Feb 20-24, 2023 Weather & Climate News

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Feb 20, 2023, 6:21:57 AM2/20/23

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Note: This weekly summary will resume on/around March 13, 2023.

(Source: AMS, 2/20/23)

WEEKLY WEATHER AND CLIMATE NEWS 20-24 February 2023 Items of Interest:

Becoming AWARE -- During this coming week (19-25 February 2023), Louisiana and Tennessee have scheduled its Severe Weather Awareness Week. 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. Other states farther to the north will be observing their Severe Weather Awareness weeks in the next ten weeks.
Worldwide GLOBE at Night 2023 Campaign for February concludes -- The second in a series of twelve GLOBE at Night citizen-science campaigns for the calendar year 2023 continues through Tuesday, 21 February. 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 Orion and Canis Major 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 third series in the 2023 GLOBE campaign is scheduled for 13-22 March. [GLOBE at Night]
Mardi Gras climatology -- Since Ash Wednesday, the beginning of the 40-day Lenten season observed by Christians, will begin on Wednesday (22 February), the day before (Tuesday, 21 February) is a day of celebration in many locations that is variously called Mardi Gras (French for Fat Tuesday) or Shrove Tuesday. One of the more famous Mardi Gras celebrations occurs each year in New Orleans, LA. . Since Mardi Gras is 46 days before the moveable feast of Easter, it can be any Tuesday between 3 February and 9 March. The National Weather Service Forecast Office at New Orleans/Baton Rouge has a 2023 Mardi Gras Climatology that provides the normal temperatures and precipitation along with extremes for New Orleans during the Mardi Gras week prior to Ash Wednesday. Some additional statistics involving a listing of the weather history for each Mardi Gras in New Orleans extending back to 1874 are provided.
Watching for high ocean tides along nation's coasts during this week -- According to the NOAA National Ocean Service's High Tide Bulletin for Winter 2022, higher than average astronomical tides have developed along the U.S. coasts as early as last Saturday (18 February) along the U.S. Pacific Coast, Alaska and the U.S. Pacific Islands and will continue through this upcoming week. The exact days when these higher than average tides are to be expected, as well as the length of the interval will depend upon the region. These high tides along the U.S. Pacific Coast (California northward to Washington state) should run through Tuesday (21 February), the coasts of Hawaii and the U.S. Pacific Islands (Guam, American Samoa, Midway, Kwajalein and Wake Island) through Thursday (the 23rd) and Alaska until Saturday (the 25th). After starting on Sunday (the 19th), higher than average tides should be expected along the U.S. Atlantic Coasts (from Virginia northward to Maine) through Thursday. Some minor coastal flooding could result along any of these coasts. In addition to tides that are higher than normal high astronomical tides during this week, lower than normal low tides can be encountered each day. The nation's Gulf of Mexico coast and the Southeast Atlantic coast should not be significantly impacted by high ocean tides this month.
These above- and below-average tides are known as a perigean spring tides, caused by the occurrence of lunar perigee (when the Moon is closest to Earth) and a new or full moon. Lunar perigee occurred early Sunday morning (19 February at 09:07 Z or 4:07 AM EST, 3:07 AM CST, etc.), which was only 22 hours before passage of new moon (at 07:09 Z on Monday, the 20th). [NOAA National Ocean Service News]
State climate summaries are available -- NOAA has a set of 52 climate summaries that includes one for each state, plus Puerto Rico and the U.S. Virgin Islands. These State Climate Summaries were developed in partnership with the Cooperative Institute for Satellite Earth System Studies (CISESS), six Regional Climate Centers (RCCs), and individual state climatologists. Dated 2022, these summaries include up-to-date, local perspectives on climate are provided in each state summary, spelling out recent local conditions for each state and providing insights about the stateâ€™s climate outlook based on historical trends. Many of the summaries for the coastal states have projections of changes in coastal flooding or high tide events associated with projected changes in global sea level. An interactive website hosted by CISESS provides easy access to the information for each state, along with additional details common to the project. [NOAA NCEI News]
Editor's note: These current 2022 State Climate Summaries should be viewed as a reputable and up-to-date resource for anyone wanting formation about the climate in any U.S. state (or territory) that includes the current climate, past climate trends and future climate outlooks. This editor encourages exploration of this resource. EJH

Weather and Climate News Items:

Eye on the tropics --- During the last week, two tropical cyclones (atmospheric low pressure systems such as tropical storms or hurricanes that form over tropical oceans) were found over the waters of the South Indian Ocean and South Pacific basins:
- In the South Indian Ocean basin (that includes the South-West Indian Ocean south of the Equator from Africa's east coast to the 90-degrees East meridian and the Australian region from 90 degrees East to Australia --
  - Tropical Cyclone Freddy was a category 3 tropical cyclone (on the Saffir-Simpson Scale) as it headed west across the waters of the South Indian Ocean last Monday. Maximum sustained near-surface winds were estimated to have been 115 mph winds as it was 185 miles to the south of Cocos Island. During the remainder of this past week, Freddy took a track that was generally toward the west-southwest, with some changes in intensity as determined by changes in its estimated sustained wind speeds. On late Wednesday, Freddy reached its peak intensity with sustained winds hitting 155 mph, just shy of reaching category 5 status. As of early this Monday, Tropical Cyclone Freddy was continuing to track toward the west-southwest approximately 260 miles east-northeast of Port Louis, Mauritius. At the time, Freddy was still a category 4 tropical cyclone with 150-mph sustained winds. Freddy was forecast to continue on its path to the west-southwest and pass to the north of Mauritius before making landfall along the eastern coast of Madagascar on Wednesday. As it travels on Monday and Tuesday, Freddy should weaken and could make landfall on Madagascar as strong as a category 3 system. Additional weakening should occur with Freddy weakening to a tropical storm as it crosses Madagascar due to interaction with the island's high terrain. After crossing the island, Freddy could re-intensify to a category 1 tropical cyclone as it travels across the Mozambique Channel, before reaching the coast of Mozambique by this coming Friday.
- In the western South Pacific basin (located off eastern coast of Australia, running from a longitude of 160 degrees East eastward to the 120-degrees West meridian) --
  - Tropical Cyclone Gabrielle had become a category 2 tropical cyclone (on the Saffir-Simpson Scale) before the start of this past week as it traveled to the southeast as it was heading for New Zealand's North Island. However, Gabrielle had transitioned to a strong subtropical low as it approached the island. Although it had become a subtropical cyclone, Gabrielle impacted North Island with torrential rains and strong winds through the much of this past week. A visible satellite image obtained last Tuesday from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NASA-NOAA Suomi NPP satellite shows clouds surrounding Cyclone Gabrielle as it was centered near the North Island. One should note that the cloud swirl is in a clockwise direction because the cyclone was in the Southern Hemisphere, rather than as a counterclockwise direction as found associated with Northern Hemisphere cyclones.
Review of national weather and climate for January 2023 -- Scientists at NOAA's National Centers for Environmental Information (NCEI) recently reported on their analysis of preliminary weather data collected from across the nation during the month of January 2023. [NOAA/NCEI Monthly Report] They found:
- Temperature -- The nationwide average temperature for the contiguous United States for the month of January 2023 was 35.2 degrees Fahrenheit, which was 5.1 Fahrenheit degrees above the 20th century (1901-2000) average. This national average monthly temperature for last month was the sixth highest January average temperature since comprehensive national climate records began in 1895. The nationally averaged maximum temperature (daytime highs) for January 2023 was 44.5 degrees Fahrenheit, which was the 12th highest January average daily maximum reading in the 129-year record, while the nationally averaged January 2023 minimum temperature (overnight lows) was 25.8 degrees Fahrenheit, which tied January 1990 as the fourth highest January average minimum temperature.
  The majority of the contiguous states (39) reported January monthly average temperatures that were in their state's upper-third of its period of record, or equivalently in the "above-" to "much-above-" average temperature rankings on the map; (see the explanation to the ranking scheme provided by NCEI at https://www.ncei.noaa.gov/access/monitoring/dyk/ranking-definition). Seven Northeastern states (the six New England States and New Jersey) experienced record high January monthly average temperatures. In addition, eighteen states located primarily to the east of the Mississippi had January 2023 statewide average temperatures that were in the top ten of their respective state's period of record. On the other hand, nine states located mainly in the southwestern quadrant of the "Lower 48 States" had January average temperatures that were close to the long-term average.
  The January 2023 statewide average temperature for Alaska was 10.9 degrees Fahrenheit, with was the 13th highest January temperature in Alaska's statewide record that goes back to 1925.
- Precipitation -- The scientists found that last month was wetter than average, as the nationwide averaged January 2023 precipitation was 2.85 inches or 0.54 inches above the 20th century average; thus, last month had the 18th most precipitation in January across the contiguous U.S. in 129 years.
  The majority (35) of the contiguous states reported above- to much-above-average statewide precipitation amounts this past January. Six states running from California eastward to Iowa had statewide precipitation amounts that ranked within the top 13 in their state's January records. The atmospheric rivers that came on shore along the Pacific coast in January contributed to these high totals. Five other states in the east, (Georgia and the New England States of Maine, Massachusetts, New Hampshire and Rhode Island) also had much-above-average statewide precipitation. Conversely, eight states scattered across the Northwest and Middle Atlantic had statewide precipitation amounts that ranked within the lowest thirty-four January precipitation amounts in their respective state records. North Dakota had its thirteenth driest January precipitation totals in state history. The remaining four states scattered across the "Lower 48" had near-average precipitation totals.
  The state of Alaska had above average precipitation, with a statewide January average of 3.06 inches, which was 0.33 inches above the 1925-2000 average and 39th largest in 99 years. [NCEI State of the Climate]
- January Snow Cover -- The January 2023 snow cover across the coterminous United States was the 24th highest in the 57-year period of satellite surveillance record, according to the Rutgers Global Snow Lab January 2023 National Snow and Ice Report.
- January significant and extreme climate events -- A map entitled "U.S. Selected Significant Climate Anomalies and Events for January 2023" graphically summarizes several significant weather and climate events that occurred across all 50 states and Puerto Rico during this past January.
- January national drought report -- NCEI has posted its January 2022 drought report online. Using the Palmer Drought Severity Index as an indicator, approximately nine percent of the contiguous United States experienced severe to extreme drought conditions at the end of January, while two percent of the area had severely to extremely wet conditions.
- January near-surface wind data -- A portfolio of maps have been produced by NCEI showing the monthly mean wind speeds at 10-m (standard anemometer) height for the month of January 2023 across the contiguous U.S, along with the corresponding mean wind speed anomaly from the 1991-2020 mean for January. During this past month, near-surface winds across large sections of the contiguous U.S. were lower than average. These lower-than average winds speeds (indicated by the blue shading on the anomaly map) were across a region that stretched eastward from the east-facing slopes of the northern and central Rockies across the northern Plains and Great Lakes to the Atlantic Coast. However, above-average wind speeds (as indicated by the red colors on the anomaly map), were detected across along the Pacific Coast, the Southwest, the southern Rockies, and southern Plains to the lower Mississippi Valley. The strongest winds were found off the central California Coast, west of San Francisco Bay (where deep red colors are shown).
  A set of four additional maps showing the vector components of the winds in terms of the west-to-east or U-component (along a parallel of latitude) and the other south-to-north or V-component (essentially along a meridian of longitude) are provided as monthly January 2023 means and anomalies from the 1991-2020 normal are provided. Positive west (or u-wind component) anomalies (shaded in red) were found across the southern tier of states stretching from the waters of the North Pacific offshore of southern California eastward to the wasters of the North Atlantic offshore of Florida, Georgia and the Carolinas. Negative u-or west wind anomalies (blue shading) indicating weaker west wind components (or even components from the east as found along coastal regions of the Pacific Northwest) were found across the remainder of the "Lower 48" States. Positive south (or v-wind component) anomalies (shaded in red) were found across the southern tier of states running from southern California to the Atlantic coast in the Southeast, which indicates stronger southerly wind components. Stronger than average southerly winds were reported across the Southwest, the Gulf Coast States and the North Atlantic well offshore of New England. Conversely, the interior Northwest, the central Plains, Midwest and the eastern Great Lakes and St. Lawrence Valley had negative south wind anomalies (in blue), which indicated either weaker southerly wind components or northerly wind components. [NOAA/NCEI Wind Climatology]
Western snow drought update for February 2023 is released -- NOAA's National Integrated Drought Information System (NIDIS) issued its Snow Drought Status Update for February 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 mountains 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)." At the start of this meteorological winter (on 1 December 2022), cold weather and snow across large sections of the West resulted in essentially all of California, Nevada, and Oregon, along with parts of Washington, Idaho, Montana, Utah, and Arizona to have greater than 150 percent of normal snow water equivalent. A series of cold winter storms from off the Gulf of Alaska and the North Pacific Ocean in the form of strong atmospheric rivers reached the Pacific Northwest and into California, resulting in an abundant snowpack across the mountains of the Northwest. On the other hand, New Mexico, southeastern Arizona and parts of southern Colorado remained in snow drought conditions. During January 2023, a minor expansion of snow drought occurred as small-to-moderate storms containing less atmospheric humidity crossed the West.
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 had record high or second highest for the mid-February date. SNOTEL sites in California, Nevada and Utah had SWE levels that ranged from 150 to over 200 percent of their 1991-2020 median values. Farther to the north and east, SNOTEL stations across Washington, Oregon, Idaho and Montana had SWE values that ranged between 80 and 120 percent of normal, down slightly from one month earlier. Areas of snow drought remain in mid-February 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 45-60 percent of normal for the date. 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-February; however, some sites on the Kenai Peninsula, and the south-facing slopes of the Alaska and Brooks Ranges had below normal SWE values. [U.S. Drought Portal]
Seasonal (3-month) Seasonal weather outlook released for meteorological spring -- Late last week, forecasters at the NOAA Climate Prediction Center (CPC) released their new national Seasonal Outlook for the next three months that consists of meteorological spring 2023 in the Northern Hemisphere (March-May). Specific details of their outlooks include:
- Temperature and precipitation outlooks -- According to their temperature outlook, slightly more than half of the land area comprising the contiguous U.S. should experience a high chance of above-average temperatures for Spring 2023. This region runs from the Lower Colorado Basin in southern California eastward across the southern tier of states to the Atlantic Seaboard and then northward along the East Coast to northern Maine. The region with the greatest probability of unseasonably warm weather should be found along the Rio Grande Valley in the vicinity of the Big Bend area of Texas. On the other hand, sections of the Northwest could see a good chance for below-average spring temperatures, primarily stretching from the Pacific Northwest (Washington state and northern Oregon) along the U.S.-Canadian border to northwestern Minnesota. This region constitutes nearly ten percent of the geographic area of the "Lower 48" States. The region that appears to have the highest probability of a cold spring would be from the Idaho Panhandle across northern Montana into northwestern North Dakota. The outlook indicates that the remainder of the "Lower 48 States" stretching from California northward and eastward across the Intermountain West, the Rockies and the Plains to the Western Great Lakes should have nearly "equal chances" of below-, near- or above-average temperatures (identified by the "EC" label). The southeastern sections of Alaska appear to have a high chance of a cold spring, with the highest confidence for below average temperatures found across the southeastern Panhandle. Northern and western sections of Alaska including the Alaska Peninsula and the Aleutian Island chain would have a spring outlook of a warmer than average spring. The northwest coast along the Chukchi Sea could have the highest probability of warm conditions. The remainder of the 49th State, which would include in the southwest, along with western and northern Alaska appear to have "equal chances" of below-, near- or above-average spring temperatures.
  Their precipitation outlook indicates that the Southwest and sections of the Southeast stand a better than even chance for below average precipitation during Spring 2023. The region with the highest chances of a dry spring would be centered across the Four Corners States (Arizona, Utah, Colorado and New Mexico). The Southeast, which includes the Florida Peninsula, appears to be leaning toward dry conditions. Conversely, sections of the Midwest and Middle Atlantic States should expect a wetter than average spring. This region that could be likely for wet conditions is centered on the central Great Lakes and Ohio Valley. The remainder of the "Lower 48 States" are considered to have essentially equal chances of below-, near- or above-average precipitation for meteorological spring. Southeast Alaska, including the Panhandle, could have a dry spring, while western Alaska could have above average precipitation over the next three months.
  A summary of the prognostic discussion of the 3-month outlook for non-technical users is available from CPC. These forecasts were based in part on the continuation of the current La Niña conditions especially in terms of the atmospheric circulations through most of meteorological spring, in the Northern Hemisphere before making an anticipated transition to ENSO-neutral conditions by early meteorological summer. Therefore, the spring temperature and precipitation outlook patterns continue to exhibit a typical La Niña pattern. Other factors considered include temperature, snow pack extent and soil moisture. The forecasters' confidence on their outlook discussion for individual regions of the nation is given. A description is also provided as how to read these 3-class, 3-month Outlook maps.
- Seasonal Drought Outlook -- The forecasters at NOAA's Climate Prediction Center also released their US Seasonal Drought Outlook last week that would run from mid-February through May 2023. Their CPC outlook shows that the current drought conditions found across large sections of the West should continue to experience drought conditions, with a few exceptions; last week's U.S. Drought Monitor map (released on 16 February 2023) provides the current extent and intensity of the drought across the nation. Drought was expected to remain or expand across sections of the Southwest, especially along the southern and central Plains just to the east of the Rockies, running from the Rio Grande Valley of southern Texas and eastern New Mexico northward to the Nebraska Panhandle and southeast Wyoming. Farther to the west, drought should also continue across a large section of the Great Basin in Utah and Nevada along with across the southern half of California. Sections of the Southeast that include the Florida Peninsula and coastal sections of Georgia and South Carolina also could see intensification of drought conditions. Improvement of current drought conditions could occur across large sections of the interior Northwest (Oregon), the northern Rockies and a broad area of the Plains extending from the Dakotas southward to Oklahoma. Several widely scattered areas in the Midwest currently under abnormally dry and moderate drought could have marked improvement in the drought conditions or removal from drought status.
  Note: a Seasonal Drought Outlook Discussion is included describing the forecasters' confidence.
Ice cover on North America's Great Lakes reaches a record low -- At the start of last week, the combined ice cover on all of the Great Lakes had dipped to just 7.5 percent, which represents a record low coverage for this time of year. The record is based on satellite-derived Great Lakes ice data running from 1973 to 2022. Typically, ice cover on all five Great Lakes reaches a peak coverage in late February that has an average of 41 percent. The previous record low coverage for this time of year was 8.5 percent that was reached in 2012. As of last Monday, Lake Superior had a 6-percent ice cover; Lake Michigan had 8 percent; Lake Huron had 15 percent; Lake Erie had 0.9 percent and Lake Ontario had 4 percent. This year's lowest ice cover on record for the Great Lakes appears to be consequence of the relatively mild weather that has been experienced for most of this winter across the Great Lakes. Over the last 30-days, temperatures across the Great Lakes ranged between 2 and 8 Fahrenheit degrees above the 1991-2020 averages. [Minnesota Public Radio News]
A natural-color satellite image produced last Monday from data collected by the Visible Infrared Imaging Radiometer Suite (VIIRS) on board the polar-orbiting NOAA-20 satellite clearly shows the lack of significant lake ice on all the lakes, with the exception of the eastern half of Lake Ontario (that is located off the right edge of the photo). Snow-covered lake ice can be detected along some of the shorelines and in several of the bays, most notably Saginaw Bay in Lower Michigan along Lake Huron and the bay of Green Bay in northeastern Wisconsin off Lake Michigan. The marble-like appearance of the relatively ice-free Lake Erie is due to lake sediments that have been placed into suspension by passing storms. [NASA Earth Observatory]
A discussion of the historical trends in lake ice cover since 1973, the role of lake surface temperature, the impacts of reduced ice cover and the ecological implications of smaller ice cover has been prepared by Great Lakes Integrated Sciences and Assessments (GLISA). [Climate Impacts for Great Lakes Ice Coverage GLISA]
Daily updates of lake ice and surface water temperature are available in tabular and graphical format for each of the Great Lakes. [NOAA Coast Watch Great Lakes]
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]