WEEKLY WEATHER AND CLIMATE NEWS

21-25 September 2020

Items of Interest:

• The Autumnal Equinox --The Autumnal Equinox occurred early this Tuesday morning (officially at 1331 Z on 22 September 2020 or 9:31 AM EDT or 8:31 AM CDT, etc.). At that time the noontime sun appeared directly above the equator, representing one of the two times during the year for such an occurrence, with the other being at the vernal equinox in March. The term "equinox" arises from the fact that this time of year represents "equal night" and equal day essentially everywhere. Within the subsequent several days, the length of daylight will become noticeably shorter. This decrease in daylight will continue for another three months to the winter solstice during the morning of Monday, 21 December 2020.
  Editor's note: John White, a meteorologist from North Carolina involved with the AMS Education program, reported that the geosynchronous (or geostationary) satellites make an "satellite eclipse" of the sun near the spring and autumnal equinoxes because of their equatorial orbit, such that these satellites pass through the earth's shadow and the satellite is powered down when the solar array does not receive sufficient sunlight. EJH.
  If you check the sunrise and sunset times in your local newspaper or from the climate page at your local National Weather Service Office, you would probably find that later this week the length of time when the Sun is above the local horizon would be precisely 12 hours at most locations. By the end of this week, the length of night will finally exceed that of the length of daylight. The effects of atmospheric refraction (bending of light rays by the varying density of the atmosphere) along with a relatively large diameter of the sun contribute to several additional minutes that the Sun appears above the horizon at sunrise and sunset.
• September is National Preparedness Month -- The month of September has been declared National Preparedness Month (NPM), which is aims to educate and empower Americans to prepare for and respond to all types of emergencies, including natural disasters and the current COVID-19 pandemic. NPM is managed and sponsored by the Federal Emergency Management Administration's (FEMA) Ready Campaign in conjunction with the Ad Council, A toolkit of marketing materials is provided to help promote the month and represents the lead on this campaign that was originally launched in 2004. The overarching theme for 2020 NPM is "Disasters Don’t Wait. Make Your Plan Today." with an emphasis on promoting family and community disaster planning during this month and throughout the year. Week 4 of the 2020 NPM runs this week (20-26 September) with the theme of "Teach Youth About Preparedness." by talking in a reassuring way to the youngsters about preparing for emergencies, especially if they are separated from other family members. [FEMA's Ready.gov]
• World Environmental Health Day to focus on air quality -- This Saturday (26 September 2020) has been declared World Environmental Health Day by the International Federation of Environmental Health. This event is celebrated each year. The theme for the 2020 World Environmental Health Day is "Environmental Health, A Key Public Health Intervention In Disease Pandemic Prevention ," which focuses upon the Environmental Health Practitioner, who plays a vital role in the implementation of disease preventive measures around the world. [International Federation of Environmental Health]
• Free admission into the National Parks -- Saturday, 26 September 2020, has been designated by the National Park Service as fee-free day in honor of National Public Lands Day, which is celebrated annually at public lands across the nation on the fourth Saturday in September. This fee waiver will cover entrance and commercial tour fees in many of the national parks and monuments administered by the Park Service. [National Park Service Fee Free Days] National Public Lands Day is an event of the National Environmental Education Foundation that promotes both popular enjoyment and volunteer conservation of public lands. [National Environmental Education Foundation]
• An activity that teaches how hurricanes and storm surges impact coastal communities -- An activity that is appropriate for middle school level (6-8) students examines the impacts of hurricanes and storm surges on coastal communities. This activity, which was developed by The Institute for Global EnvironmentalStrategies, is entitled "What Could A Hurricane Do To My Home?" A teacher's guide, assessment questions, answer key, and background information are available. [NOAA Climate.gov Teaching Climate]
• Investigating NOAA's "Global Climate Dashboard" -- A member of the staff at NOAA's Climate Program Office wrote a feature that helps the user navigate the NOAA "Global Climate Dashboard." This web-based app provides one-stop access to information, maps, and graphs of key indicators of the global climate. Interactive graphs deliver a system-wide view of the state of natural patterns like El Niño and the Arctic Oscillation and those linked to human-caused climate change, such as sea level rise and increases in greenhouse gases. [NOAA Climate.gov News]
• End of the growing season -- If you live in the northern portion of the country, the growing season may have already ended as cold air masses have moved southeastward from Canada. Check the interactive maps produced by the Midwestern Regional Climate Center's Vegetation Impact Program (VIP) that show the date of the first occurrence of 28-degree and 32-degree Fahrenheit temperature readings during this fall across the 48 coterminous United States. (Use the "Current Season Freezes" in the "Shaded Maps Menu" on left to select the desired map.) Comparison can be made with corresponding maps showing the median dates of occurrence of the first 32-degree (or 28-degree) Fahrenheit temperatures (in the appropriate "Climatologies" sections) across the lower 48 states based upon a 30-year time series. (The median date means that half of the occurrences of a 32-degree reading over the 30-year normal occur prior to this date, while the other half occur after this date.) Additional other freeze-climatology maps are available including the earliest and latest dates of first autumnal freeze. Following first frost, some delightful days should occur during October and early November in what is often called "Indian Summer."

Weather and Climate News Items:

• Eye on the tropics -- Last week continued to be an active week across the North Atlantic basin, with three hurricanes, three tropical storms, one subtropical storm and one tropical depression. The North Pacific Ocean basin was relatively quiet, with only one named tropical storm in the eastern Pacific and two tropical storms in the western Pacific.
• In North Atlantic basin (that includes the open North Atlantic, along with the Caribbean Sea and the Gulf of Mexico):
  • Hurricane Paulette, the sixth Atlantic hurricane of 2020, made a direct hit on the island of Bermuda during the predawn hours of last Monday morning as an Air Force Reserve Hurricane Hunter aircraft and Bermuda radar observed the northern eyewall of Paulette making landfall on Bermuda. At the time, Paulette was a strong category 1 hurricane (on the Saffir-Simpson Scale) with maximum sustained winds of 85 mph, as the hurricane was heading toward the northwest. Just before dawn, the entire island of Bermuda was under the central eye of Paulette. Several hours after sunrise, the southern eyewall of Paulette crossed the island. Hurricane-force winds and torrential rains battered Bermuda through the morning hours of Monday. Central pressure when Paulette passed across the island was 973 mb (or 28.74 in Hg). During the remainder of Monday, Paulette continued strengthening as it moved away from Bermuda, reaching a peak intensity as a category 2 hurricane with wind speeds reaching 105 mph. At the same time, Paulette began to curve toward the north and then to the north-northeast. Paulette weakened slowly on Tuesday, bur remained a category 2 hurricane heading toward the northeast and east-northeast until it became a strong extratropical cyclone with maximum sustained surface winds of 85 mph late Wednesday morning. At the time, this former hurricane was heading toward the east-northeast at a distance of 450 miles to the east-southeast of Cape Race, Newfoundland. Even though Hurricane Paulette remained well off the U.S. Atlantic Coast, ocean swells generated by Paulette created high surf and strong rip currents, causing a man to drown along the New Jersey shore. The NASA Hurricane Blog has satellite images and additional information on Hurricane Paulette.
  • Tropical Depression Rene was heading to the west across the tropical waters of the North Atlantic at the start of last week. As of sunrise last Monday morning, this former tropical storm was approximately 1115 miles to the northeast of the Leeward Islands. By early Monday evening, Tropical Depression Rene had dissipated, as its remnants were located 1045 miles to the northeast of the Leeward Islands. The NASA Hurricane Blog has satellite images and additional information on Hurricane Rene.
  • Tropical Storm Sally, the eighteenth named Atlantic tropical cyclone of 2020, was heading to the west-northwest across the northern Gulf of Mexico before sunrise last Monday morning By late Monday morning, a NOAA Hurricane Hunter aircraft reported that Sally had strengthened rapidly (within a timespan of less than two hours) to a hurricane approximately 135 miles to the east-southeast of the mouth of the Mississippi River, as maximum sustained surface winds were determined to have reached 85 mph. Sally had become the seventh hurricane of 2020 in the Atlantic basin. By late afternoon, Sally had reached peak intensity as a category 2 hurricane with maximum sustained winds reaching 100 mph. At that time, the center of Sally was located approximately 105 miles to the east of mouth of the Mississippi River or 145 miles to the southeast of Biloxi, MS. Minimum central pressure at peak intensity was 986 mb (or 29.12 in Hg). Sally weakened to a category 1 hurricane due to upwelling of colder Gulf water, but as it approached the Alabama Gulf Coast, it strengthened to become a category 2 hurricane for a second time early Wednesday morning while heading toward the north-northeast. In the predawn hours of Wednesday, Sally made landfall at peak intensity by Gulf Shores, AL as a category 2 hurricane with maximum sustained surface winds of 105 mph and a minimum central pressure of 965 mb (28.50 in Hg). After making landfall, Sally weakened to a category 1 hurricane and then to a tropical storm by early Wednesday afternoon as it moved slowly inland to approximately 30 miles to the north-northeast of Pensacola, FL. Eventually, Tropical Storm Sally weakened to a tropical depression by late Wednesday evening , before becoming a post-tropical cyclone late Thursday morning as this remnant low was located approximately 115 miles to the southwest of Athens, GA. Strong hurricane-force winds and storm surge flooding caused widespread damage along the coast of Alabama and the western Florida Panhandle. Over 20 inches of rain also contributed to flooding. Several tornadoes were also spawned. Additional information and satellite images for Hurricane Sally can be found on the NASA Hurricane Blog.
  • Tropical Depression -20 (TD-20) became Tropical Storm Teddy last Monday morning as it was heading toward the west-northwest across waters of the tropical Atlantic, nearly halfway between the Cabo Verde Islands and the Lesser Antilles. Over the next two days, Teddy continued to intensify as it headed toward the west-northwest and northwest. On Wednesday morning, Teddy became a hurricane as satellite-estimated maximum sustained surface winds reached 85 mph. At that time, the center of this new hurricane was located approximately 830 miles to the east of the Lesser Antilles. By early Wednesday afternoon, Teddy had strengthened to a category 2 hurricane with 100 mph. Over the next day Teddy briefly weakened back to a category 1 system, but then rapidly re-intensified into the second major Atlantic hurricane of 2020 as it became a category 3 hurricane of the season during the midday hours of Thursday. By late Thursday afternoon, Teddy reached its peak intensity as a category 4 hurricane with 140-mph maximum sustained winds and a central minimum pressure of 945 mb (27.91 in Hg). At this time, the center of Teddy was located 575 miles to the northeast of the Lesser Antilles. Over the next day, Hurricane Teddy underwent fluctuations in intensity as it headed to the northwest toward Bermuda before showing signs of weakening on Saturday. By early Sunday, Teddy had weakened to a category 2 hurricane as it was 320 miles to the southeast of Bermuda. As of late Sunday night, Hurricane Teddy remained a category 2 hurricane with sustained winds of 105 mph as it was slowly turning toward the north-northwest, heading toward Bermuda. At the time, Teddy was approximately 210 miles to the south-southeast of that island. However, Teddy was forecast to begin curving to the north on Monday, passing to the east of Bermuda on Monday morning. Gradual weakening of Teddy was anticipated, beginning by midweek. Additional information and satellite images for Hurricane Teddy are available on the NASA Hurricane Blog.
  • Tropical Depression 21 (TD-21) formed over the far eastern tropical North Atlantic on last Monday morning. TD-21 traveled to the north and strengthened to Tropical Storm Vicky, the twentieth named tropical cyclone of the 2020 hurricane season as it was approximately 350 miles to the west-northwest of the Cabo Verde Islands. Vicky intensified as it began traveling toward the northwest, reaching peak intensity with maximum sustained winds of 50 mph beginning early Tuesday morning. Over the next day, Vicky experienced some slight variations in intensity as it was heading toward the west-northwest and then west. Vicky began weakening on Wednesday afternoon and into Thursday. By late Thursday morning, Vicky weakened to a tropical depression and then became a remnant low by late Thursday afternoon while the center of this system was located 1050 miles to the west-northwest of the Cabo Verde Islands. Consult the NASA Hurricane Blog for more information on Tropical Storm Vicky.
  • Tropical Storm Wilfred formed early last Friday afternoon (local time) over the waters of the eastern tropical Atlantic as the 21st named tropical cyclone of 2020, but with the distinction of having the last name in the internationally-recognized 2020 list of names for Atlantic tropical cyclones. At the time of formation, Wilfred had maximum sustained surface winds of 40 mph and was traveling to the west-northwest, approximately 630 miles to the west-southwest of the Cabo Verde Islands. During the next 24 hours, Wilfred remained a minimal tropical storm as it continued toward the west-northwest. Wilfred weakened to a tropical depression during the midday hours of Sunday. By late Sunday night, Wilfred had degenerated into a low pressure trough approximately 925 miles to the east of the Lesser Antilles.
  • The 22nd tropical depression of 2020, labeled TD-22, formed over the southwestern Gulf of Mexico early Thursday evening approximately 230 miles to the east of Tampico, Mexico. Over the next 20 hours, TD-22 strengthened as it headed toward the north and then north-northeast, becoming Tropical Storm Beta by Friday afternoon as maximum sustained surface winds had reached 40 mph as the system was approximately 280 miles to the east-southeast of the mouth of the Rio Grande River (near Brownsville, TX). Tropical Storm Beta is the 22nd or 23rd named tropical or subtropical cyclone of 2020, reaching this status shortly after TD-22 became Subtropical Storm Alpha; see the paragraph below for more details on Alpha. By late Sunday evening, Tropical Storm Beta was continuing to head to the west-northwest toward the Texas Gulf Coast. At that time, Beta was located approximately 120 miles to the south of Galveston, TX. Maximum sustained surface winds remained at 60 mph. Beta could reach the central Texss coast by Monday night, with little change in intensity. A sharp turn of Beta to the north and northeast was possible by late Monday. Once onshore, Beta should weaken rapidly. In addition to tropical-storm-force winds, storm surge could create coastal flooding. The NASA Hurricane Blog has additional information for TD-22, which then became Tropical Storm Beta.
  • Subtropical Storm Alpha formed late Friday afternoon (local time) over the waters offshore of the coast of Portugal, or 75 miles to the west of the national capital city of Lisbon. The National Hurricane Center identified this system as a subtropical storm as this non-frontal low-pressure system with maximum sustained surface winds of at least 39 mph and had characteristics of both tropical and extratropical cyclones. Furthermore, giving this subtropical storm a name corresponding to a Greek letter for identification purposes was only the second time that the name Alpha was used, with the first being in the very active 2005 season. Moving toward the northeast, Subtropical Storm Alpha made landfall along the Portuguese coast 120 miles to the north-northeast of Lisbon late Friday evening, slightly more than four hours after it formed. At landfall, maximum sustained surface winds were determined to be 45 mph. Nearly six hours after landfall, Subtropical storm Alpha became a remnant low over district of Viseu Portugal during the predawn hours of Saturday morning. Additional information and a satellite image of Subtropical Storm Alpha can be found on the NASA Hurricane Blog.
• In eastern North Pacific basin (located off the western North American continent and extending westward to the 140-degrease West meridian):
  • Tropical Storm Karina, the eleventh named tropical cyclone for the basin in 2020, continued traveling toward the west-northwest away well off the coast of Mexico at the start of last week. During the next 48 hours, Tropical Storm Karina reached a peak intensity with maximum sustained surface winds attaining a speed of 60 mph on Wednesday morning as the center of Tropical Storm Karina was approximately 740 miles to the west of Cabo San Lucas, Mexico. Karina weakened rapidly as it continued on a track generally toward the west-northwest, becoming a tropical depression on Wednesday afternoon when sustained surface winds dropped to 35 mph. Within six hours, Tropical Depression Karina became a post-tropical cyclone or remnant low pressure system on Wednesday night as it was nearly 960 miles to the west of the southern tip of Mexico's Baja California Peninsula. Consult the NASA Hurricane Blog for additional information and satellite images on Tropical Storm Karina.
• In the western North Pacific (extending from the International Dateline westward to the Asian continent):
• An area of low pressure formed late last Tuesday (local time) over the waters of the Philippine Sea, which then became Tropical Depression TD-13W as it headed westward across the Philippine Archipelago. On Wednesday, TD-13 strengthened to become Tropical Storm Noul as it was moving to the west across the South China Sea. Over the next 48 hours, Noul continued strengthening to weak intensity with 50-mph sustained surface winds as it took a track to the west-northwest toward the coast of central Vietnam. Tropical Storm Noul made landfall on Friday afternoon along the north central coast of Vietnam just to the ancient city of Hue. Strong winds caused damage in Hue and 12.20 inches of rain fell in nearby Da Nang. As of late Friday night, Tropical Storm Noul had moved across Vietnam and into Laos. Noul weakened due to a wind shear in the atmosphere and was becoming disorganized as it encountered mountainous terrain approximately 200 miles to the west of Da Nang, Vietnam, when it became a post-tropical cyclone. Additional information and satellite imagery on Noul is available on the NASA Hurricane Blog.
• Tropical Storm 14W formed late Sunday night from a tropical depression slightly more than 400 miles to the east-southeast of Okinawa. This tropical storm was traveling toward the north-northwest. As of Monday, Tropical Storm 14W, which was given the local name Marce, was traveling northward across the western North Pacific, approximately 400 miles to the east-southeast of Okinawa. This system was forecast to continue to the north toward the main Japanese Islands as a tropical storm on Monday and Tuesday.
• US national weather and climate reviewed for August and Summer 2020 -- Based upon preliminary data, scientists at NOAA's National Centers for Environmental Information (NCEI) report that August 2020 was the third warmest August across the contiguous United States since sufficiently reliable climate records began in 1895. The nationwide August 2020 average temperature was 74.7°F, which was 2.6 Fahrenheit degrees above the 20th-century (1901-2000) average. The average maximum (or daytime) temperature for the "Lower 48 States" last month was the fifth highest of record for any August. Record high statewide average August maximum(or daytime) temperatures were set in seven states across the Southwest (Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming). The average minimum (or nighttime) temperature for the contiguous states was the fifth highest value for any August in 126 years. Arizona, California, Nevada and Utah had statewide average August minimum temperatures that were the highest in their respective states since 1895.
  The majority (38) of the contiguous states reported statewide average August temperatures that ranged from above to much above average temperatures. Arizona, California, Colorado, Nevada, New Mexico and Utah had record high statewide average August temperatures. that ranked within the 126-year periods of record of these respective states. A dozen other states scattered across the West and along the East Coast experienced statewide August average temperatures that were in the top ten for their respective states since 1895. On the other hand, Arkansas, Missouri and Oklahoma had below average August temperatures. The remaining seven states, in the central Plains, Midwest and lower Mississippi Valley had near average temperatures for the month.
  Alaska had its 11th warmest August since 1925 with an average August temperature of 52.1°F, which as 2.6 Fahrenheit degrees above the long-term average.
  The recently concluded meteorological summer of 2020 (June, July and August) was the fourth warmest summer since 1895, with a three-month average temperature of 73.6°F, which was 1.0 Fahrenheit degrees above the 20th century average. All but three of the states in the "Lower 48 States" had statewide average summer temperatures that were above or much-above the long-term average. Arizona, Connecticut, Massachusetts and Rhode Island experienced their hottest summers in 126 years. Another 25 states across the West, the Plains, Midwest and Eastern Seaboard had summer statewide average temperatures that ranked in the top 13 on record for their respective states. Only three states (Arkansas, Missouri and Oklahoma) had near-average summer temperatures.
  Alaska reported a statewide average temperature for the summer was 52.0°F, making this past summer its 16th warmest in 96 years.
  The August 2020 average precipitation for the contiguous U.S. was 2.35 inches, or 0.27 inches below the 20th-century average, which meant that this past month was the 28th driest August in 126 years. With a few exceptions, most of the states to the west of the Mississippi River (16) had below to much-below statewide precipitation totals. Arizona, Utah and Nebraska set record low precipitation totals for their respective states. Seven other states running along the spine of the Rockies and across the Plains to the Midwest had August statewide precipitation totals that ranked in the driest 13 on record. Five of the New England States also had below average precipitation. However, seventeen states running from the Mississippi Valley to the Eastern Seaboard had above to much-above average statewide monthly precipitation totals for August 2020. Arkansas, Maryland, North Carolina, Virginia and West Virginia had statewide rainfall amounts that ranked within their 12 greatest totals since 1895.
  Alaska had its 41st driest August since 1925.
  The nationwide summer (JJA) 2020 precipitation was 0.33 inches below the 1901-2000 average, which was makes this past summer the 33rd driest across the "Lower 48 States" since 1895. Eleven states located to the west of the Mississippi River had below to much-below average summer precipitation. Arizona experienced its driest summer on record, while adjacent states were having the lowest summer rainfall totals that were within the lowest 13 summers on record. In addition, eight states in New England and those bordering the eastern Great Lakes had below to much-below summer rainfall. On the other hand, 16 states scattered primarily across the nation's midsection and in the Middle Atlantic coast had statewide summer precipitation totals that were above to much-above average. Virginia had its tenth wettest summer, while Maryland had its thirteenth wettest. The remainder of the states had statewide precipitation totals close to average.
  Alaska reported its 32nd wettest summer since 1925.
  [ NOAA/NCEI State of the Climate] NOTE: A description is provided of the climatological rankings employed by NCEI for their monthly and seasonal maps. [NOAA/NCEI]
  A map entitled "U.S. Selected Significant Climate Anomalies and Events for August and Summer 2020" graphically summarizes several significant weather and climate events that occurred across all 50 states and Puerto Rico during August.
• August national drought report -- The National Centers for Environmental Information posted its August 2020 drought report online. Using the Palmer Drought Severity Index, approximately 19 percent of the coterminous United States experienced severe to extreme drought conditions at the end of August, while 19 percent of the area had severely to extremely wet conditions.
• Solar Cycle 25 begins -- Solar physicists, who are part of the Solar Cycle 25 Prediction Panel co-chaired by NOAA’s Space Weather Prediction Center and NASA, announced last week that the 13-month smoothed sunspot number fell to 1.8 when the Sun was least active last December. Solar cycles are periodic variations in Sun's magnetic field that are roughly 11 years in length and which affect activity on the surface of the Sun, such as upon the number of sunspots. The solar cycles are identified by number, commencing with Solar Cycle 1 that began when regular record keeping of sun spot activity began in 1755. Solar Cycle 24, which began in December 2008, ended late last year after reaching a maximum in April 2014. The new Solar Cycle 25 began in December 2019, when the Sun was determined to be least active. The solar physicists predict that the maximum in Solar Cycle 25 should occur in July 2025, with a peak of 115 sunspots. [NOAA National Weather Service News]
  Additional information on solar cycles and of their importance to planet Earth can be found in the feature "What's the Big Deal about Solar Cycles on the NOAA National Environmental Satellite, Data, and Information Service (NESDIS) website. [NOAA NEDIS News]
  A list of five notable times since September 1859 when solar activity involving solar flares and coronal mass ejections (CMEs)from the Sun's surface has created havoc on planet Earth, especially involving disruptions in electrical communications and power grids. [NOAA NESDIS News]
• New Seasonal (3-month) Climate Outlooks for the remainder of 2019 issued -- Forecasters at the NOAA Climate Prediction Center (CPC) recently released their new national Three-Month (Seasonal) Climate Outlooks for October through December 2019, corresponding to the last two months of the meteorological autumn season (in the Northern Hemisphere) and the first month of meteorological winter. Specific details of their outlooks include:
  • Temperature and precipitation outlooks -- According to their temperature outlook, the entire contiguous United States should experience a high chance of above-average temperatures for the three upcoming months. The greatest probability of such an occurrence should be found across the Southwest, centered upon the Four Corners (Arizona, Colorado, New Mexico and Utah) and in northern New England and Upstate New York. The North Slope of Alaska along with western sections of that state were envisioned to have the highest chances of above average temperatures. On the other hand, southeastern Alaska including the Alaska Panhandle was anticipated to have "Equal Chances" (EC) of below, near or above average temperature.
    The CPC precipitation outlook calls for a better than even chance for below average precipitation during the next three months across the southern tier of states extending from southern California to Georgia, with the largest chance for a drier than average end to 2020 being centered over New Mexico and Texas. On the other hand, the Northwest would have a good chance of above average precipitation through the end of the year, with the highest probability stretching from the Puget Sound area of western Washington eastward to eastern slopes of the Montana Rockies. The remainder of the contiguous states were given essentially equal chances of below, near or above average precipitation for October through December 2020. Northern and western Alaska could experience above average precipitation during the next three months, while no clear predictive signal is available for the remainder of the 49th State, leading to the "EC" designation.
    A summary of the prognostic discussion of the 3-month outlook for non-technical users is available from CPC. These forecasts were based upon the expectation of a continuation of the current La Niña conditions through Northern Hemisphere winter, with atmospheric and oceanic circulation patterns recognizable by below average sea surface temperatures (SST) across the eastern and central tropical Pacific Ocean. The precipitation outlook with dry conditions across the southern tier of states and wet weather along the northern states reflects a La Niña-type winter pattern. In addition, long-term trends in temperature and precipitation also enter into the seasonal outlooks.
    A description is also provided as how to read these 3-class, 3-month Outlook maps.
  • Seasonal Drought Outlook released -- The forecasters at NOAA's Climate Prediction Center also released their US Seasonal Drought Outlook last week that would run from late-September through December 2020. Their outlook would call for persistence of the current drought conditions found across large sections of the Southwest and the Plains; this past week's U.S. Drought Monitor map provides the current extent and intensity of the drought. Areas extending from northern California eastward across the Great Basin, the Colorado Plateau and the southern Rockies should continue to experience drought, with anticipated expansion across southern California along with the southern and central Plains to the east of the Rockies into the lower Mississippi Valley. Drought conditions were also expected to continue across scattered sections of the northern Plains and Midwest. However, drought conditions across Washington, Oregon, Idaho and Montana should either ameliorate, or be removed from drought status by the end of the year. The current drought conditions across New England could also improve and terminate. Areas across the Southeast and the Middle Atlantic do not appear to be headed for drought conditions. Note: a Seasonal Drought Outlook Discussion is included describing the forecasters' confidence.
  • Determining the contribution of global aviation to climate change -- An international team of researchers conducted a comprehensive analysis of the global aviation industry’s contributing factors to climate change, including emissions of carbon dioxide and nitrogen oxide, along with the effect of contrails and contrail cirrus – short-lived clouds created in jet engine exhaust plumes. The researchers calculations found that global air travel and transport are responsible for 3.5 percent of all drivers of climate change from human activities. Furthermore, two-thirds of the impact from aviation can be attributed to contrails, nitrogen oxide, water vapor, sulfate aerosol gases, soot and other aerosols, while the remainder would be due to the cumulative heat-trapping effects of long-lived carbon dioxide emissions. [NOAA Research News]
  • Estimating height of future sea level rise from melting polar ice -- A team of glaciologists, oceanographers, and climatologists from 13 countries recently published an estimate of the contribution of melting polar ice to the rise in sea level over the remainder of the 21st century. Estimates of total sea rise due to melting in Antarctica and Greenland range from 16 to 20 inches, but these estimates do not include continual sea level rise due to thermal (heat) expansion of the oceans. [French National Centre for Scientific Research (CRNS) News]
• An All-Hazards Monitor-- This Web portal provides the user information from NOAA's National Weather Service, FAA and FEMA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [NOAA/NWS Daily Briefing]
• Earthweek -- Diary of the Planet [earthweek.com]