DISCUSSION: Winter is in full swing in the Northern Hemisphere, and while much of the United States mainland is experiencing cold temperatures, or winter storms which encompass snow, there are warm locations within the U.S. that are experiencing winter phenomena not known to its mainland counterparts. Hawaii, the 50th state, experiences 11 of the world’s 13 climate zones, often experiencing various weather on several parts of one island even within several miles. Of notable recent winter conditions in Hawaii, was the widespread impacts of a Kona low.
As recent as the week of February 9th, 2019, did the state of Hawaii feel the effects of a Kona low in the area. Typically, island weather is dominated by the Northeast trade wind flow, at times bringing wet conditions to windward and mauka (mountain) locations of the island chain. A Kona low, Kona in the Hawaiian language having various interpretations, in this context could be determined as “leeward or dry side of the island,” is primarily a subtropical cyclone (counterclockwise inward flow) with a southerly wind component in this case. Often Kona lows bring unprecedented winds, large surf, heavy rains, and other hazardous conditions to the islands. During this most recent storm, surf brought nearly 30-40-foot faces, winds in excess of 45 mph and of note a 191-mph wind reading at the top of Mauna Kea, in addition to snow seen on Mauna Kea, Mauna Loa (on Hawai’i) and Haleakala on Maui, an astounding happenstance on Maui as elevations of snowfall around 6000 feet.
Kona lows while they often disturb the trade wind flow, bringing cooler temperatures, are not uncommon outside of summer, often seen between fall and spring in the Pacific. There is a potential for the low to be subtropical or tropical, often a colder core of air than a tropical storm, mass disorganizations and in general characteristics of several types of systems. While winter is not quite over yet for the islands, chances so see such storms may decrease as temperatures begin to warm waters and the atmosphere in the Pacific region, as we move into spring and summer seasons.
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© 2019 Meteorologist Jessica Olsen
Video: Honolulu, Hawai'i, Courtesy: Meteorologist Jessica Olsen
DISCUSSION: During the heart of any given Winter-time season, there can periodically be rounds of particularly cold weather which impact various parts of North America, Europe and beyond. Depending on the exact severity of any given cold air intrusion, air temperatures can sometimes either fall slightly below the freezing mark (i.e., 32 ° Fahrenheit or 0 ° Celsius) or substantially below the freezing mark to even dangerous levels. One such example of this is what unfolded across a good portion of the north-central and northeastern United States within the past 10 days as a “lobe” of a true Arctic mass associated with the highly-touted “Polar Vortex” planetary circulation feature broke off and descended into the mid-latitudes (i.e., regions which are located between 30°N and 60°N latitude which include but are not limited to a good portion of North America and Europe). When this frigid air mass made its way further into the central and eastern United States (i.e., even at a somewhat modified severity in terms of the extent of the cold air temperatures being measured), this paved the way for some neat associated Winter weather science education opportunities.
One such example of a neat winter weather science education moment was a “case and point” example of how supercooled and fully purified water in a bottle can freeze on command after being left outside during a single overnight period. To be more specific, when a bottle of undisturbed and fully purified water is left outside in very cold (and well-below freezing temperatures) for several hours or even overnight, there is often no freezing which occurs. As also explained by ABC Kansas City Meteorologist Nick Bender, freezing of water molecules within some given confined space requires other a bubble created from some given physical disturbance to set off a chain reaction and/or some given particulate to help initiate the freezing process to get underway at a molecular level.
Thus, this winter weather science education experiment example just goes to show that even during the coldest parts of the year, there can always be a great opportunity to still learn something about how physics affects the natural world. So, the next time you, your friends, and/or your family are lucky or unlucky enough (depending on how you look at it from your perspective) to experience the full-force of a true Arctic air mass intrusion, definitely be sure to bundle up in warm layers and give this simple experiment a try to see for yourself.
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© 2019 Meteorologist Jordan Rabinowitz