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January 2017: Earth's 3rd Warmest January on Record; Lake Oroville Water Levels Drop

By: Jeff Masters and Bob Henson 5:38 PM GMT on February 16, 2017

January 2017 was the planet's third warmest January since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Thursday. Along with NOAA, NASA also rated January 2017 as the third warmest January on record. The only warmer Januarys were 2016 (highest) and 2007 (second highest). Global ocean temperatures during January 2017 were the second warmest on record, and global land temperatures were the third warmest on record. Global satellite-measured temperatures in January 2017 for the lowest 8 km of the atmosphere were the sixth warmest in the 39-year record, according to the University of Alabama Huntsville (UAH).

It's remarkable that Earth saw its third warmest January on record without any help from El Niño, which works to raise global air temperatures by exporting heat from the oceans. Sea-surface temperatures in the Niño 3.4 region of the tropical Pacific rose into the cool side of the neutral range during January, although a La Niña Advisory was still in effect. In contrast, the warmest and second warmest Januarys (2007 and 2016) both occurred during an El Niño event.

Figure 1. Departure of temperature from average for January 2017, the 3rd warmest January for the globe since record keeping began in 1880. Three of the six continents had at least a top six warm January, with South America having its second warmest January since continental records began in 1910 (behind 2016.) Image credit: National Centers for Environmental Information (NCEI).

No billion-dollar weather disasters in January 2017
No billion-dollar weather-related disasters hit the Earth last month, according to the January 2017 Catastrophe Report from insurance broker Aon Benfield. The most destructive weather-related event during the month was Chile’s worst wildfires in modern history, which killed eleven people and cost at least $890 million. The deadliest weather-related disaster of January was the rainy season flooding in the southern African countries of Mozambique and Zimbabwe, which killed at least 179 people.

Figure 2. Smoke settles over Santiago, Chile on January 20, 2017. January fires in Chile cost the nation at least $890 million, and killed eleven people. Pudahuel Airport in western Santiago on January 20 hit 37.7°C (99.9°F), the hottest temperature ever recorded in the Santiago metropolitan area. Santiago Observatory (with records back to 1866) set its all-time heat record on January 25, 2017 with 37.4°C. Image credit: Martin Bernetti/AFP/Getty Images.

So Long, La Niña; Hello again, El Niño?
In its February monthly advisory, NOAA’s Climate Prediction Center (CPC) sounded the death knell for the 2016-17 La Niña. Sea surface temperatures (SSTs) in the benchmark Niño 3.4 region (in the equatorial Pacific) warmed to 0.3°C below average during early February; SSTs of 0.5°C or more below average in this region are required to be classified as weak La Niña conditions. Over the past week, SSTs have warmed rapidly in the Niño 3.4 region to more than 0.5°C above average but this surge may be temporary (Figure 3). We would need to see sustained warmth for many weeks at this level before crying, “El Niño is coming!” NOAA forecasters estimate an approximately 60% chance of neutral conditions lasting through the spring. For the September - November 2017 period, they predict a 12% chance of La Niña conditions, a 40% chance of neutral conditions, and a 48% chance of an El Niño. The latest Australian Bureau of Meteorology models are more aggressive about El Niño, showing development by this spring, and the latest May-June-July run of the UKMET model predicted a moderate El Niño by early summer. El Niño conditions tend to suppress Atlantic hurricane activity by bringing strong upper-level winds to the tropical Atlantic, creating high wind shear that tears storms apart.

Figure 3. Sea surface temperatures (SSTs) in the benchmark Niño 3.4 region (in the equatorial Pacific) have warmed above the 0.5°C above average threshold over the past week; SSTs of 0.5°C or more above average in this region are required to be classified as weak El Niño conditions. This recent surge in SSTs may be temporary; as Micheal Ventrice noted on Twitter today, there was a westerly wind burst over the past week that helped fuel this warming, but near-normal easterly trade winds have resumed. Image credit: Levi Cowan, tropicaltidbits.com.

Arctic sea ice falls to lowest January extent on record
Arctic sea ice extent during January 2017 was the lowest in the 39-year satellite record, beating the record set in January 2016, according to the National Snow and Ice Data Center (NSIDC). Very warm air invaded the Arctic in mid-January, part of a trend we’ve seen all winter. A drifting buoy located near the Pole, at about 87°N latitude, has recorded temperatures at or above freezing three times since November: once in November 2016, once in December 2016, and once on February 10. In a February 10 interview in the Washington Post, atmospheric physics expert Kent Moore of the University of Toronto noted that these types of anomalous warming events have been recorded since the 1950s, but only occurred once or twice a decade. Record arctic sea ice loss in recent years is allowing these events to occur more frequently. Moore said: “As that sea ice moves northward, there’s a huge reservoir of heat over the north Atlantic. As we lose the sea ice, it allows essentially this reservoir of warmth to move closer to the pole.”

Notable global heat and cold marks set for January 2017
Hottest temperature in the Northern Hemisphere: 41.5°C (106.7°F) at N'Djamena, Chad, 24 January
Coldest temperature in the Northern Hemisphere: -58.7°C (-73.7°F) at Summit, Greenland, 12 January
Hottest temperature in the Southern Hemisphere: 47.0°C (116.6°F) at Bourke Airport, Australia, 13 January
Coldest temperature in the Southern Hemisphere: -45.3°C (-49.5°F) at Dome A, Antarctica, 31 January
(Courtesy of Maximiliano Herrera.)

Major weather stations that set (not tied) new all-time heat or cold records in January 2017
Durres (Albania) min. -9.0°C, 8 January
Vlore (Albania) min. -9.4°C, 8 January
Dudince (Slovakia) min. -30.5°C, 8 January
Apia (Samoa) max. 35.2°C, 9 January
Santiago Airport (Chile) max. 37.7°C, 20 January
Isla de Maipo (Chile) max. 37.9°C, 20 January
Santiago Observatory (Chile) max. 37.4°C, 25 January
Rapel (Chile) max. 36.8°C, 25 January
Linares (Chile) max. 41.8°C, 26 January
Chillan (Chile) max. 41.5°C, 26 January
Quinchamali (Chile) max. 43.0°C, 26 January
Los Angeles (Chile) max. 42.2°C, 26 January 
Parral (Chile) max. 40.8°C, 26 January
Concepcion Airport (Chile) max. 34.1°C, 26 January
Cauquenes (Chile) max. 45.0°C, 26 January;  (new national record high for Chile)
Robinson Crusoe Island-Juan Fernandez (Chile) max. 28.8°C, 26 January
Trelew (Argentina) max. 42.2°C, 27 January
Puerto Madryn (Argentina) max. 43.4°C, 27 January

(Courtesy of Maximiliano Herrera.)

One all-time national heat record set in January 2017
One nation set an all-time record for hottest temperature in recorded history in 2017: Chile (see above). Most nations do not maintain official databases of extreme temperature records, so the national temperature records reported here are in many cases not official. I use as my source for international weather records researcher Maximiliano Herrera, one of the world's top climatologists, who maintains a comprehensive list of extreme temperature records for every nation in the world on his website. If you reproduce this list of extremes, please cite Maximiliano Herrera as the primary source of the weather records.

Figure 4. Departures from average temperature (left) and precipitation (right) for the contiguous United States in January 2017. Image credit: NOAA/NCEI.

U.S. in January: Warmer and wetter than average
Last month the contiguous U.S. saw its 18th warmest and 9th wettest January in 123 years of record-keeping, as reported last week by NOAA/NCEI. Warmer-than-average temperatures covered nearly all of the nation east of the Rockies during January as a whole, although there was considerable variability, including a sharp cold spell in the second week of the month. Most states along a swath from Texas to Maine saw a top-ten-warmest January, although no state set a record. Only two states (Washington and Montana) experienced precipitation well below average, while ten states from California to Georgia saw the month place among their top ten wettest Januarys.

Figure 5. Predicted 7-day rainfall amounts in northern California beginning on Thursday, February 16. Image credit: NWS Sacramento.

Water levels in Lake Oroville continue to drop even as rains hit California
The water level at the troubled Lake Oroville reservoir in California continued to drop on Thursday morning, even as rainy weather moved into the region. The lake level fell by nearly 5 feet in the 12-hour period ending at 6 a.m. PST Thursday, to 869 feet, about 30 feet below its capacity. According to reports from the Sacramento Bee, state water officials continued to release 100,000 cubic feet per second (cfs) of water from the lake’s main spillway, and damage to that spillway has not worsened. Water was flowing into the lake at 34,000 cfs Thursday morning. About one half inch of rain is expected in the area on Thursday, with another half-inch on Friday (the rains will be much heavier in Southern California, see embedded tweet below.) Dam operators are expecting inflows of up to 50,000 cfs through Friday, so the lake level will continue to fall as long as the main spillway continues to release 100,000 cfs of water. During last week’s heavy rains that caused the reservoir to overflow, inflow peaked at 197,000 cfs. On Sunday, Monday and Tuesday, another very wet Pacific storm system is expected to dump at least three inches of rain on the area. This is about the same amount of rain that fell during the storm that caused inflow rates to reach 197,000 cfs last week. If the upstream rainfall amounts also end up being similar in magnitude to last week’s storm, we can expect Lake Oroville to begin rising by Monday. However, assuming that dam operators can continuously release 100,000 cfs of water from the reservoir during the coming week, it appears unlikely that the lake will reach 900 feet and force usage of the emergency spillway again.

Climatesignals.org has an excellent summary of how climate change may have contributed to the Lake Oroville Dam emergency.

We'll have a new post on Friday.

Jeff Masters and Bob Henson

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The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.