Sunday, March 17, 2019

Weather It Is (Winter's Revenge)

Good Afternoon:

When your own daughter turns against you, you know it is time to take down your barometer.

She is not the only one who asked me to end winter, reset the clock (if possible), and go forward to spring.

Based on conversations within our "Israel Winter Weather" group, I should mention that rainfall is much above normal this winter season, while temperatures are cumulatively below normal.  The combination has made for both a chilly and wet winter -- and led to rather disgruntled readers who don't remember what winters used to be like (there have been only two colder than normal winters since 2003-04, but this is probably the only wet one of the bunch).

Despite the chilly start to the week, temperatures should rise slowly over the next few days, but then they will start a a persistent decline towards the last week of the month.

When deciding what to write next, one should be very careful with ones words.  For instance, I won't mention that 10 cm of snow fell on March 18th, 1998 in Jerusalem, or that during March 26 & 27 1967 that there were snow accumulations from the north to the northern Negev.  One might also not mention that according to Uri Batz that there was 15 cm of snow in March 1874 and 20 cm in March 1880.  Also, I wouldn't dare to mention that 10 cm of snow fell in Jerusalem on March 16th, 1948.

I can mention that the last week of March should be a wet one with strong winds.  I won't mention that the chance of snow has risen from 15 to 25% from yesterday to today.  I won't mention this because climatologically speaking snow is very, very unlikely at this time of year.  Instead, what is more likely is strong winds, rain, and hail.

In general, there are both good and bad decisions made everyday.  Some are made out of hubris, and some are made out of greed. Others are made out of kindness. In fact, my decision to take care of a stray cat led indirectly (but it did) to my meeting my wife (who DID NOT like cats at that time).

Sometimes, decisions lead to tragic circumstances.  For instance, Air France Flight 447 crashed because of a number of bad decisions, but some were not connected to each other (https://www.popularmechanics.com/flight/a3115/what-really-happened-aboard-air-france-447-6611877/). For instance, the pilots chose incorrectly to not divert around a tropical storm (like most other flights that day).  Then, the radar on the plane was not tuned to the right mode, so they inadvertently entered an area of intense thunderstorms.  This led to the clogging of sensors that enabled the automatic pilot to function (based on measured air-speed).  Then, the "junior" co-pilot tried to take the plane over the area of bad weather, and both co-pilots initially ignored the warning that the plane's speed was decreasing enough to stall.  In the meantime, the captain had just previously left the cabin to take a nap, and when he returned he was not able to take effective action intime to save the plane.

However, one decision was previously made far from the airplane itself.  Airbus decided to link the "side sticks" that control the plane tilt (nose up or down).  This means that when one pilot tried to lower the nose of the plane to pick up speed he was unaware that the other was doing (incorrectly)  the opposite.  So, a decision made well prior to the crash of this plane in the end doomed the plane.

Of course, Boeing itself is in a lot of trouble for decisions made (both past and present) to design a plane and system that has already crashed two planes.  As noted, if one sensor measuring the pitch of the plane's nose malfunctions (https://www.nytimes.com/2019/03/15/business/boeing-ethiopian-crash.html) the automatic system can send the plane into a dive.  One wonders, as one commentator pointed out, "who" designed a critical system where just one of two sensors malfunctioning could doom the plane?

While it seems comparatively trivial, I could have decided not to mention that the forecasts are hinting at a possible late month (early Spring snow).  It can snow when it is climatologically unlikely (e.g., the super snowstorm of December 13, 2013).  But, the relatively strong spring sun means that we would need a very dark and persistent cloud cover, or a nighttime storm, to bring about any accumulation.  It all seems so unlikely, so why mention it?  It's in the forecast.  Ignoring the possible can have very dangerous consequences.

Barry Lynn

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.