WEEKLY WEATHER AND CLIMATE NEWS

15-19 April 2019

Items of Interest:

• Becoming AWARE -- During this coming week of 14-20 April 2019, Colorado and Delaware will conduct Severe Weather Awareness Week in their respective states. These weeks are usually scheduled before the onset of the severe weather season in that particular state. If you live in either of these states, you should take time to become familiar with the various public affairs announcements issued by your local National Weather Service Office. By this point in spring, most of the other states have observed their Severe Weather Awareness weeks, with fewer than one dozen states yet to conduct their weeks.
• Free admission into the National Parks and Monuments-- In observance of National Park Week (20-28 April 2019), the National Park Service will waive entrance fees this coming Saturday (20 April). 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]

Weather and Climate News Items:

• "Spring" comes to interior Alaska -- The ice on the Tanana River at the community of Nenana, AK officially went out early Sunday morning, 14 April 2019, at 12:21 Alaska Standard Time. A webcam provides a continuously updated view of the official tripod set up on the river ice that will be used to officially determine the winner of the famous Nenana Ice Classic. [Nenana Ice Classic]
  This year's ice out date represents the earliest breakup on record in the famous 103-year history of the event. Only six years ago the latest breakup on record was on the afternoon of 20 May 2013. The median date for ice-breakup is 4 May.
  The jackpot for this year's annual Nenana Ice Classic could be an estimated $360,000 that will be shared by several winners who will be identified within several weeks. [Anchorage Daily News]
  NOTES: Four years ago, a feature was posted on the Climate.gov ClimateWatch Magazine site that provided additional background information on the Ice Classic and showed an analysis of long-term trends on the ice out date. An updated graph of the date of ice-out for each year since the Classic was started in 1917 has been plotted by this editor. Interannual (year-to-year) variability in ice-out dates associated with changes in winter temperature and snowfall accumulation in interior Alaska are superimposed upon the nearly century long trend in earlier ice out-dates associated with long-term climate changes. EJH
• Strong winds create large blowing dust event in Southwest -- A powerful late winter storm that traveled across the southern Rockies and into the nation’s midsection this past week carried dust from the deserts across the Southwest to the Upper Midwest. Winds of 60 to 70 mph across New Mexico and Texas on 10 April generated large quantities of dust, reducing visibility to near zero on many highways across the southern Rockies and regions of the southern and central Plains. Some of the dust was found in the snow falling across the Dakotas, Minnesota and Wisconsin. Animations using satellite images obtained by sensors on NOAA’s GOES East satellite shows the dust from Arizona and New Mexico being carried toward the northeast across the Texas and Oklahoma Panhandles. Note: Some of the animations may take time to load. EJH [CIMMS Satellite Blog]
• Eye on the tropics -- Last week was relatively quiet in terms of tropical cyclone activity, as only one tropical cyclone was found moving across the eastern South Indian Ocean basin. Tropical Cyclone Wallace, which had tropical storm-force winds, was traveling toward the west-southwest at the start of last week, well off the Kimberley and Pilbara coasts of Western Australia. At that time, Wallace was approximately 640 miles to the north-northeast of Learmonth, Australia. Wallace intensified briefly to become a category 1 tropical cyclone on the Saffir-Simpson Scale on Tuesday as maximum sustained surface winds reached an estimated 75 mph. Continuing toward the west-southwest, Wallace weakened and by Thursday, Wallace had weakened to a remnant low that ultimately dissipated approximately 400 miles to the north-northwest of Learmonth. Satellite imagery and additional information on Cyclone Wallace can be found on the NASA Hurricane Blog.
• March 2019 weather and climate for the nation reviewed -- Scientists at the NOAA National Centers for Environmental Information (NCEI) recently reported on their analysis of preliminary weather data collected during the month of March 2019. When averaged across the contiguous United States, the monthly temperature for March 2019 was 40.7 degrees Fahrenheit, which was 0.8 Fahrenheit degrees below the 20th-century (1901-2000) average. Therefore, this past month was the 44th coldest March since a comprehensive climate network began in 1895. A majority (39) of the 48 contiguous states reported statewide March average temperatures that were near average. Seven states, running from Washington eastward and southward to the Arkansas and Kentucky, had below average monthly temperatures. Only Arizona and New Mexico had statewide average temperatures that were above average.
  The average maximum (or daytime) temperature for this past March across the "lower 48" was the 41th lowest on record, while the average minimum (or nighttime) temperature was the 49th highest. Washington reported its 13th lowest minimum monthly temperature on record, while New Mexico had its 17th highest minimum monthly temperature in 125 years.
  Alaska reported its warmest March in their 95-year period of record, with a monthly statewide average temperature of 26.7 degrees Fahrenheit, which was 15.9 Fahrenheit degrees above the long-term average.
  The average precipitation across the contiguous U.S. for March 2019 was 2.20 inches, which was 0.31 inches below the 20th-century average, making the month the 34th driest March since 1895. Twenty-three states scattered across the Northwest, the Gulf Coast States and the Northeast reported below to much below-average precipitation. Montana had its second smallest March statewide precipitation average on record, followed by Washington was the fourth smallest. On the other hand, thirteen states stretching from California eastward and northward to the Midwest had above to much above average statewide precipitation totals. Utah reported its second highest precipitation total, while Colorado and Nebraska had their sixth largest precipitation totals in the 125-year record.
  Data analyzed by the Rutgers Global Snow Lab indicate the March snow cover extent across the contiguous US was the sixth highest areal extent for the 53-year period of record across the 48 contiguous states, as well as being the largest March snow cover extent since 1979. Above-average snow cover was reported across much of the West, Rockies, Great Plains, Midwest and Northeast, while below-average snow cover was observed across parts of the Southern Rockies and Ohio Valley.
  [State of the Climate NOAA/NCEI]
  NOTE: A description is provided of the climatological rankings employed by NCEI for their monthly and seasonal maps. [NOAA/NCEI]
• March national drought report -- The National Centers for Environmental Information has posted its March 2019 drought report online. Using the Palmer Drought Severity Index, approximately two percent of the contiguous United States experienced severe to extreme drought conditions at the end of March, while approximately 23 percent of the nation had severely to extremely wet conditions at that time.
• Nation experiences two new billion-dollar disasters attributed to weather and climate during first quarter of 2019 -- NOAA’s NCEI recently reported that during the first three months of 2019, the United States experienced two weather and climate disasters, each resulting in losses that exceeded $1 billion. One of these events occurred in February 2019, as widespread damage was caused by severe weather and flooding in the South (Alabama, Mississippi and Tennessee) and high winds across Ohio Valley (Illinois, Indiana and Ohio) and Northeastern states (Connecticut, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Virginia and West Virginia). A second event was the historic Midwest flooding that began in March due to a "bomb cyclone" and continues into April, with Iowa, Minnesota, Missouri, Nebraska, South Dakota and Wisconsin experiencing the greatest damage to agriculture, communities and infrastructure.
  NOTE: NCEI also added a July 1993 severe weather event to the list. This severe weather event was accompanied by strong winds, large hail and tornadoes that struck the northern and central Plains and the Ohio Valley. [NOAA News] and [NOAA NCEI Billion-Dollar Disasters]
  The NCEI list of billion disaster events in the U.S. beginning in 1980 and running through early April 2019 is available.
• Approximately 25 meteotsunamis slam East Coast annually -- Scientists at the NOAA National Ocean Service's Center for Operational Oceanographic Products and Services created a meteotsunami climatology for the U.S. East Coast based upon their analysis of 22 years (1996-2017) of water level observations from 125 NOAA and partner tide gauges located on the East Coast, extending from Maine southward to the Florida Keys. A meteotsunami is a tsunami-like sea wave of meteorological origin that generally would be generated by rapid changes in barometric pressure resulting in a displacement of a mass of water. The researchers found that the U.S. East Coast experiences an average of approximately 25 meteotsunamis per year. Most of these meteotsunamis are less than 18 inches in height, with only one per year having a height exceeding two feet. [NOAA News]
  For additional background information on meteotsunamis, check [NOAA National Ocean Service Facts]
• Higher than average tides expected along U.S. East Coast late this week -- According to the NOAA National Ocean Service's High Tide Bulletin for Spring 2019, higher than average tides are expected late this week (18-21 April). These higher than average tides should be found in the nation's Atlantic coastal waters extending from Maine southward to the east coast of the Florida Peninsula. The remainder of the nation's Pacific and Gulf Coasts will not be affected this month by higher than average tides. One of the reasons for higher than average tides is the fact that the Moon will reach the full moon phase on Friday morning (19 April 2019) at 1112Z (7:19 AM EDT or 6:19 AM CDT, etc.). Since lunar perigee (when the Moon is closest to Earth in its elliptical orbit) occurred two and a half days earlier (on the 16th), the spring tide will not be as high the perigean spring tides that occurred during the last several months when full moon occurred within a day of perigee. [NOAA National Ocean Service News]
• Updated El Niño/Southern Oscillation (ENSO) Diagnostic Discussion is released -- Late last week forecasters at NOAA's Climate Prediction Center (CPC) and the International Research Institute for Climate and Society (IRI) released their monthly El Niño/Southern Oscillation (ENSO) Diagnostic Discussion. They reported that El Niño conditions prevailed through March 2019 as above-average sea surface temperatures (SSTs) were reported across most of the equatorial Pacific Ocean, with relatively small areas in the western Pacific near Indonesia and in the eastern Pacific off the South American coast having below average SST values. Additionally, atmospheric conditions involving anomalous convection and wind regimes across the tropical latitudes of the Pacific basin were consistent with El Niño. Many of the prediction models used by the forecasters indicate a weak El Niño would have a 65 percent chance of continuing through this upcoming North Hemisphere meteorological summer (June through August) and into boreal autumn with a 50 to 55 percent chance. Consequently, the CPC's ENSO Alert System Status still maintains an El Niño advisory. [NOAA Climate Prediction Center]
  Additional information is available for this alert system involving these watches and advisories.
  An ENSO blog was written by a contractor with CPC describing how both atmospheric and oceanic components of the Earth's planetary climate system are showing weak El Niño conditions in late March and at the beginning of April. She noted that with more clouds and precipitation near the International Dateline suggested a weakened Walker Circulation, an atmospheric circulation pattern running along the Equator, which favored weaker trade winds in the eastern regions of the tropical Pacific. These weaker trade winds would result in warmer waters in this region. She described how the SST anomalies (differences between observed and long-term temperatures) across the eastern Pacific were higher than the threshold that would be considered an El Niño. Attention was also directed to the subsurface layers, where subsurface temperature anomalies in the Pacific Ocean along the Equator were positive, meaning warmer than average waters to depths of at least 100 meters. [NOAA Climate.gov News]
• An El Niño forecast from Down Under -- Forecasters with the Australian Bureau of Meteorology recently reported that sea surface temperatures have remained close to El Niño thresholds in March. However, the atmosphere has shown some inconsistency in a El Niño-like response, with trade winds showing variability in strength. Using the ensemble of climate models as guidance, they foresaw El Niño conditions would continue for the next six months. Therefore, the Bureau's ENSO Outlook status remains as El Niño ALERT, meaning a 70 percent chance existed for El Niño conditions either developing or continuing. [Australian Government Bureau of Meteorology]
• Mapping the carbon footprint of cities -- Researchers from Norway, Sweden, Japan and the U.S. have created a "Global Gridded Model of Carbon Footprints" (GGMCF) that provides a globally consistent, spatially resolved (250m), estimate of carbon footprints in per capita and absolute terms across 189 countries. GGMCF incorporates existing subnational models for the US, China, Japan, EU, and UK, using sophisticated downsizing techniques. [NASA Earth Observatory]
• Satellite monitors the retreat of a shrinking Antarctic glacier -- An animation was made using satellite images obtained from the MODIS sensor on NASA's Terra satellite showing the retreat of the Pine Island Glacier along the Antarctic Peninsula from March 2000 through February 2019. Additional images documenting the glacial retreat have been obtained from the MODIS instrument on NASA's Aqua satellite and from the Operational Land Imager (OLI) on NASA's Landsat 8 satellite. [NASA Earth Observatory]
• Glacier melting in Antarctica can also be triggered by warm winds -- An international team of researchers from the U.S., Belgium, the Netherlands and France has found that warm and dry downslope foehn or chinook winds have caused significant late-season melting on Antarctica's Larsen C ice shelf in each year since 2015. The team used satellite observations and models to identify the timing of foehn winds, to estimate the amount of surface melting they produced between 1982 and 2017, and to show the effects of this melt on the snowpack. [NASA Earth Observatory]
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]