Climate

Table of major mid-winter SSWs 1958-2020

The date of the major warming is calculated for each reanalysis product using daily-mean zonal-mean zonal winds at 60N and 10 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar, where the winds must return to westerly for 20 consecutive days between events, and for at least 10 days prior to April 30, following Charlton and Polvani (2007).
The El NiñoEl Niño El Niño 'The Boy' is the warm phase of the El Niño–Southern Oscillation and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific-Southern Oscillation (ENSOENSO El Niño–Southern Oscillation is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña.) phase (E = El Niño, L = La NiñaLa Niña La Niña is an oceanic and atmospheric phenomenon that is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation climate pattern. The name La Niña originates from Spanish for "the girl", by analogy to El Niño, meaning "the boy". In the past, it was also called an anti-El Niño[1] and El Viejo, meaning "the old man.", N = Neutral) is defined following the convention of the NOAA NCEP Climate Prediction Center, which is based on the DJFDJF Meteorological Winter comprising the months of December, January & February Oceanic Niño Index (ONIONI The Oceanic Niño Index (ONI) is NOAA's primary index for tracking the ocean part of ENSO, the El Niño-Southern Oscillation climate pattern.) using ERSSTv5 data with a +/-0.5C threshold.
The Quasi-Biennial Oscillation (QBOQBO The quasi-biennial oscillation (QBO) is a quasiperiodic oscillation of the equatorial zonal wind between easterlies and westerlies in the tropical stratosphere with a mean period of 28 to 29 months. The alternating wind regimes develop at the top of the lower stratosphere and propagate downwards at about 1 km per month until they are dissipated at the tropical tropopause. Downward motion of the easterlies is usually more irregular than that of the westerlies. The amplitude of the easterly phase is about twice as strong as that of the westerly phase. At the top of the vertical QBO domain, easterlies dominate, while at the bottom, westerlies are more likely to be found.) phase (E = easterly, W = westerly) is defined using the DJF-mean equatorial QBO time series at 50 hPa from the Freie Universität Berlin.
The frequency of SSWsSSW A sudden stratospheric warming (SSW) is an event in which polar stratospheric temperatures rise by as much as 50 °C in the course of a few days. The warming is preceded by a slowing then reversal of the westerly winds in the stratospheric polar vortex. SSWs occur about six times per decade in the northern hemisphere, and about once every 20-30 years in the southern hemisphere. for each reanalysis is calculated for the 1958-2019 period for NCEPNCEP The United States National Centers for Environmental Prediction (NCEP) delivers national and global weather, water, climate and space weather guidance, forecasts, warnings and analyses to its Partners and External User Communities.-NCARNCAR The US National Center for Atmospheric Research is a US federally funded research and development center (FFRDC) managed by the nonprofit University Corporation for Atmospheric Research (UCAR) and funded by the National Science Foundation (NSF). and JRAJRA The Japan Meteorological Agency (JMA) is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation and research into natural phenomena in the fields of meteorology, hydrology, seismology and volcanology, among other related scientific fields. Its headquarters is located in Minato, Tokyo.-55; for the 1958-2002 period for ERAERA ERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera).-40; for the 1979-2019 period for ERA-interim; and for the 1980-2019 period for MERRA-2.

Event NameNCEP-NCARERA40ERA-InterimJRA-55MERRA2ENSOQBO 50mb
JAN 195830-Jan-5831-Jan-5830-Jan-58EW
NOV 195830-Nov-58********EE
JAN 196016-Jan-6017-Jan-6017-Jan-60NW
JAN 1963****28-Jan-6330-Jan-63NE
MAR 196523-Mar-65********LW
DEC 19658-Dec-6516-Dec-6518-Dec-65EE
FEB 196624-Feb-6623-Feb-6623-Feb-66EE
JAN 1968****7-Jan-687-Jan-68LW
NOV 196827-Nov-6828-Nov-6829-Nov-68EE
MAR 196913-Mar-6913-Mar-69****EE
JAN 19702-Jan-702-Jan-702-Jan-70EW
JAN 197117-Jan-7118-Jan-7118-Jan-71LE
MAR 197120-Mar-7120-Mar-7120-Mar-71LE
JAN 19732-Feb-7331-Jan-7331-Jan-73EE
JAN 1977****9-Jan-779-Jan-77EE
FEB 197922-Feb-7922-Feb-7922-Feb-7922-Feb-79NW
FEB 198029-Feb-8029-Feb-8029-Feb-8029-Feb-8029-Feb-80EE
FEB 1981************6-Feb-81****NW
MAR 1981****4-Mar-814-Mar-814-Mar-81****NW
DEC 19814-Dec-814-Dec-814-Dec-814-Dec-814-Dec-81NE
FEB 198424-Feb-8424-Feb-8424-Feb-8424-Feb-8424-Feb-84LW
JAN 19852-Jan-851-Jan-851-Jan-851-Jan-851-Jan-85LE
JAN 198723-Jan-8723-Jan-8723-Jan-8723-Jan-8723-Jan-87EW
DEC 19878-Dec-878-Dec-878-Dec-878-Dec-878-Dec-87EW
MAR 198814-Mar-8814-Mar-8814-Mar-8814-Mar-8814-Mar-88EW
FEB 198922-Feb-8921-Feb-8921-Feb-8921-Feb-8921-Feb-89LW
DEC 199815-Dec-9815-Dec-9815-Dec-9815-Dec-9815-Dec-98LE
FEB 199925-Feb-9926-Feb-9926-Feb-9926-Feb-9926-Feb-99LE
MAR 200020-Mar-0020-Mar-0020-Mar-0020-Mar-0020-Mar-00LW
FEB 200111-Feb-0111-Feb-0111-Feb-0111-Feb-0111-Feb-01LW
DEC 20012-Jan-0231-Dec-0130-Dec-0131-Dec-0130-Dec-01NE
FEB 2002****18-Feb-02********17-Feb-02NE
JAN 200318-Jan-0318-Jan-0318-Jan-0318-Jan-03EW
JAN 20047-Jan-045-Jan-045-Jan-045-Jan-04NE
JAN 200621-Jan-0621-Jan-0621-Jan-0621-Jan-06LE
FEB 200724-Feb-0724-Feb-0724-Feb-0724-Feb-07EW
FEB 200822-Feb-0822-Feb-0822-Feb-0822-Feb-08LE
JAN 200924-Jan-0924-Jan-0924-Jan-0924-Jan-09LW
FEB 20109-Feb-109-Feb-109-Feb-109-Feb-10EW
MAR 201024-Mar-1024-Mar-1024-Mar-1024-Mar-10EW
JAN 20137-Jan-136-Jan-137-Jan-136-Jan-13NE
FEB 201812-Feb-1812-Feb-1812-Feb-1812-Feb-18LW
JAN 20192-Jan-192-Jan-192-Jan-192-Jan-19EE
Total Events3729263925
Frequency: Events/Decade6.06.46.36.36.3

I can’t see what the big fuss is about the chances of a change to very cold following an SSWSSW A sudden stratospheric warming (SSW) is an event in which polar stratospheric temperatures rise by as much as 50 °C in the course of a few days. The warming is preceded by a slowing then reversal of the westerly winds in the stratospheric polar vortex. SSWs occur about six times per decade in the northern hemisphere, and about once every 20-30 years in the southern hemisphere. event. More often or not CETCET Central England Temperature in the following weeks is completely unaffected. Here are some examples of SSW events in recent years.

22 Feb 1979
23 Jan 1987
15 Dec 1998
7 Jan 2013
9 Feb 2010
2 Jan 2019
SSW

Table of major mid-winter SSWs 1958-2020 Read More »

Summer 2022 [JJA] Heathrow – Coningsby comparison

I have been collecting hourly SYNOPSYNOP SYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. SYNOP reports are typically mad hourly and consist of groups of numbers (and slashes where data is not available) describing general weather information, such as the temperature, barometric pressure and visibility at a weather station. observations for many years now from across the world. I must have many tens of millions of observations dating right back to 1973. So I thought it might be interesting to look at some of these hourly observations in more detail.
I have always thought a 24 hour moving average of temperature for somewhere, gives a much better view of the temperature data than just the daily extremes. So the comparison graph between summer 24 hour average temperatures at Heathrow airport and Coningsby for 2022, shows that although Coningsby is now infamous as being the warmest place in the UKUK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland., with a maximum temperature of 40.3°C, it’s not when you calculate a 24 hour average. Furthermore. analysis of the number of hours above the UKMOUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy heatwave threshold at Heathrow of 133 hours, far surpasses that at Coningsby of 97 hours, even though the threshold at Heathrow is 28°C and only 27°C at Coningsby. So, not unsurprisingly, I can safely conclude that Heathrow was still the hottest spot in the UK despite what happened on the 19th of July.

Climate, Temperature

Summer 2022 [JJA] Heathrow – Coningsby comparison Read More »

Latest 12 month UK Climate averages

Mean temperatures in the UKUK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. in the 12 months to the end of January have fallen back a little and are now just a shade below the 10°C level. Twelve month UK rainfall totals continue to bounce back (98% of the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.), and are now over 1100 mm, up from the lows of below 1000 mm that were seen in last years the dry spell. UK 12 month sunshine totals continue well above the one standard deviation level (111% of the LTA), and above 1500 hours for the fourth consecutive month.

The climate of the UK is considerably warmer, slightly wetter and much sunnier than it was back in 1993.

Climate, Precipitation, Sunshine, Temperature

Latest 12 month UK Climate averages Read More »

January 2023 – Weather Summary

Temperatures were close to average in the north of Scotland during January, but it was a little duller than average (84%), with precipitation close to average (96%). I’m not at all convinced that the AWSAWS Automatic Weather Station rain gauges in our part of the Highlands picked up and melted all the snow they collected during the snowy spell in the third week though.

Climate, January

January 2023 – Weather Summary Read More »

2022 not the warmest 12 months on record

If you spend some time grubbing around in the UKUK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. gridded temperature series from the UKMOUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy that extends back to the year 1884 as I do, you might find that the highest mean temperature for a 12 month period didn’t actually occur in the year 2022, but the 12 month period that ended in April 2007. The mean temperature of 10.41°C was considerably higher than that of 10.03°C for 2022 that has been bandied about so much in recents days by the media.
There’s no reason to think that the UKMO weren’t aware of this fact, but they obviously kept shtum about it, not wanting to detract from making an even bigger splash with a headline “Warmest year on record” or the climate crisis version of it “Hottest year ever!“.

Global Temperatures, Temperature, UKMO, Warm

2022 not the warmest 12 months on record Read More »

Latest 12 Month UK climate averages

  • Temperature across the UKUK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland., in the gridded data series from the UKMOUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy over the last 12 months have peaked, and fell back a little in December, without achieving the dizzy heights of 2007.
  • Rainfall has made a hesitant recovery after the dry winter and spring of 2022.
  • Average 12 month sunshine across the UK is still nudging upwards.
Precipitation, Sunshine, Temperature

Latest 12 Month UK climate averages Read More »

The Climate of Northern Scotland since 2000

Dear Diary,
I thought that I would take a quick look at what the climate has been doing since 2000 closer to home by means of 12 month moving averages of the gridded climate data for the North of Scotland and which I download from the Met OfficeUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy. Mean temperatures have edged fractionally warmer in the last 20 years, whilst annual precipitation has slightly decreased by 6mm per decade, sunshine has increased by 15 hours per decade. Nothing for Greta ThunbergGreta Thunberg Greta Tintin Eleonora Ernman Thunberg (born 3 January 2003) is a Swedish environmental activist who is known for challenging world leaders to take immediate action for climate change mitigation to get overly worked up about there then, but linear trends can be deceptive though, and I really should have used a thirty, and not a twenty year period, but what the hell, no one is reading this anyway.

Climate, Precipitation, Sunshine, Temperature

The Climate of Northern Scotland since 2000 Read More »

Mild November in Iceland

Undoubtedly the last couple of weeks in November have been very mild across Iceland, but don’t forget the cold weather back in October that brought the red warning for heavy snow from the IMOIMO Icelandic Meteorological Office (Icelandic: Veðurstofa Íslands) is Iceland's national weather service and as such a government agency under the Ministry of Environment and Natural Resources. It is also active in volcano monitoring, volcano seismology, and together with other institutions, responsible for civil protection in Iceland. This is climate in action, some weeks are warmer than average and some are colder. I reckon the 7 to 8 degrees are the result of foehnFoehn A foehn, is a type of dry, relatively warm, downslope wind that occurs in the lee (downwind side) of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes (see orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. winds at stations in the north of the island like we saw in Snowdonia in the last week. I would like to have produced a thermograph with anomalies for Reykjavik but they don’t publish daily extremes so this will have to do a town on the south coast.

Climate, Iceland, IMO, Temperature

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