20-24 March 2023

Items of Interest:

• Becoming AWARE -- During this week (19-26 March), Michigan, Ohio and West Virginia will observe their Severe Weather Awareness Weeks. Other states throughout the nation have either conducted or will conduct their Severe Weather Awareness Weeks in the next six weeks as the spring season for severe thunderstorms unfolds.
  Ohio and Pennsylvania will be observing their Flood Safety Awareness Weeks during this week, with special activities.
• Watching for high ocean tides along some of the nation's coasts this week -- According to the NOAA National Ocean Service's High Tide Bulletin for Spring 2023, higher than average astronomical tides will develop along the U.S. Atlantic coasts as early as this past Sunday (19 March) and run through Tuesday along the Middle Atlantic Coast (Virginia north to New Jersey), followed by four days of high tides along the Northeastern Coast (New York State to Maine), beginning on Tuesday (the 21st) and continuing until Friday. Out west, only Alaska should have higher than average astronomical tides along its coast that would run from next Monday through the following Saturday. No significant tides would be found along the Southeast Atlantic and Gulf of Mexico coasts, along the Pacific Coast (California to Washington) and for the U.S. Pacific Islands (Hawaii, Guam, American Samoa, Midway, Kwajalein and Wake Island).
  Those higher than normal high astronomical tides are also accompanied by lower than normal low tides can be encountered each day; they are known as a perigean spring tides, caused by the occurrence of lunar perigee (when the Moon is closest to Earth) and either a new or full moon. Lunar perigee will occur Sunday morning (19 March at 15:17 Z or 11:17 AM EDT, 10:17 AM CST, etc.), which will be slightly more than two days before passage of the new moon (at 17:27 Z on Tuesday, the 21st). [NOAA National Ocean Service News]
• Notice the Equinox -- The vernal equinox, which marks the commencement of astronomical spring in the Northern Hemisphere, occurs Monday afternoon at 21:24Z on 20 March 2023 (5:24 PM EDT or 4:24 PM CDT, etc.).
  If you have already checked the sunrise and sunset times in your local newspaper or from the climate page at your local National Weather Service Office, you would have found that late last week, the Sun should have been above the horizon for at least 12 hours at most locations. 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.
• Looking at the Sun and seasons from a kid's perspective -- NASA's Earth Observatory has produced a feature for its EO Kids series entitled "All About That Tilt; Sun and Season" that is intended to show youngsters (ages 9 to 12 years old) how the Earth's tilt and its position in orbit around the Sun, determines seasons all around the globe. [NASA Earth Observatory EO Kids]
• Worldwide GLOBE at Night 2023 Campaign for March is underway -- The third in a series of twelve GLOBE at Night citizen-science campaigns for the calendar year 2023 continues through Wednesday, 22 March. 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. The constellations selected for this series are Orion and Gemini in the Northern Hemisphere and Canis Major and Orion 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 fourth series in the 2023 GLOBE campaign is scheduled for 12-21 April. [GLOBE at Night]
• 2023 Iditarod Race is completed -- Just after noon last Tuesday (14 March), Ryan Redington an Inupiat (or indigenous Alaskan) from Knik, AK, crossed the finish line in Nome, AK to win the 51st anniversary of the Iditarod Trail Sled Dog Race with a time of 8 days, 21 hours, 12 minutes and 58 seconds. Since this year is an odd-numbered year, the race was run on the southern route that covered approximately 998 miles from Anchorage to Nome. This Iditarod race was the first one that Redington, the grandson of the "Father of the Iditarod" has won in fifteen attempts. [Iditarod Trail Committee Press Release]
• Washington D.C. Tidal Basin cherry blossom update -- In an update issued this past Sunday, National Park Service (NPS) officials reported that many of the cherry blossoms on the Tidal Basin cherry trees were flowering, while some blossoms would need a one or two days of warm weather to reach full bloom. On Saturday, the Bloom Stage had reached the buds were reaching the Puffy White stage, which is the stage that occurs before peak bloom. With peak bloom expected to occur early this week, the earlier NPS forecast of a 22-25 March Peak Blook would be verified when 70 percent of the blossoms of the Yoshino cherry trees surrounding the Tidal Basin are open. [Cherry Blossom Watch]
  The Trust for the National Mall along with its partners, the National Park Service and The National Cherry Blossom Festival has a Cherry Blossom Bloom Cam that provides live views of the cherry trees surrounding the Tidal Basin.
• Tsunami Preparedness in the Caribbean -- The Caribbean’s 2023 tsunami preparedness activities will primarily occur during the week of 21-25 March, including the CARIBE WAVE 2023 exercise on Thursday, 23 March. Activities are being planned by Puerto Rico and the U.S. Virgin Islands, together with other Caribbean member nations/territories. [The Tsunami Zone]
  Note: Tsunami Preparedness Week in Alaska will begin this coming Sunday, 26 March.
• Observing "World Water Day 2023" -- Wednesday, 22 March 2023, has been designated by the United Nations (UN) as the annual World Water Day, which focuses on increasing public awareness about the importance of freshwater and its conservation. The theme for this year's World Water Day 2022 is "Groundwater - Making the invisible visible,". Often viewed as a hidden water resource, groundwater’s vital role will be explained in terms of water and sanitation systems, agriculture, industry, ecosystems and climate change adaptation. The value of water pertains to much more than its price. "The World Water Day 2023 campaign, called Be the change, encourages people to take action in their own lives to change the way they use, consume and manage water." The World Water Day 2023 Factsheet can be downloaded in an English version or in eight other languages. [UN-Water]
• "World Meteorology Day" 2023 -- A celebration will be held on Thursday, 23 March 2023, for World Meteorology Day 2023. This day is designated to celebrate the anniversary of the establishment of the World Meteorological Organization (WMO) on 23 March 1950. The WMO is an agency within the United Nations. This year's theme for World Meteorological Day 2023 is "The Future of Weather, Climate and Water across Generations,", spotlighting the importance of how the meteorological community can "translate science into services for society for present and future generations."
• Reflecting back on the 1993 "Storm of the Century" -- In mid-March 1993, one of the largest and most destructive winter storms struck the eastern third of the U.S., claiming more than 270 lives and causing billions of dollars in damage. After developing off the Texas Gulf Coast on 12 March 1993, this storm underwent explosive development as it traveled across the Gulf of Mexico. After reaching Florida, it headed toward the north along the U.S. East Coast. This storm spawned at least 15 tornadoes and its strong winds created a 12-foot storm surge that produced coastal flooding in Florida. Farther to the north, record snow fell along the Eastern Seaboard and the Appalachian Mountains. At least two feet of snow fell on the southern and central Appalachians. Strong winds ushered in bone-chilling cold air. Mount Washington, NH recorded a gust of 144 mph.
  To date, this storm remains the nation's second-most costly winter storm. Because of its impact, this storm was variously dubbed the "Storm of the Century", the "1993 Superstorm" or the "Blizzard of '93." NOAA's National Centers for Environmental Information (NCEI) has assembled an updated storm summary as part of the observance of the 30th anniversary of the storm. The Northeast Snowfall Impact Scale (NESIS) characterizes and ranks high-impact Northeast snowstorms. The "1993 Storm of the Century" was considered a category 5 - Extreme - storm, the highest rank possible. [NOAA NCEI News]
  NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) has assembled a collection of satellite images and animations from the NOAA fleet of Earth-observing satellites that were operating at the time. Some of the animated images of the storm were obtained from the GOES-7 satellite, a geosynchronous satellite that was launched in 1987 was located over the Equator at 112 degrees West longitude. Currently, GOES-16 and GOES-18 satellites monitor the environmental conditions over North America and the surrounding waters of the North Atlantic and North Pacific. Instruments aboard these current generation have higher resolution than those 30 years ago. An image of the storm is also available from the polar orbiting NOAA-12 satellite that was launched in 1991. The most recent polar-orbiting satellite in NOAA's fleet is NOAA-21 that was launched in 2022. [NOAA/NESDIS News]
  According to Dr. Louis Uccellini, former Director of NOAA's National Weather Service (NWS), this 1993 "Storm of the Century" was the first time a 5-day forecast was issued to a major winter storm. He notes that a new kind of weather forecasting process had been implemented to forecast this gigantic weather event five days in advance of its impact and provide storm and blizzard warnings two days in advance -- all unprecedented. Editor's Note: Dr. Uccellini was a co-developer of the NESIS and also has been a champion of the American Meteorological Society's Education Program. EJH [NOAA News]

Weather and Climate News Items:

• Eye on the tropics ---During the last week no organized tropical cyclones were detected across any of the tropical ocean basins.
`
• Review of national weather and climate for February 2023 and winter 2022-23 -- Scientists at the NOAA National Centers for Environmental Information (NCEI) recently reported on their analysis of preliminary weather data collected during the month of February 2023. They also summarized information for the three-month meteorological winter season of December 2022 and January and February of 2023. See NOAA/NCEI News for narrative or NOAA/NCEI Monthly Report for access to numerous maps and ranking tables.
• February 2023--
  • Temperature -- The nationwide average temperature for the contiguous United States for the month of February 2023 was 36.5 degrees Fahrenheit, which was 2.7 Fahrenheit degrees above the 20th century (1901-2000) average. This national average monthly temperature was the 28th highest February average temperature since comprehensive national climate records began in 1895. The nationally averaged maximum temperature (daytime highs) for February 2023 was 47.8 degrees Fahrenheit, which was the 27th highest February average daily maximum reading in the 129-year record. The nationally averaged minimum temperature (overnight lows) was 25.2 degrees Fahrenheit, which ranked as the 31st highest January average minimum temperature.
    The majority of states (34) to the east of the Rocky Mountains experienced February monthly statewide average temperatures that were above- to much-average. Of these states, 24 were in the much-above average category, with Virginia experiencing its highest statewide average February temperature on record. The rest of the states that ranked in the top thirteen (or top 10 percent) for their respective state records were found to the east of the Mississippi River, primarily along the Gulf Coast and the Eastern Seaboard. Above-average temperatures were also found along the Mississippi River and the southern Plains. On the other hand, seven states across the West, extending from California to Colorado, had statewide February average temperatures that were below-average, or in the lowest third of the record. Arizona reported its 19th lowest temperature and California its 20th lowest. The remaining seven states in the Northwest, along the Rockies and in the central Plains were near the long-term February average. In addition to having a record statewide average temperature, Virginia also has a record statewide minimum (or nighttime temperature) for February. Pennsylvania and Georgia had record statewide maximum (or daytime) February temperatures, while Virginia had a second place finish in the daytime temperatures over the last 129 years.
    Alaska had a statewide average temperature for February of 5.9 degrees Fahrenheit, which was 1.1 Fahrenheit degrees above the 1925-2000 average, making the month the 47th coldest (or 53rd warmest) February in the statewide climate record that began in 1925.
  • Precipitation -- The scientists found that last month was drier than average, as the nationwide averaged February 2023 precipitation was 1.97 inches, or 0.16 inches below the 20th century average; thus, February was the 50th driest January across the contiguous U.S. in 129 years.
    Six states that are in New England and the Middle Atlantic (New Jersey) had a dry winter with statewide February precipitation totals falling in the much-below average levels, or in the lowest ten percent of the 129-year record. The majority (18) of the contiguous states reported below-average statewide precipitation amounts this past month. Several of these states were found along the Appalachians and the Gulf of Mexico in the east, while other states with below-average winter precipitation amounts were found in the Pacific Northwest. Conversely, above- to much-average precipitation totals were found in eleven states that are located in the mid- to Upper Mississippi Valley. Wisconsin experienced its fifth highest statewide February precipitation in 129 years, followed by Iowa with their eighth largest monthly total for February and Michigan with its tenth largest statewide total for the month. The remaining eighteen states scattered across the Southwest, the Southeast, the Ohio Valley and the Middle Atlantic had near-average precipitation totals.
    The state of Alaska had above average precipitation with a statewide February average of 2.55 inches, which was 0.23 inches above the 1925-2000 average and 43rd largest in 99 years.
  • Snow cover -- The February 2023 snow cover across the coterminous United States was the 24th-largest in the 57-year period of satellite surveillance record, according to the Rutgers Global Snow Lab.
• Winter 2022-2023 --
  • Temperature -- The nationwide average temperature for the contiguous United States for the 2022-23 winter was 34.9 degrees Fahrenheit, which was 2.7 Fahrenheit degrees above the 20th century (1901-2000) average. This national average winter temperature was the eighteenth highest winter average temperature since 1895. The nationally averaged maximum temperature (daytime highs) for January 2023 was 44.9 degrees Fahrenheit, which was the twenty-first highest average daily maximum (daytime highs) winter reading in 128 winters, while the nationally averaged minimum temperature (overnight lows) was 24.9 degrees Fahrenheit, which ranked as the fourteenth highest average minimum winter temperature.
    Of the 48 contiguous states, 35 states had above- to much-above winter average temperatures. These states were found to the east of the Rocky Mountains. In fact, 30 of these states primarily found to the east of the Mississippi experienced much-above-average winter warmth, as the winter temperatures were within the top ten percent of the 128-winter distributions for each state. Connecticut and Massachusetts each had their highest winter temperatures on record. On the other side of the spectrum, three states (Idaho, Oregon and Wyoming) in the Northwest had below-average winter temperatures. The remaining ten states that were scattered across the West had average winter temperatures that ranked in the middle tercile of all 128 winter temperatures.
    Alaska reported a statewide average temperature for the 2022-23 winter of 8.1 degrees, which was 4.5 Fahrenheit degrees above the 1925-2000 average. Thus, the state had its 20th warmest winter in 98 winter seasons.
  • Precipitation -- The scientists found that the nationwide averaged winter precipitation for this winter was 7.69 inches, or 0.90 inches above the 20th century average; thus, winter 2022-23 had the twenty-second highest precipitation across the contiguous U.S. in 127 winters.
    Nine states stretching from California to the Upper Midwest had much-above or record winter precipitation totals, which represent the totals that were in the top ten percent of the 128-winter season records. These states were the recipients of nearly one dozen winter storms that were accompanied by atmospheric rivers that carried abundant quantities of water vapor and hydrometeors in relatively narrow and long plumes from the humid regions of the tropical and subtropical Pacific Ocean. Wisconsin had a statewide winter total that was the highest in its entire 128-winter season record, followed by Minnesota with its third highest winter precipitation total and Iowa with having the fifth-most winter precipitation. Twenty additional states scattered across the "Lower 48" had statewide winter precipitation totals that were withing the above-average category. Conversely, only three states in the Northwest (Idaho, Oregon and Washington) and Florida in the Southeast had below-average winter precipitation. The remaining fifteen states had near-average statewide precipitation totals for winter 2022/23.
    Alaska had a 2022-23 winter statewide average precipitation total of 8.61 inches, which was 0.46 inches above the 1925-2000 average; consequently, this just-concluded winter was the 39th wettest in 98 winters on record.
• Significant and extreme climate events for February and meteorological winter -- A map entitled "U.S. Selected Significant Climate Anomalies and Events for February and Winter 2023" graphically summarizes several significant weather and climate events that occurred across all 50 states and Puerto Rico this past month. NOTE: A description is provided of the climatological rankings employed by NCEI for their monthly and seasonal maps. [NOAA/NCEI]
  
• February national drought report -- NCEI has posted its February 2023 drought report online. Using the Palmer Drought Severity Index as an indicator, approximately eight percent of the contiguous United States experienced severe to extreme drought conditions at the end of February, while four percent of the area had severely to extremely wet conditions.
• Western snow drought update for March 2023 is released -- NOAA's National Integrated Drought Information System (NIDIS) issued its Snow Drought Status Update for March 2023. This report is for the water year 2023 that began 1 October 2022 and runs through 30 September 2023. Maps are featured depicting the snowpack accumulation across the Western U.S., where the snow accumulated on the numerous mountain ranges provides water to residents, agriculture and industry throughout the year. According to NIDIS, a snow drought "is defined as period of abnormally low snowpack for the time of year, reflecting either below-normal cold-season precipitation (dry snow drought) or a lack of snow accumulation despite near-normal precipitation (warm snow drought)."
  According to this current Snow Drought Status Update, those automated SNOTEL stations that measure snow water equivalent (SWE) in the snowpack across remote mountain locations in California, Nevada, Utah, Colorado, Wyoming and Arizona continued to grow as of the mid-March date. SNOTEL sites in California, Nevada. Arizona and Utah had SWE levels that ranged from 150 to over 200 percent of their 1991-2020 median values. These stations are in the Sierra Nevada, Great Basin, and Colorado River Basin. and they have been benefiting from the numerous atmospheric rivers that have transported abundant quantities of tropical and subtropical water vapor from the Pacific into California and other locations across the region. However, SNOTEL stations located farther to the north and east across Washington, Oregon, Idaho and Montana had SWE values that ranged between 80 and 130 percent of normal as the atmospheric rivers have been to the south. In addition, areas of snow drought remain in mid-March along the east-facing slopes of the southern Rocky Mountains and adjacent high Plains, with SWE values across Colorado and New Mexico ranging between 75 and 110 percent of normal, a few sites in the Sangre de Cristo Mountains in southern Colorado and northern New Mexico had SWE values that were in the 10th to 20th percentile for the period of record. In Alaska, many of the SNOTEL sites across south central and southeastern sections of the state had SWE values that were above normal in mid-March; however, some sites on the Kenai Peninsula, the North Slope, and the southwest coast west of Bethel, had below normal SWE values. [U.S. Drought Portal]
• New Seasonal (3-month) Climate Outlooks released for spring -- Late last week forecasters at NOAA's Climate Prediction Center (CPC) released their Three-Month (Seasonal) Climate Outlooks for the three-months running from April through June 2023, which contains the last two months of Northern Hemisphere meteorological spring and the first month of meteorological summer. A 40-second video (no sound) entitled "NOAA's outlook for spring climate, drought, and flood risk in 2023" is available where a series of outlook maps summarizes the drought, flood, precipitation, and temperature outlooks for April-June 2023. [NOAA News] or [NOAA Climate.gov News] Specific details include:
• Temperature and precipitation outlooks -- According to their temperature outlook, nearly one half of the 48 contiguous United States should experience a good to high probability of above average spring and early summer temperatures. This region would run across the southern and eastern states, with the highest probability of a warm spring running from Texas eastward along the Gulf of Mexico coast to the Florida Peninsula and northward along the Atlantic Seaboard to southern New England. On the other hand, sections of the northern Plains, the Upper Midwest and the Intermountain West could have a better than even chance of experiencing cooler than average spring conditions. The region could have the highest chance of a cool spring is centered on North Dakota and northwestern Minnesota. The remainder of the "Lower 48" could have essentially "Equal Chances" of above-average, below-average or near-average temperatures for the months of April through June. This region would extend along the West Coast, as well as eastward across the northern and central Rockies and the central Plains into the western Great Lakes. The northern sections of Alaska generally from the Brooks Range to the Arctic Ocean could experience a relatively high probability of a warmer than average spring. The remainder of the 49th State would have "Equal Chances" of below, above or near average temperatures.
  The CPC precipitation outlook calls for better than even chances of drier than average spring and early summer conditions for a large swath of the western contiguous states, extending from the Pacific Northwest eastward across the Rockies and southward across the Plains to the western Gulf Coast. Two regions with the highest probability of a dry spring would be centered over the Great Basin of Utah and Nevada and across the southern Plains centered on the Panhandles of Texas and Oklahoma. On the other hand, the highest probabilities of wet conditions over the next three months would be limited to those sections of the Midwest and neighboring states bordering the central and eastern Great Lakes. The remainder of the coterminous states should have equal chances of below-, near- and above-average spring precipitation, especially over the northern tier of states, the Mississippi Valley and the Eastern Seaboard. Sections of western Alaska could have above average precipitation, especially on the Seward Peninsula and along the Bering and Chukchi Seas. The remainder of the 49th State could have "Equal Chances" of below-, above- or near-average precipitation. The entire 50th State of Hawaii could have wet weather over the next three months.
  A summary of the prognostic discussion of the outlook for non-technical users is available from CPC. Since La Niña has effectively ended in terms of the oceanic component to the tropical Pacific basin as of the start of March, its contributions to the outlook have been minimized. However, the atmospheric component has been slower to change, meaning some La Niña impacts may still continue into April. expected to continue through the remainder of boreal meteorological spring and into Northern Hemisphere summer, with a nearly equal chance of transitioning into ENSO-neutral conditions or remaining a La Niña. More attention was given by CPC toward current temperature trends, anomalous soil moisture, snow cover and snow depth conditions as factors in the preparation of the seasonal temperature and precipitation outlooks, along with numerical and statistical model output from various models.
  A description is also provided as how to read these 3-class, 3-month Outlook maps.
• Seasonal Drought Outlook released -- The CPC's US Seasonal Drought Outlook was released for late March through June 2023 that indicates a continuation or expansion of the current drought conditions across areas of southern and central Plains, along with sections of the interior Northwest, According to last week's U.S. Drought Monitor map (using drought data as of 14 March 2023) the southern and central Plains are experiencing severe (D3) to exceptional (D4) drought, while abnormally dry (D0) to D3 conditions are found across the interior Northwest. On the other hand, areas across the Great Basin (Nevada and Utah), northern California along with the Plains extending from central Oklahoma northward to the Dakotas and eastern Montana currently experiencing abnormally dry or moderate drought conditions should see their drought conditions either improve or be eliminated. The Florida Peninsula and Gulf Coast regions currently under D0 through D2 drought conditions should also see an elimination of the drought. Note: a Seasonal Drought Outlook Discussion is included describing the forecasters' confidence.
• Spring flood outlook for nation -- Forecasters with the National Weather Service's Office of Water Prediction issued their "2023 U.S. Spring Flood Outlook" that foresees flood risks for this spring ranging from a minor to major across southeastern, central and southwestern sections of the contiguous U.S.
  The above normal snowpack across sections of the northern Plains and Upper Midwest has led to a major flooding potential for portions of the Upper and mid-Mississippi River. However, moderate flooding is expected along the Red River of the North in North Dakota and the James River in South Dakota. Some minor flooding could occur in the region around the western Great Lakes. Widespread flooding has been occurring throughout California, including ongoing minor to moderate river flooding because of the numerous atmospheric river events that have come onshore along the southern and central California coasts, bringing significant rain events to low elevations and major snowfall at higher elevations. Furthermore, near record snowpacks in the Sierras and above normal snowpacks in the Great Basin, and portions of the Central Rockies should lead to the continued potential for minor to moderate flooding for higher elevation basins in those areas as well as portions of the Upper Snake River when melting begins. Some minor flooding is possible in the Ohio, Cumberland, and Tennessee Valleys across the Mid-South and Southeast.
  Alaska could have near normal ice breakup and flood potential this spring. However, flood potential is expected to be above normal for the Upper Yukon, Upper Tanana, and portions of the Copper River basins.
• 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]