WEEKLY CLIMATE NEWS

10-14 May 2021

ITEMS OF INTEREST

• The Three Ice Saints weather legend continues -- A long-standing legend exists across sections of northern Europe and areas of the Northeastern States and Upper Midwest that a short spell of unseasonably cold air spreads across these regions between the 10th and 15th of May, at about the time of the feast days for the "three Ice Saints." The dates for these Ice Saints are 11 May for St. Mamertus (or, in some countries, St. Boniface of Tarsus), the 12th for St. Pancras, and the 13th for St. Servatius. The Midwest and Northeast had a spell of cold weather with subfreezing temperatures at the end of last week and over this past weekend, just before the Three Ice Saints days.
• Worldwide GLOBE at Night 2021 Campaign for May is underway -- The fifth in a series of GLOBE at Night citizen-science campaigns for the calendar year 2021 will continue through Tuesday, 11 May. GLOBE at Night is a worldwide, hands-on science and education program designed to encourage citizen-scientists worldwide to record the brightness of their night sky by matching the appearance of constellations with the seven magnitude/star charts of progressively fainter stars. These constellations are Bootes in the Northern Hemisphere, along with Crux in the Southern Hemisphere. Activity guides are also available. The GLOBE at night program is intended to raise public awareness of the impact of light pollution. The sixth series in the 2021 GLOBE campaign is scheduled for 1-10 June 2021. [GLOBE at Night]
• Hurricane season to begin in the eastern North Pacific -- The official 2021 hurricane season in the eastern North Pacific Ocean basin begins this Saturday, 15 May 2021. The hurricane season in the central North Pacific basin and the North Atlantic basin, including the Caribbean Sea and the Gulf of Mexico will begin in two weeks on 1 June. The official hurricane seasons in all of these three basins end on 30 November 2021.
• Hurricane preparedness activities planned for this week --
• Hurricane Awareness Week -- NOAA has declared this week of 9-15 May 2021 to be Hurricane Awareness Week 2021 across the nation. ?? At least a dozen states along the Gulf Coast and the Atlantic Coast, running northward to the Tri-State area surrounding New York City (sections of Connecticut, New Jersey and New York State) will also be observing their Hurricane Awareness Weeks during this week. The New England States (Connecticut, Maine, Massachusetts, New Hampshire and Rhode Island) and the remainder of New York State will have their Hurricane Awareness Weeks in mid-July.
• Second NOAA Hurricane Awareness Webinar for 2021 runs this week -- NOAA is presenting the second webinar in its Southeast and Caribbean Regional Team (SECART) Hurricane Awareness Webinar series for 2021 this Monday afternoon (10 May 2021 at 1-2 PM EDT). This one-hour webinar will be delivered in Spanish and is entitled "¿Cómo se está recuperando Puerto Rico? Cuatro años después del huracán Maria." ("Recovery efforts in Puerto Rico, Four years after Hurricane Maria"). The meteorologist-in-charge of the San Juan (Puerto Rico) National Weather Service Forecast Office and a civil engineering professor at the University of Puerto Rico at Mayagüez will discuss how Puerto Rico is still recovering from the aftermath of Hurricane Maria that devastated the island in 2017. Registration is required. [NOAA]
• "Hurricanes at Home!" webinars from National Hurricane Center are aimed at middle school students -- The National Hurricane Center will be conducting free one-hour webinars about hurricanes for 4th, 5th, and 6th graders who are learning in school or at home in states and U.S. territories bordering the Gulf and Atlantic coasts. These webinars will be directed toward students in Florida, Puerto Rico and the U.S, Virgin Islands. During this upcoming week, an English version will be shown on Wednesday afternoon (12 May at 4 PM EDT), while a Spanish version will be broadcast the following afternoon (13 May at 4 PM EDT). During the following week, the English version will be shown Tuesday afternoon (18 May at 4 PM EDT). Registration links are available and should be used. [NOAA National Hurricane Center]
• Zenithal Sun -- This week marks one of the two times during the year when the noontime sun is directly overhead to residents on the Big Island on about 14 May at South Cape (Ka Lae at 18.9 degrees North latitude and 155.68 degrees West longitude) and on 18 May at Hilo; those on Oahu (Honolulu metropolitan area) will experience the noon sun at the zenith in approximately two more weeks (25-27 May). The sun will again be over the Big Island during the last week of July. [timeanddate.com]

CLIMATE MONITORING

• New NOAA Climate Normals for 1991-2020 have been rolled out last week -- After much anticipation, NOAA's National Centers for Environmental Information (NCEI) released the new Climate Normals for 1991-2020 last Tuesday, updating and replacing the previous normals for 1981-2010. These new normals are quality-controlled average values of temperature, precipitation, degree-day units and other observed or calculated weather variables for the 30 years running from 1991-2020. Normals are calculated for annual, seasonal, monthly, daily and hourly time-steps. With heightened interest in climatic change, discussion also focuses on how these new climate normals reflect changes in the climate:
• Gaining an understanding of climate normals -- NOAA posted a four-part feature to provide some background information concerning the recently released NOAA Climate Normals for 1991-2020. These four parts correspond to four questions that are often asked: 1.) What are climate normals? 2.) How are climate normals calculated? 3.) What are the changes in the 1991-2020 update? and 4.) What do climate normals say -- and don't say -- about climate change? [NOAA Explainers ]
  Some additional information concerning climate normals and climate change is available. [NOAA News]
• Graphics show the changes in the normals over the last 120 years -- Climate Central, a non-profit organization of climate scientists and science journalists have produced a set of graphics that can be used by the media to convey to the public some of the features associated with NCEI's new set of 1991-2020 climate normals released earlier last week. In addition to the attractive and relatively simple to understand graphics that can be used by the local media, the scientists provide some discussion to help put weather into the context of the current “normal” climate. In addition, these graphics and accompanying discussion are meant to illustrate how warming over the last several decades has been accelerating with climate change. One set of graphics, identified as "National Warming Trends," contains two maps of the 48 contiguous United States, with one map showing the difference (in Fahrenheit degrees) between the normal average annual temperatures for the 1991-2020 interval and the corresponding normals for the 1901-1930 interval, which was the first 30-year "normals" computed by the predecessor to NCEI. Most of the nation experienced warming of the last 120 years, with areas near the U.S.-Canadian border having increases of nearly 3 Fahrenheit degrees. The other map displays the difference between the average annual temperatures for the 1991-2020 interval and that for 1981-2010. This map shows that the warming since the 1981-2010 normals has not been as drastic over the longer period, with some areas across the northern Plains and Upper Midwest having several tenths of a Fahrenheit degree increase in temperature.
  The other set of Climate Center graphics are identified under the heading "Local Normal Anomalies" and include graphs of the differences in the average annual temperatures from the 20th century average (1901-2000) for each of the ten normal periods (1901-1930, 1911-1940, ..., 1991-2020) at 242 large city airport weather stations. Slightly more than 75 percent of these stations experienced an increase of more than one Fahrenheit degree in their normal annual average temperatures since the beginning three decades of the 20th century. [Climate Central]
• International organization recommends frequent updates to 30-year normals -- Until recently, the United States has been one of the few nations to update their 30-year climate normals every ten years, with many nations recalculating their climate normals once every 30 years. However, the World Meteorological Organization (WMO) is now recommending that the 30-year standard reference periods should be updated every decade to better reflect the changing climate. [WMO News]

CLIMATE FORCING

• Carbon intensity of the nation's power sector continues to fall in 2020 -- The 2020 Carnegie Mellon Power Sector Carbon Index, which was recently released by Carnegie Mellon University (with support from Mitsubishi Hitachi Power Systems), reveals that U.S. power plant emissions averaged 813 pounds (lb) of carbon dioxide (CO₂) per megawatt hour (MWh) during the last quarter of 2020, which was down four percent from the corresponding last three months of 2019. Furthermore, the Power Sector Carbon Index for the fourth quarter of 2020 was 38 percent lower than in the annual value of 1,321 lb CO₂ per MWh in 2005, the benchmark year for measuring progress made in reducing emissions. This Index tracks the environmental performance of U.S. power producers and compares current emissions to more than two decades of historical data collected nationwide. A summary of how much electricity generation is from coal, natural gas, nuclear, and renewables. [Carnegie Mellon University College of Engineering News]
• Reduction in human-caused atmospheric methane this decade is possible -- The Climate and Clean Air Coalition (CCAC) and the United Nations Environment Programme (UNEP) recently released its Global Methane Assessment showing human-caused methane (CH₄) emissions can be reduced by as much as 45 per cent this decade. Such a reduction would avoid nearly 0.3°C of global warming by 2045 and would be consistent with keeping the Paris Climate Agreement’s goal to limit global temperature rise to 1.5 Celsius degrees. Furthermore, with methane being a key ingredient in the formation of ground-level ozone (smog), a powerful climate forcer and dangerous air pollutant, a 45 per cent reduction of its emissions would prevent 260 000 premature deaths. [WMO News]

CLIMATE FORECASTS

• South Asian regional climate outlook calls for near- to above-average rainfall for southwest monsoon season -- Forecasters for all nine National Meteorological and Hydrological Services of South Asian countries released a new South Asian regional climate outlook early last week that indicates normal to above-normal rainfall appears most likely across many northern sections of South Asia especially along the foothills of the Himalayas during the upcoming 2021 southwest monsoon season (June – September). This Southwest Monsoon accounts for 75-90 per cent of the annual rainfall in most parts of the region, making the monsoon circulation an all-pervading influence on the socio-economic fabric of the region. The outlook indicating near to above normal rainfall is based upon the majority of global climate model forecasts indicating that the weak La Niña should transition to ENSO-neutral conditions, which would likely prevail during the upcoming southwest monsoon season. [WMO News]

CLIMATE AND SOCIETY

• Earthweek -- Diary of the Planet [earthweek.com]

Historical Events:

• 10 May 1910...A meteorograph ascent of an instrumented Weather Bureau kite to 23,835 feet from Mount Weather, VA set the altitude record for the site. The ascent, which had a kite with instruments to measure atmospheric conditions aloft, used 10 kites in tandem and 8.5 miles of kite wire. (Accord's Weather Guide Calendar)
• 10 May 1966...Morning lows of 21 degrees at Bloomington-Normal and Aurora established an Illinois state record for the month of May. Snow flurries were reported at Kansas City, MO and Chicago, IL (The Weather Channel) (Intellicast)
• 10-11 May 1986...Bangkok, Thailand received 15.79 inches of rain in 24-hours, which was a national record. (The Weather Doctor)
• 11 May 1934...A tremendous dust storm affected the Plains as the Dust Bowl era was in full swing. According to The New York Times, dust "lodged itself in the eyes and throats of weeping and coughing New Yorkers," and even ships some 300 miles offshore saw dust collect on their decks. (National Weather Service files)
• 11 May 1966...The 1.6 inch-snow at Chicago, IL was their latest measurable snow of record. Previously the record was 3.7 inches on the 1^stand 2^nd of May set in 1940. (The Weather Channel)
• 11 May 2003...A total of 4.63 inches of rain fell at Nashville, TN, breaking the previous 24-hour record for the month. (The Weather Doctor)
• 12 May 1916...Plumb Point, Jamaica reported 17.80 inches of rain in 15 minutes, which set a world record. (The Weather Doctor)
• 13 May 1930...A man was killed when caught in an open field during a hailstorm 36 miles northwest of Lubbock, TX. This event was the first, and perhaps the only, authenticated death by hail in U.S. weather records. (David Ludlum)
• 13 May 1992...Record late season snow ended over the Tanana Valley and Yukon Uplands in Alaska. This storm set two records at Fairbanks. The 9.4 inches of snow from the storm was by far the greatest May snow on record, shattering the previous record of 4.5 inches set on 13 May 1964. The total water content of the melted snow and rain was also a new one-day record for May (0.78 Inches). Snowfall in excess of two feet occurred at elevations above 2000 feet. (Intellicast)
• 14 May 1834...The greatest snowstorm ever to occur in May hit the Northern Atlantic coastal states. The hills around Newbury, VT were covered with up to 24 inches of snow and the higher elevations around Haverhill, NH received up to three feet. (Intellicast)
• 14 May 1896...The mercury plunged to 10 degrees below zero at Climax, CO, the lowest reading of record for the U.S. during the month of May. (David Ludlum) This record has since been broken in May 1964 by a reading of 15 degrees below zero at White Mountain in California. (NCDC)
• 14 May 2001...A storm stalled south of Nova Scotia drenching Halifax with 3.89 inches of rain, the greatest daily May rainfall since records began in 1871. (The Weather Doctor)
• 15 May 1968...Only tornado of record to have ever touched down in Alaska was spotted near Anchorage. (The Weather Doctor)
  Check A tornado touched down southwest of Anchorage, Alaska. It was the second of just three tornadoes reported in Alaska since 1950. (National Weather Service files)
• 16 May 1917...Marquette, MI had its latest opening of navigation on Lake Superior in history. (Intellicast)
• 16 May 1924...The temperature at Blitzen, OR soared to 108 degrees to set a state record for the month of May. The record was later tied at Pelton Dam on the 31 May 1986. (The Weather Channel)