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The National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) has been providing national, regional, and local climate services for more than 20 years. The NWS climate services building blocks consist of service provision infrastructure, partnership and outreach, discovery of user needs and requirements, and service delivery at national, regional, local, and tribal levels. To improve services, the NWS climate services program accelerated user engagement through customer surveys, workshops, and collaborations. Since 2002, the annual Climate Prediction Applications Science Workshop has developed a community of climate information producers and users through sharing of climate science applications, decision support tools, and effective communication practices. Although NWS had been producing operational climate monitoring and prediction products for several decades, the Weather Research and Forecasting Innovation Act of 2017 (U.S. Public Law 115-25) specifically mandated that NWS deliver services at subseasonal to seasonal time scales, including periods from two weeks to two years. Looking ahead, both the Department of Commerce (DOC) and NOAA have included climate services in their new 2022-26 strategic plans, including DOC's goal to address the climate crisis through mitigation, adaptation, and resilience efforts and NOAA's initiatives to build a Climate Ready Nation (CRN). The NWS Climate Services Program supports these strategic goals and CRN initiatives through integrating climate information into Impact-based Decision Support Services, the most critical element for implementation of the NWS strategy for a Weather-Ready Nation. This includes application of state-of-the-art climate monitoring and prediction products to the most societally relevant impacts while empowering regional and local climate delivery of enhanced services. KEYWORDS: Climate; Climate records; Climate services; Decision making; History; Societal impacts, 1. History of the NWS regional and local climate services The year 2023 marked the twentieth anniversary of the regional and local climate services infrastructure established in the National Oceanic [...]

Record low Bering Sea sea ice in 2018 had profound regional impacts. According to climate models, human-caused warming was an overwhelmingly likely contributor, and such low levels will likely be [...]

Earth System Observations. The Gulf of Alaska (GOA) and Bering Sea have been anomalously warm for several years with the warmth peaking in 2016. As a consequence of the high [...]

Snowstorms cause substantial disruption in the eastern United States and Canada each winter. While reductions in annual snowfall are projected over most of this region due to anthropogenic global warming, daily snowfall extremes that have the greatest impact may not decrease in the same manner. We examine changes to two extreme snowfall metrics: the 95th percentile of daily snowfall (SF95, cm) and the number of events during which 10% of the mean annual snowfall is exceeded during a single day (TC10, events yr−1). We explore changes to these metrics in two ensembles of the fifth‐generation Canadian Regional Climate Model, including four 0.22° (≈25 km) simulations driven by different coupled general circulation models as well as the higher‐resolution (0.11°, ≈12 km) ClimEx ensemble, driven by 50 members of a large initial‐condition ensemble of one global model. We find that while mean annual snowfall is projected to decrease over our domain, SF95 is projected to remain relatively constant, suggesting that the most extreme daily snowfalls currently observed are likely to occur even in a warmer future climate. The region of the largest TC10 values exhibits a northward shift, with a larger percentage of annual snowfall occurring during a few large events along the U.S.‐Canada border. These projected changes to the nature of snowfall events may have important socioeconomic consequences in this densely populated region of North America. Plain Language Summary: Snowstorms affect the highly populated regions of the northeastern United States and southeastern Canada every winter, disrupting ground and air travel and resulting in substantial socioeconomic impacts. Understanding how climate change may impact snowstorms is necessary for this region to prepare for the future. We explore how snowstorms in these regions may change in a future, warmer world using two sets of climate model simulations. We find that yearly total snowfall is likely to decrease over most of this region, with the largest declines to the south and smaller declines farther north. Despite these decreases, we find that the snowfall amounts that currently occur during the largest snowstorms are still likely to occur even in a much warmer future climate. Finally, we examine snowstorms that produce a large percentage of the annual snowfall during a single event. We find that the region where these big snowstorms relative to the yearly snowfall occur most often will shift northward in the future. In summary, while yearly snowfall is likely to decrease nearly everywhere in eastern North America, significant snowstorms will continue to occur, and some regions will see more of their yearly snowfall during a few large events. Key Points: Mean annual snowfall is projected to decrease across most of eastern North America as the Earth continues to warmThe most intense high‐impact snowfall events currently observed will continue to occur in a warmer climateA larger percentage of yearly snowfall is likely to fall during a few large events near the Canada‐United States border [ABSTRACT FROM AUTHOR]

Some of the largest climatic changes in the Arctic have been observed in Alaska and the surrounding marginal seas. Near-surface air temperature (T2m), precipitation (P), snowfall, and sea ice changes have been previously documented, often in disparate studies. Here, we provide an updated, long-term trend analysis (1957-2021; n 5 65 years) of such parameters in ERA5, NOAA U.S. Climate Gridded Dataset (NClimGrid), NOAA National Centers for Environmental Information (NCEI) Alaska climate division, and composite sea ice products preceding the upcoming Fifth National Climate Assessment (NCA5) and other near-future climate reports. In the past half century, annual T2m has broadly increased across Alaska, and during winter, spring, and autumn on the North Slope and North Panhandle (T2m. 0.508C decade21). Precipitation has also increased across climate divisions and appears strongly interrelated with temperature-sea ice feedbacks on theNorth Slope, specifically with increased (decreased) open water (sea ice extent). Snowfall equivalent (SFE) has decreased in autumn and spring, perhaps aligned with a regime transition of snow to rain, while winter SFE has broadly increased across the state. Sea ice decline and melt-season lengthening also have a pronounced signal around Alaska, with the largest trends in these parameters found in the Beaufort Sea. Alaska's climatic changes are also placed in context against regional and contiguous U.S. air temperature trends and show; 50% greater warming in Alaska relative to the lower-48 states. Alaska T2m increases also exceed those of any contiguous U.S. subregion, positioning Alaska at the forefront of U.S. climate warming. [ABSTRACT FROM AUTHOR]

The National Climatic Data Center and numerous other sources list the 15.20-in. (386 mm) rainfall observed at the Angoon, Alaska, cooperative weather station on 12 October 1982 as the state record for a single calendar-day precipitation amount. However, a close inspection of the precipitation data recorded during 1982 in Angoon reveals a pattern of suspect values, calling into question the validity of the data collected during this time period. Our analysis shows that errors may be present in the Angoon precipitation record, and therefore consideration should be given to removing those values from the official climate database. This study evaluates Angoon precipitation observations over a 12-month period starting in February 1982 using two objective analytical techniques (statistical and climatological) and a 2012 interview of the Angoon cooperative station observer during the time period in question. If the Angoon precipitation values are deemed erroneous, then the 12 October 1982 observation will no longer hold the distinction as the single largest precipitation event. The second place event is a 15.05 in. (382 mm) observation measured in Seward, Alaska, on 10 October 1986., The validity of the Alaska record for single-day maximum precipitation is studied using two objective analytical techniques. The climate record of Alaska and the rest of the United States is [...]

Weather and sea ice forecasts provided in support of the U.S. Navy's Ice Exercise winter 2020 campaign in the Beaufort Sea noted frequent storms in the absence of the climatological Beaufort High which coincided with anomalous eastward drift of the region's ice cover. To place the 2020 Beaufort‐Chukchi regional atmospheric conditions in historical context, we evaluated winter low sea‐level pressure (SLP) extremes and storm characteristics in the region over the 1948–2020 period. March 2020 SLP in the Beaufort‐Chukchi region was the lowest of the modern reanalysis era (1009.07 hPa) with record counts of passing storms and days with SLP at least two standard deviations below the climatological mean. The Beaufort High collapse in winter 2020 continued a recent pattern of Beaufort High collapses dating back to 2010. Unlike other recent collapses, such as 2017, most of the late‐winter 2020 cyclones originated locally over the western Arctic Ocean. Plain Language Summary: Unusually stormy winter weather occurred in the southern Beaufort Sea during February and March 2020, affecting the U.S. Navy's Ice Exercise (ICEX) operations. Instead of the typical Beaufort High pressure pattern and associated easterly winds, frequent and at times intense storms moved across the Chukchi and Beaufort Seas, ushering westerly winds and eastward drift of sea ice and the ICEX camp. To quantify how unusual these weather conditions were, we evaluated storm activity from 1948 to 2020. March 2020 set a low pressure record for the month, in part because a record‐number of intense storms that moved across the area. This storminess was supported by an unusually strong atmospheric circulation pattern over the Arctic Ocean that aided repetitive storm passage. Since 2010, the late‐winter Beaufort High has been less common amidst more frequent storm activity, and three of the lowest four March mean sea‐level pressure values on record have occurred during the last 4 years. This change in weather conditions has broad implications for the Arctic environment. Key Points: March sea‐level pressure (SLP) in 2020 was the lowest since 1948 over the Beaufort and Chukchi SeasFrequent and intense storms contributed to anomalous eastward sea ice motion in the regionMarch 2020 continued a recent trend of Beaufort High collapse events as three of the four lowest March SLPs have occurred since 2017 [ABSTRACT FROM AUTHOR]

Alaska has experienced some of the strongest warming rates in the Northern Hemisphere since the mid-20th century. The winter-season warming is especially strong: approximately 4.1 °C since 1950. The atmospheric circulation contributes to interannual variability of Alaska's temperatures through advection and thereby contributes to temperature trends over decadal to multidecadal timescales. In this study, we quantify the contribution of the atmospheric circulation to Alaska's warming by using an analog methodology to identify years with sea level pressure patterns most closely resembling the pressure pattern of each year between 1950 and 2017. The analogs enable a dynamical adjustment of temperature anomalies by removing the contribution of the atmospheric circulation. The dynamical adjustment explains approximately half the variance of Alaska's statewide temperature in winter, and smaller fractions in the other seasons. The unexplained variance, termed the "excess warmth," shows a systematic increase from 1950 to 2017. The trends in the excess warmth correspond to a warming of 2.1 °C in winter and spring, 1.3 °C in summer, and 0.5 °C in autumn, which are consistent with the trends simulated by global climate models run with historical and projected greenhouse gas concentrations for the same period. The excess warmth accounts for 51% of the Alaska's winter warming and 75% of Alaska's annual mean warming over the 1950–2017 time period. [ABSTRACT FROM AUTHOR]

The article focuses on a study which aims to examine the impact of the high latitude marine heat wave on Alaska in 2016. Topics being presented include observed marine warmth, impacts on the marine ecosystem, and an attribution analysis using CMIP5 models, which suggest human-induced climate change has greatly increased the risk of such anomalies.

On 27 August 1904, seismic stations from around the globe recorded an M>7 earthquake originating from central Alaska. Very little was known about this earthquake. One felt report from Rampart, Alaska, had been attributed to the notes of Harry Fielding Reid, yet its original source was unknown. Here, we present five felt reports for the 1904 earthquake that show evidence of felt shaking across most of central Alaska. Using the 1904 arrival-time data, we estimate an epicentral location near Lake Minchumina at the northeastern extent of the Iditarod-Nixon fault. Our preferred fault for the 1904 earthquake is the right-lateral Iditarod-Nixon fault, which, though relatively seismically quiet, generated an M 6.2 earthquake in 1935. Paleoseismic investigations are needed to search for evidence of fault activity, including the 1904 earthquake rupture, in the tectonically complex region of the 1904 earthquake. [ABSTRACT FROM AUTHOR]