Copernicus – April 2023 tied with 2018 to be the 4th warmest April recorded.
Copernicus
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This year is shaping up to be one of top four warmest years on record – and has a modest chance of being the warmest on record.
Exceptionally warm conditions are being driven by the end of a persistent triple-dip La Niña and a rapid transition into warmer El Niño conditions.
Taking the first three months of the year, global surface temperatures so far are tied as the fourth warmest on record, after 2016, 2020 and 2017.
March 2023 was the second warmest since records began in the mid-1800s, with record warm temperatures in parts of central Asia, coastal China, and Japan, as well as South America.
Based on the year-to-date and the current El Niño forecast, Carbon Brief estimates that 2023 is very likely to end up between the warmest year on record and the sixth warmest, with a best estimate of fourth warmest. So early in the year, it is difficult to precisely predict where annual temperatures will end up.
Arctic sea ice extent is currently on the low end of its historical range, while Antarctic sea ice set new all-time low records in the first two months of 2023, with an all-time low summer minimum for the Southern Hemisphere in February 2023.
El Niño and La Niña events – collectively referred to as the El Niño Southern Oscillation, or ENSO – are the main driver of year-to-year variation in global surface temperature on top of the long-term warming trend. ENSO events are characterised by fluctuations in temperature between the ocean and atmosphere in the tropical Pacific, which help to make some years warmer and some cooler.
Nearly all forecasts for El Niño/La Niña suggest that El Niño conditions will develop by early summer in 2023, with a number of models projecting strong El Niño conditions (if not quite as strong as the super El Niño events experienced in 1998 and 2016).
Predicting global temperature in 2023
The first three months of 2023 can give some sense of what to expect for the entire year.
By looking at the relationship between the first three months and the annual temperatures for every year since 1970 – as well as ENSO conditions for the first three months of the year and the projected development of El Nino conditions for the remaining nine months – Carbon Brief has created a projection of what the final global average temperature for 2023 will likely turn out to be.
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El Niño is likely to take over soon — and odds are it will be sticking around for a long time, national forecasters said in an update Thursday.
While the Northern Hemisphere is still under “ENSO-neutral” conditions — meaning we are neither in an El Niño nor La Niña — that could change at any time. The National Oceanic and Atmospheric Administration’s Climate Prediction Center said there is about an 80% chance the transition to El Niño takes place between May and July.
Once it takes hold, El Niño is likely to strengthen into the fall and winter, when it normally peaks. The odds of it lasting until February of 2024 are upwards of 90%, the Climate Prediction Center said.
An El Niño winter would be a switch from what what we’ve seen the last three years, with back to back to back La Niña seasons.
El Niño typically brings cold, wet winter to the Southern U.S. A strong El Niño in particular is associated with lots of rain for the Southwest and California — though California already saw a cold, wet winter this year even without El Niño in control.
On the other hand, El Niño usually means a warm, dry winter for the Pacific Northwest, Ohio Valley, northern Rockies and parts of the Midwest. Hawaii also often sees below-average rain during an El Niño fall, winter and spring season.
While El Niño can strengthen hurricane season in the central and eastern Pacific, it tends to contribute to weaker hurricanes forming in the Atlantic basin.
Even a strong El Niño isn’t a guarantee those exact scenarios will play out, NOAA warns.
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Little extra - Extreme weather
- Record early season heat wave envelopes Pacific Northwest
Nearly 11 million people in the Pacific Northwest were under heat advisories — as forecasters warned cities including Seattle and Portland could see more temperature records set Monday from the intense heat wave.
The big picture: The early season heat wave that began Friday has seen temperature records broken from Washington and Oregon to Alberta, where Canadian firefighters have been tackling dozens of wildfires for days, from British Columbia and up to northern Canada.
Meanwhile, beyond the Pacific Northwest, Yosemite National Park announced three campgrounds would temporarily close Monday due to forecast flooding from the melting of the Sierra Nevada's historic snowpack.
- "The combination of extended hot weather and abundant snow means the Merced River may remain above flood stage for some time," the Yosemite National Park Service tweeted.
Threat level: "Above-normal temperatures are forecast to persist along the West Coast ... while extending across the Intermountain West and into the Rockies early this week," the National Weather Service warned Monday.
- "For many locations, daytime temperatures will reach 10-20 degrees above normal on both Monday and Tuesday.
- "While a weak area of low pressure in the upper levels of the atmosphere may provide some relief and an increasing chance for showers and thunderstorms, high temperatures may once again exceed their daily records for parts of the Pacific Northwest, including the Seattle and Portland metro regions, on Monday."
State of play: The National Weather Service reported temperature records in several cities in Washington and Oregon had either been set or tied over the weekend, according to preliminary data.
- The Seattle region saw daily temperature records set or tied in the same four cities for two consecutive days. These included Quillayute — which reached 90°F on Saturday, eclipsing the previous record for May 13 set in 1975 by 10 degrees. On Sunday, the data indicates that it tied its monthly record when it hit 92°F, per the NWS.
- Portland recorded its hottest ever daily temperature for May 13 of 93°F on Saturday and set a record temperature for May 14 of 92°F Sunday, according to the preliminary data.
Of note: Preliminary data indicates the tiny community of Arviat, Nunavut, on the western shore of Hudson Bay in northeastern Canada, saw its monthly heat record smashed on Saturday by nearly 7°C (44.6°F), meteorologist Scott Duncan tweeted.
Context: Numerous studies show climate change is leading to more intense heat waves that are more frequent and longer lasting.
https://www.axios.com/2023/05/15/pac...canada-records