Cyclone Cook is currently aiming towards New Zealand, with 30-40 kt winds along the East Coast of the North Island and off the East Coast of the South Island. Winds will become more northerly as the system continues to slide southward through the remainder Friday and into early Saturday [local NZ time]. Winds in excess of 20kts will remain along the North Island through Saturday afternoon [local NZ time], subsiding below 15 kts by Sunday evening/early Monday [local NZ time]
Observe the moisture flow in the 1000-500 mb relative humidity [RH] field.
Cool wraparound feature, as the moisture gets transported on the winds toward the departed NE low on the right hand side of the frame. Also notice the connective feature of the departed low tapping into the moisture pool from the Gulf of Mexico [GOMEX].
West coast also seeing an increase in available atmospheric moisture.
Yes, it’s “Daylight Saving Time” (DST), without the extra “s” at the end of “saving”. So now that we’ve got this common mistake righted, back to business!
“Fall Back” and “Spring Forward”: Remember this so-called helpful pneumonic? It was devised to help one remember how to alter household “timekeepers” by an hour in order to keep you astronomically synchronized. In short, it was designed to maximize “daytime” hours by capitalizing on the sun’s generosity, which is lavish in the summer and frugal in the winter. Calendar wise, daylight saving time runs in and around April through October, while November through April is known as “standard time. For 2017 in the Northern Hemisphere, DST will begin Sunday, March 12th, and end Sunday, November 5th. The inverse holds true for DST in the Southern Hemisphere.
With the idea borrowed from an Old English proverb, “Early to Bed, early to rise, makes a man healthy, wealthy, and wise”, Benjamin Franklin tossed around the idea in the late 18th century as a means to save on candle usage during the earlier sundown. He figured, why not start the day an hour earlier to use the light while it was in place, thereby reducing the amount of candles burned. It wasn’t until the late 19th century that the idea was officially proposed by New Zealander George Hudson, with the idea of giving people more sunlight in the late spring and summer, when it could be best enjoyed. While the idea was out in the open, it was not favored. Germany was actually the first country to adopt the process of sommerzeit (literal German for summertime) in the early 20th century. This was done as a means to “conserve energy” by keeping people outdoors longer. The practice of DST came and went over the earlier part of the 20th century but eventually made a necessary appearance during a global petroleum shortage in the 1970’s brought on by an OAPEC oil embargo. Higher prices of oil per barrel forced a smart economic resolution of reducing oil dependence and relying on the natural resource of the sun’s light. Fast forward to today, with the innovation of smarter energy practices and work hours which know no boundaries, not every country utilizes DST.
We know the sun doesn’t change its output, so exactly why does the change in the amount of daylight occur? In an earlier post about spring, we discussed the Earth’s tilt as being the primary reason behind the seasons. This tilt, in tandem with the Earth’s position around the sun, determines how much daylight each hemisphere receives. Essentially, the amount of energy from the sun doesn’t change, but our ability to experience it, as a result of our position around the sun, is what changes.
Spring is the transitional season where the Earth changes hands from winter to summer; when the planet begins to learn towards the sun. Along those same lines, autumn is the transitional season between summer and winter, when the Earth begins the process of tilting away from the sun. This slow changing tilt towards (away) from the sun yields longer (shorter) amounts of time that a given hemisphere can receive sunlight. The special day during which the Earth receives its maximum amount of sunlight is known as the “Summer Solstice”, which occurs on June 21 in the Northern Hemisphere and on December 22 in the Summer Hemisphere.
Moving the clock forward in March/April ultimately removes an hour of daylight as we approach spring and summer seasons, when we already get more sunlight. Conversely, moving the clock back an hour in November yields an additional hour of daylight, which becomes especially useful as we approach the fall and winter seasons when the amount of sunlight becomes less. At the expense of sounding like a financial planner, consider the loss of the hour in the spring, a short term investment strategy for the upcoming fall/winter season gain; save that sunlight for a “rainy” day!
With all of this in mind, the closer one is positioned to the Northern or South Pole, the more likely they are to utilize DST. So, if you don’t like the annual “give” or “take” activity that comes with this practice, its best avoided by moving closer to the tropics, where the length of day and night varies by small enough amounts to negate the need to alter the clocks!
And lastly, just a reminder, don’t forget to move your clocks forward by an hour on Sunday, March 12th. Ugh.
Daylight Savings Time: marked by “Spring Forward”, begins in March/April, and means you move the clock ahead an hour, therefore losing an hour. This is especially painful spring/summer seasons when you feel like you just got robbed!
Standard Time: marked by “Fall Back”, begins in November, and means you move the clock back by an hour, therefore gaining an hour. This is especially useful in the fall/winter seasons when a decrease in daylight occurs and you just want your hour back!
And no I don’t mean because I live in Florida, the land of hot or not-as-hot. You may have seen social Media sites buzzing with the mention of spring beginning today, March 01. Don’t worry, you’re not confused. There are indeed different definitions for spring, depending on whether or not you live in the world of meteorology or elsewhere in the “normal” world.
But before we separate the two, let’s take a step back and review the “anatomy” of the seasons.
Most people assume that the seasons are a result of the Earth’s distance from the Sun. While this initial thought is indeed intuitive, it’s counteracted with the fact that the Earth is actually closer to the Sun during the Northern Hemisphere Winter, and further from the Sun during the Northern Hemisphere Summer. Take a look!
The actual reasons we experience the seasons are a result of the Earth’s tilt. Summer and winter seasons yield the expected temperature extremes because the Earth’s tilt allows the Sun to unevenly concentrate its energy. Think of it this way: More of the solar “wealth” is given to one hemisphere [summer] at the expense of the other [winter].
Consequentially, spring and fall seasons are considered “transition seasons”; more specifically, where the position and tilt of the Earth occurs in such a way that the Sun’s energy is equally distributed between the Southern and Northern Hemisphere [spread the solar wealth, each hemisphere roughly gets the same].
So now that we share a same page of what seasons actually are, let’s get back to the original question: When does spring start? “Meteorological Winter” refers to the usual [climatological] coldest three months of the year, which means December, January, and February. Therefore “Meteorological Spring” begins right after, or today, March 1st!
The majority of the world goes by the astronomical seasons, which follows the Earth’s position around the Sun. The beginning of “Astronomical Spring”, also known as the “Vernal Equinox” requires the further understanding of what an equinox actually is.
Let’s take a quick science detour for more astronomical anatomy. The word “equinox” can be further dissected into its Latin roots; “equi” meaning “equal” and “nox” meaning “night”. Therefore, the definition of an equinox is when the day and night are of approximately equal times around the planet [roughly 12 hrs each, give or take several minutes depending on how close you live to the poles]. Going back to the “Vernal Equinox”, the position of the Earth around the sun during this time usually occurs between March 19 and March 21, and it kicks off the beginning of the calendar version of spring.
So “Happy Spring” to all my fellow scientists, and to the rest of you, catch you in a few weeks.
Meteorological Spring follows the average temperatures and begins on Mar 1.
Astronomical Spring follows the earth’s orbit around the sun and begins between Mar 19 and Mar 21