 shows a shift towards milder conditions, with a reduced probability of below-average temperatures and an increased probability of above-average temperatures.

 

Temperature Summary

 

Summary Precipitation

 

For October, the forecast for UK precipitation has a wide spread and its distribution is indistinguishable from the usual range of conditions at this time of year. For October-November-December precipitation is more likely to be above-average than below-average. The probability that UK precipitation for October-November-December will fall into the driest of our five categories is 15% and the probability that it will fall into the wettest of our five categories is 35% (the 1981-2010 probability for each of these categories is 20%).

 

Autumn is a season when, climatologically speaking, Atlantic depressions become more intense, often carrying large amounts of moisture, making it one of the stormiest and wettest parts of the year (as can be seen in figure P1).During October weak atmospheric circulation signals are found in seasonal prediction systems. This leads to a broad range of possible outcomes in the forecast for precipitation. The probabilities of above- and below-average rainfall do not differ significantly from normal; this can be seen in the left-hand graph in figure P2.

 

As discussed in the temperature section, the ongoing El Niño event,  together with the westerly phase of the Quasi-Biennial Oscillation (QBO) and North Atlantic temperatures, are likely to have an influence on the North Atlantic Oscillation (NAO), increasing the probability of the positive phase becoming more prevalent. The positive phase of the NAO is associated with above-average precipitation. The Met Office seasonal prediction system, along with systems from other global forecast centres, supports an increased risk of above-average rainfall. The right-hand graph in figure P2 highlights a clear shift towards above-average precipitation consistent with the predicted shift in the likelihood of positive NAO. This pattern is also associated with an increase in the frequency of Atlantic storms crossing the UK, and spells of windy or stormy weather are more likely than is usual for this time of year.

 

Precipitation Summary

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

October update issued

 

November to January

 

Summary Temperature

 

For both November and November-December-January above-average temperatures are considered more likely than below-average. Overall, the probability that the UK-average temperature for November-December-January will fall into the coldest of our five categories is around 10% and the probability that it will fall into the warmest of our five categories is around 30% (the 1981-2010 probability for each of these categories is 20%).

 

A strong, mature El Niño event is currently occurring in the tropical Pacific Ocean. Seasonal prediction systems suggest it will strengthen further over the next 2 months. Using the frequently cited ‘Niño 3.4 index’ as a measure of El Niño strength, it is more likely than not that the current El Niño will become the strongest event on record by the end of the year. El Niño is already creating wide-ranging weather impacts across the globe. The influence on UK weather, however, is more subtle. El Niño moderately increases the probability of the positive phase of the North Atlantic Oscillation (NAO) in late autumn and early winter and the negative phase of the NAO in late winter. At this time of year, the positive phase of the NAO is associated with milder- and wetter-than-average conditions, whilst the negative phase is associated with colder- and drier-than-average conditions.

 

The Quasi-Biennial Oscillation (QBO), an oscillation of the equatorial winds in the stratosphere, remains in a westerly phase. The QBO influences winter conditions over Western Europe by modulating the strength of the stratospheric polar vortex and thereby the phase of the NAO at the surface. The westerly phase of the QBO tends to favour a stronger stratospheric polar vortex, leading to a higher likelihood of a positive phase of the NAO In the Eastern North Atlantic Ocean, sea-surface temperatures continue to show a strong pattern of cooler-than-average conditions in mid-latitudes (north of approximately 40 ÌŠN) and warmer-than-average conditions further south. This corresponds to a strengthened temperature gradient which would be expected to increase the chance of westerly winds, which are usually associated with mild and wet weather in winter. Further west, very warm water near Newfoundland is also expected to enhance the chances of westerly conditions.

 

The factors described above suggest an increased likelihood of positive NAO, which is supported by predictions from the Met Office seasonal prediction system along with systems from other global forecast centres. Taking all the evidence together, our outlook is illustrated in the graphs below. The right-hand graph in figure T2 shows a clear shift towards milder conditions, with a reduced probability of below-average temperatures and an increased probability of above-average temperatures compared to normal. While there is an increased chance of above-average temperatures for the 3-month period as a whole, the risk of cold spells should not be discounted entirely. In particular, this risk increases at the end of the 3-month period as that is the time of year when sudden stratospheric warming events occur. These events tend to bring cold weather to the UK, and occur more often in El Niño years than in other years

 

Temperature Summary

 

Summary Precipitation

 

For both November and November-December-January above-average precipitation is considered more probable than below-average.The probability that UK-average precipitation for November-December-January will fall into the driest of our five categories is between 10% and 15% and the probability that it will fall into the wettest of our five categories is between 25% and 30% (the 1981-2010 probability for each of these categories is 20%)

 

As discussed in the temperature section, the ongoing El Niño event, together with the westerly phase of the Quasi-Biennial Oscillation (QBO) and North Atlantic temperatures, increase the chances of a positive phase of the North Atlantic Oscillation (NAO) At this time of year, the positive phase of the NAO is associated with above-average precipitation and an increased frequency of Atlantic depressions crossing the UK. The Met Office seasonal prediction system, along with systems from other global forecast centres, supports an increased risk of above-average rainfall. Taking all the evidence together, our outlook is illustrated in the graphs below. The right-hand graph in figure P2 highlights a clear shift towards above-average precipitation with a reduced probability of below-average precipitation and an increased probability of above-average precipitation compared to normal. Furthermore, the risk of spells of windy or even stormy weather is expected to be greater than usual for the time

 

Precipitation Summary

 

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Posted
  • Location: Newton in Bowland
  • Location: Newton in Bowland

October update issued

 

November to January

 

Summary Temperature

 

For both November and November-December-January above-average temperatures are considered more likely than below-average. Overall, the probability that the UK-average temperature for November-December-January will fall into the coldest of our five categories is around 10% and the probability that it will fall into the warmest of our five categories is around 30% (the 1981-2010 probability for each of these categories is 20%).

 

A strong, mature El Niño event is currently occurring in the tropical Pacific Ocean. Seasonal prediction systems suggest it will strengthen further over the next 2 months. Using the frequently cited ‘Niño 3.4 index’ as a measure of El Niño strength, it is more likely than not that the current El Niño will become the strongest event on record by the end of the year. El Niño is already creating wide-ranging weather impacts across the globe. The influence on UK weather, however, is more subtle. El Niño moderately increases the probability of the positive phase of the North Atlantic Oscillation (NAO) in late autumn and early winter and the negative phase of the NAO in late winter. At this time of year, the positive phase of the NAO is associated with milder- and wetter-than-average conditions, whilst the negative phase is associated with colder- and drier-than-average conditions.

 

The Quasi-Biennial Oscillation (QBO), an oscillation of the equatorial winds in the stratosphere, remains in a westerly phase. The QBO influences winter conditions over Western Europe by modulating the strength of the stratospheric polar vortex and thereby the phase of the NAO at the surface. The westerly phase of the QBO tends to favour a stronger stratospheric polar vortex, leading to a higher likelihood of a positive phase of the NAO In the Eastern North Atlantic Ocean, sea-surface temperatures continue to show a strong pattern of cooler-than-average conditions in mid-latitudes (north of approximately 40 ÌŠN) and warmer-than-average conditions further south. This corresponds to a strengthened temperature gradient which would be expected to increase the chance of westerly winds, which are usually associated with mild and wet weather in winter. Further west, very warm water near Newfoundland is also expected to enhance the chances of westerly conditions.

 

The factors described above suggest an increased likelihood of positive NAO, which is supported by predictions from the Met Office seasonal prediction system along with systems from other global forecast centres. Taking all the evidence together, our outlook is illustrated in the graphs below. The right-hand graph in figure T2 shows a clear shift towards milder conditions, with a reduced probability of below-average temperatures and an increased probability of above-average temperatures compared to normal. While there is an increased chance of above-average temperatures for the 3-month period as a whole, the risk of cold spells should not be discounted entirely. In particular, this risk increases at the end of the 3-month period as that is the time of year when sudden stratospheric warming events occur. These events tend to bring cold weather to the UK, and occur more often in El Niño years than in other years

 

Temperature Summary

 

Summary Precipitation

 

For both November and November-December-January above-average precipitation is considered more probable than below-average.The probability that UK-average precipitation for November-December-January will fall into the driest of our five categories is between 10% and 15% and the probability that it will fall into the wettest of our five categories is between 25% and 30% (the 1981-2010 probability for each of these categories is 20%)

 

As discussed in the temperature section, the ongoing El Niño event, together with the westerly phase of the Quasi-Biennial Oscillation (QBO) and North Atlantic temperatures, increase the chances of a positive phase of the North Atlantic Oscillation (NAO) At this time of year, the positive phase of the NAO is associated with above-average precipitation and an increased frequency of Atlantic depressions crossing the UK. The Met Office seasonal prediction system, along with systems from other global forecast centres, supports an increased risk of above-average rainfall. Taking all the evidence together, our outlook is illustrated in the graphs below. The right-hand graph in figure P2 highlights a clear shift towards above-average precipitation with a reduced probability of below-average precipitation and an increased probability of above-average precipitation compared to normal. Furthermore, the risk of spells of windy or even stormy weather is expected to be greater than usual for the time

 

Precipitation Summary

Nicely written and highly informative but no more likely to be right than any other LRF, I feel the +NAO could leave them with egg on their faces myself but I suppose it's only a probability map and nothing more.

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Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

When I looked at El Nino events over 20th century I too saw no real bias but I certainly didn't see increased chances/correlation of a cold snowy winter with strong El Nino.  So on the basis of their analysis I certainly see where they are coming from but it isn't the only driver and there is no definitive outcome....fortunately.

 

BFTP

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

November updated issued

 

December to February

 

Summary Temperature

 

 

During December above-average temperatures are more likely than below-average temperatures. The likelihood of a prolonged spell of cold weather is relatively low compared to normal. Predictions for UK-mean temperature for the whole of the winter season (December-January February) show only a slight shift from the normal range of expected conditions. In this instance, however, there are reasons to believe that this unremarkable outlook conceals the likelihood of a switch from a mild start to winter towards colder conditions later on.

 

These different phases balance the probability of above- and below-average conditions in the overall 3-month average, but that does not imply normal chances of weather impacts this winter. Specifically, we consider there to be an increased risk of storms and very wet conditions in the early part of the winter, and a greater risk of cold weather impacts in late winter. Overall, the probability that the UK-average temperature for December-January-February will fall into the coldest of our five categories is 15% and the probability that it will fall into the warmest of our five categories is between 20% and 25% (the 1981-2010 probability for each of these categories is 20%). As stated above, however, these overall statistics disguise a shift in probabilities as winter progresses.

 

A strong, mature El Niño event continues in the tropical Pacific Ocean. Seasonal prediction systems suggest it will strengthen slightly before the end of the year. This El Niño is comparable in strength to the 1997-98 and 1982-83 events and is highly likely to rank among the three strongest on record. El Niño is already creating wide-ranging weather impacts across the globe. The influence on UK weather, however, is more subtle. El Niño moderately increases the probability of the positive phase of the North Atlantic Oscillation (NAO) in early winter. At this time of year, the positive phase of the NAO is associated with milder- and wetter-than-average conditions, whilst the negative phase is associated with colder- and drier-than-average conditions. In late winter El Niño increases the probability of sudden stratospheric warming events occurring. These events disrupt the stratospheric polar vortex and, more often than not, bring cold weather to the UK. The Quasi-Biennial Oscillation (QBO), an oscillation of the equatorial winds in the stratosphere, remains in a westerly phase. The QBO influences winter conditions over Western Europe by modulating the strength of the stratospheric polar vortex and thereby the phase of the NAO at the surface. The westerly phase of the QBO tends to favour a stronger stratospheric polar vortex, particularly in early winter, leading to a higher likelihood of a positive phase of the NAO.

 

During December, the factors described above suggest an increased likelihood of positive NAO, which is consistently supported by predictions from the Met Office seasonal prediction system along with systems from other global forecast centres. The left-hand graph in figure T2 shows a clear shift towards milder conditions. This does not preclude temporary incursions of colder weather, but  the chance of a prolonged spell of cold weather taking hold in December is low compared to normal.Through the first half of the 3-month period, milder-than-average conditions are more likely than colder-than average. However later in the winter, particularly into February, several seasonal forecasting systems, including the Met Office system, are in good agreement in suggesting a shift towards more blocked weather patterns; these patterns increase the chance of cold northerly or easterly winds affecting the UK. Therefore, the right-hand graph of figure T2 does not tell the whole story and in late winter the probability of colder-than-average conditions is actually higher than normal. Thus we consider the greatest risk of cold weather impacts, such as snow, to be in late winter.

 

Temperature Summary

 

Summary Precipitation

 

 

For December and December-January-February as a whole above-average precipitation is more probable than below-average. The probability that UK-average precipitation for December-January-February will fall into the driest of our five categories is between 10% and 15% and the probability that it will fall into the wettest of our five categories is 25% (the 1981-2010 probability for each of these categories is 20%).

 

As discussed in the temperature section, the ongoing El Niño event, together with the westerly phase of the Quasi-Biennial Oscillation (QBO), increases the chance of a positive phase of the North Atlantic Oscillation (NAO) in early winter. At this time of year, the positive phase of the NAO is associated with above-average precipitation and an increased frequency of Atlantic depressions crossing the UK. During December, the Met Office seasonal prediction system, along with systems from other global forecast centres, supports an increased risk of above-average rainfall. The left-hand graph in figure P2 highlights a clear shift towards

above-average precipitation with a reduced probability of below-average precipitation and an increased probability of above-average precipitation compared to normal. Furthermore, the risk of spells of windy or even stormy weather is expected to be greater than usual for the time of year.

 

For the season as a whole (December-January-February) predictions are more uncertain. Through the first half of the period, wetter-than-average conditions are more likely than drier-than-average, given that the positive NAO phase is likely to prevail. Thereafter the uncertainty in precipitation increases, as this is dependent on the position of the blocked weather patterns which are more likely to develop later in the winter.

 

Precipitation Summary

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

December update

January to March

Summary Temperature

Predictions for UK-mean temperature for the whole of the period (January-February-March) are generally within the normal range of expected conditions. However in this instance, there are reasons to believe that this unexceptional outlook conceals an increased risk of a change from a milder start to colder conditions later on. These different phases tend to balance the probability of above- and below-average conditions in the overall 3-month average but there is a greater risk of a transition to cold weather impacts later in the period. Overall, the probability that the UK-average temperature for January-February-March will fall into the coldest of our five categories is between 20 and 25% and the probability that it will fall into the warmest of our five categories is around 20% (the 1981-2010 probability for each of  these categories is 20%). As stated above, the January-February-March statistics disguise a shift in probabilities as winter progresses

Temperature outlook

Summary Precipitation

For January-February-March both above- and below-average precipitation are equally probable. The probability that UK-average precipitation for January-February-March will fall into the driest of our five categories is around 20% and the probability that it will fall into the wettest of our five categories is also around 20% (the 1981-2010 probability for each of these categories is 20%)

Precipitation outlook

Edited by Summer Sun
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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

January update issued

February to April

Summary Temperature

For February predictions are that above-average temperatures are slightly more probable than below-average. The likelihood of a prolonged spell of cold weather is relatively low. Predictions for UK-average temperature for the whole of the period (February-March-April) indicate that below-average temperature is more probable than above-average. Overall, the probability that the UK-average temperature for February-March-April will fall into the coldest of our five categories is between 20 and 25% and the probability that it will fall into the warmest of our five categories is between 10 and 15% (the 1981-2010 probability for each of these categories is 20%).

A strong, mature El Niño event in the tropical Pacific Ocean continues, and will remain a strong and significant feature during this forecast period which will continue to have wide reaching global impacts. This El Niño is comparable in strength to the 1997-98 and 1982-83 events and ranks among the strongest on record. For the UK region, the primary effect is to increase the probability of a significant ridge of pressure across the Mid-Atlantic during this period. There is also a strong link between El Niño and an increased probability of a sudden stratospheric warming (SSW) event occurring. These events disrupt the stratospheric polar vortex and more often than not, bring cold weather to the UK.

These signals correspond to the negative phase of the North Atlantic Oscillation (NAO), which is associated with generally colder and drier-than-average conditions across the UK. Shorter-range forecasts already indicate imminent weakening of the polar vortex. The timing of an SSW event and impacts on the UK are uncertain; this could occur between early February and early March. The Madden Julian Oscillation (MJO) is the major fluctuation in tropical weather on weekly to monthly timescales. The MJO can be characterised as an eastward moving 'pulse' of cloud and rainfall near the equator that typically recurs every 30 to 60 days. The MJO is expected to reach a phase in early February which is conducive to a negative phase of the NAO in mid- to late-February.

Detailed Temperature outlook

Summary Precipitation

For both February and for February-March-April both above- and below-average precipitation are equally probable. The probability that UK-average precipitation for February-March-April will fall into the driest of our five categories is around 20% and the probability that it will fall into the wettest of our five categories is also around 20% (the 1981-2010 probability for each of these categories is 20%).

Predictions for February and the season as a whole (February-March-April) are uncertain. This is because the precipitation across the UK is dependent on the position of the expected developing ridge across the Mid-Atlantic. While there is an increased chance of this feature developing, uncertainty in its exact position and the resulting flow across the UK translates into uncertainty in the rainfall. Overall, the probability of above- and below-normal are considered to be equally balanced.

Precipitation Summary

 

Edited by Summer Sun
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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

February update issued

March to May

Summary Temperature

For March on average, near-normal temperatures are more likely than either well-above or well-below normal temperatures. This reflects an increased tendency for fluctuations between mild conditions and colder spells. The chance of a prolonged spell of cold weather appears relatively low, although there remains a risk of cold weather impacts in the shorter cold spells. Predictions for UK-mean temperature averaged over the period March-April-May are that above-average temperatures are more probable than below-average. Overall, the probability that the UK-average temperature for March-April-May will fall into the coldest of our five categories is between 10 and 15% and the probability that it will fall into the warmest of our five categories is between 25 and 30% (the 1981-2010 probability for each of these categories is 20%).

Full temperature outlook

Summary Precipitation

For March, there is an increase in the chance of above-average precipitation, and a decrease in the chance of below-average precipitation, compared to usual. Predictions for UK-mean precipitation for the 3-month period (March-April-May) are that above-average precipitation is slightly more probable than below-average. Overall, the probability that the UK-average precipitation for March-April-May will fall into the driest of our five categories is 20% and the probability that it will fall into the wettest of our five categories is around 25% (the 1981-2010 probability for each of these categories is 20%).

Full precipitation outlook

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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

March update issued

April to June

Summary Temperature

For April, near-average temperatures are most likely. For the period April-May-June above-average temperatures are more probable than below-average. Overall, the probability that the UK-average temperature for April-May-June will fall into the coldest of our five categories is around 15% and the probability that it will fall into the warmest of our five categories is around 30% (the 1981-2010 probability for each of these categories is 20%).

Full temperature outlook

Summary Precipitation

For April, and April-May-June as a whole, above-average precipitation is considered more probable than below-average. Overall, the probability of the UK-average precipitation for April-May-June falling into the driest of our five categories is between 15 and 20%. The probability of UK-average precipitation falling into our wettest category is around 25% (the 1981-2010 probability for each of these categories is 20%)

Full precipitation outlook

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

April update issued

May to July

Summary Temperature

For May, the probabilities of above-average and below-average temperatures are fairly well balanced, with above-average only slightly more likely. Likewise, for May-June-July above-average temperatures are slightly more probable than below-average temperatures. Overall, the probability that the UK-mean temperature for May-June-July will fall into the coldest of our five categories is around 15% and the probability that it will fall into the warmest of our five categories is between 20% and 25% (the 1981-2010 probability for each of these categories is 20%).

Full temperature outlook

Summary Precipitation

Predictions for UK precipitation show a slight increase in the probability of above-average rainfall for May. For May-June-July as a whole, the forecast for UK precipitation suggests that the chances of above- and below-average rainfall are fairly balanced. The probability that UK precipitation for May-June-July will fall into the driest of our five categories is between 20% and 25% and the probability that it will fall into the wettest of our five categories is 25% (the 1981-2010 probability for each of these categories is 20%).

Full precipitation outlook

 

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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

May update

June to August

Summary Temperature

For June, and for June-July-August as a whole, above-average temperatures are slightly more probable than below-average. The size of these shifts in probability are, however, moderate. Overall, the probability that the UK-mean temperature for June-July-August will fall into the coldest of our five categories is around 20% and the probability that it will fall into the warmest of our five categories is around 30% (the 1981-2010 probability for each of these categories is 20%). The right-hand graph in figure T2 shows a slight shift in probability towards above-average temperatures.

Full temperature outlook

Summary Precipitation

For June, above-average precipitation is slightly more probable than below-average. For June-July-August as a whole, the forecast for UK precipitation suggests that the chances of above- and below-average rainfall are fairly balanced (see right-hand graph in figure P2). As in the case of temperature, there are only relatively weak influences acting to modify the likelihood of above- and below-normal from what would normally be expected. The probability that UK precipitation for June-July-August will fall into the driest of our five categories is around 20% and the probability that it will fall into the wettest of our five categories is also around 20% (the 1981-2010 probability for each of these categories is 20%).

Full precipitation outlook

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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

July update

August to October

Summary Temperature

For August, near-average temperatures are more probable than either above- or below-average. For August-September-October as a whole, above average temperatures are slightly more probable than below-average. Overall, the probability that the UK-mean temperature for August-September-October will fall into the coldest of our five categories is 15% and the probability that it will fall into the warmest of our five categories is 25% (the 1981-2010 probability for each of these categories is 20%)

Full temperature outlook

Summary Precipitation

For August, above-average precipitation is considered slightly more probable than below-average. For August-SeptemberOctober as a whole, the forecast for UK precipitation suggests that the chances of above- and below-average rainfall are fairly balanced.  The probability that UK precipitation for August-September-October will fall into the driest of our five categories is between 15 and 20% and the probability that it will fall into the wettest of our five categories is around 20% (the 1981-2010 probability for each of these categories is 20%)

Full precipitation outlook

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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

August update

September to November

Summary Temperature

For September and September-October-November, above-average temperatures are more probable than below-average. Overall, the probability that the UK-mean temperature for September-October-November will fall into the coldest of our five categories is between 15% and 20% and the probability that it will fall into the warmest of our five categories is 30% (the 1981-2010 probability for each of these categories is 20%).

Full temperature outlook

Summary Precipitation

For September, the forecast for UK precipitation suggests that the chances of above- and below-average rainfall are fairly balanced. For September-October-November as a whole, above-average precipitation is considered slightly more probable than below-average. The probability that UK precipitation for September-October-November will fall into the driest of our five categories is between 15 and 20% and the probability that it will fall into the wettest of our five categories is around 25% (the 1981-2010 probability for each of these categories is 20%).

Full precipitation outlook

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

September update

October to December

Summary Temperature

For October, higher than average temperatures are more probable than lower than average values. For October November December there are equal chances of higher than average temperatures and lower than average temperatures. Overall, the probability that the UK mean temperature for October November December as a whole will fall into the coldest of our five categories is around 25% and the probability that it will fall into the warmest of our five categories is also around 25% (the 1981 2010 probability for each of these categories is 20%).

Full temperature outlook

Summary Precipitation

For October, the chance of seeing above average precipitation is greater than the chance of seeing below average precipitation. For the period October-November-December as a whole, there are equal chances of above average and below average precipitation. The probability that UK precipitation for October November December as a whole will fall into the driest of our five categories is 20% and the probability that it will fall into the wettest of our five categories is also 20% (the 1981 2010 probability for each of these categories is 20%).

Full precipitation outlook

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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

This is quite a bullish forecast from the Met Office going for colder than average conditions through November and into December with heights building to the NW. Not often you see them going for a colder period - reminds me a bit of 2010..

Surprised this is not receiving much comment, given November is only a month away now.

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Posted
  • Location: Tullynessle/Westhill
  • Weather Preferences: Cold and snowy or warm and dry
  • Location: Tullynessle/Westhill
11 hours ago, damianslaw said:

This is quite a bullish forecast from the Met Office going for colder than average conditions through November and into December with heights building to the NW. Not often you see them going for a colder period - reminds me a bit of 2010..

Surprised this is not receiving much comment, given November is only a month away now.

It's received a bit of comment over in the ENSO thread. I agree, surprisingly good, from a coldies point of view, forecast. It's all based om models though so lets hope it's right.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

At first reading the contingency planning forecast October-December seems at odds with their other seasonal outlooks, see link below

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

So not sure why there is a difference (slight) in emphasis bewteen the two outputs?

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Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll
34 minutes ago, johnholmes said:

At first reading the contingency planning forecast October-December seems at odds with their other seasonal outlooks, see link below

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

So not sure why there is a difference (slight) in emphasis bewteen the two outputs?

The images on the UKMO site were last updated on 12/9 .... the contingency forecast will have more up to date runs to look at. The difficulty of seeing a picture in 3 monthly blocks, published once a month, where the atmosphere is constantly changing and throwing some curve balls as it does.

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Posted
  • Location: Evesham, Worcs, Albion
  • Location: Evesham, Worcs, Albion
22 hours ago, johnholmes said:

At first reading the contingency planning forecast October-December seems at odds with their other seasonal outlooks, see link below

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

So not sure why there is a difference (slight) in emphasis bewteen the two outputs?

"Raw data are displayed for use by international meteorological centres. This does not constitute a seasonal forecast for a given location." 

The Contingency Planners takes GloSea4 output into account, but is based on human interpretation of that and much other data.   You should know that :p   

Also worth noting that the CP suggests an overall average O-N-D but with a warm Oct balanced by colder Nov/Dec.  

Its why journalists should never ever be allowed anywhere near GloSea4 output!

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  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

October update

November to January

Summary Temperature

For November-December-January, lower-than-average temperatures are more probable than higher-than-average values. Overall, the probability that the UK-mean temperature for November-December-January will fall into the coldest of our five categories is 30% and the probability that it will fall into the warmest of our five categories is 10% (the 1981-2010 probability for each of these categories is 20%)

Temperature

Summary precipitation

For the period November-December-January as a whole, the chances of below-average precipitation are higher than those of above-average values. The probability that UK precipitation for November-December-January will fall into the driest of our five categories is between 20 and 25% and the probability that it will fall into the wettest of our five categories is around 15% (the 1981-2010 probability for each of these categories is 20%)

Precipitation

Edited by Summer Sun
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