Weather: Snow And Not Snow At The Same Time

Hail in Hand (Image credit: Dr Barry Lynn)

Winds gusted to 120 km/h (75 mph) in Tel-Aviv last Thursday night/Friday morning and heavy rain fell in many locations. There was also plenty of thunder and lightning to light the sky. The strong thunderstorms produced lots of hail (some of which, as the photo shows, I gathered in my hand Friday morning). Despite the frequent rain, though, the accumulated amounts so far are still below normal for the season.

The strong thunderstorms occurred because of relatively cold levels in the upper atmosphere, with relatively warm and moist temperatures lower down. A radiosonde measurement taken at the IMS office in Bet-Degan near midnight Friday measured 1 C at 850 m, -10 C at 700 mb, and -27 C at 500 mb. When we discussed the upcoming situation last week, we mentioned that for snow to occur the temperatures at 850 mb would be below zero (ideally -1 C or lower) and -12 or lower at 700 mb. Combined with -27 C at 500 mb (which was colder than suggested by the forecast at the time), it would have been an ideal snow situation. It was not meant to be.

I am sure that there are plenty of folks who wondered why I mentioned the possibility of snow at all. For instance, at best there was a 40% chance that temperatures would be cold enough for snow. I might have easily just said that it was more likely that there would not be snow. However, it is my job to spice up the weather forecasts, to grab the reader's attention, and to build at least a bit of excitement.

There may be those who are disappointed that it didn't snow, and there might be those who are disappointed in me. Yet, what readers forget is that I am also disappointed the weather "didn't work out." I have feelings too -- I'm not just a reporter: I'm involved.

Anyway, the weather will warm up a bit on Sunday, but then a front will pass through Sunday night and we'll be headed to what could be a week of very wet and chilly weather. There will probably be two storms that arrive, the first on Tuesday and the next on Thursday or Friday. The first should bring rain, while the forecast indicates that there is a 25% chance of snow with the second.

Our snow chances may in fact be higher than in our last go around because this storm will be arriving from the north. This means that the low-level winds circulating around this storm will spend less time over the ocean, and have less time to warm enough to produce rain instead of snow. The "fly in the ointment" is that the cold air to our north is not as cold as typical for this time of year, so we may just get plain rain.

Jerusalem forecast (click here for updated national forecasts):

Image credit: The Jerusalem Herald

You may remember that it wasn't so long ago that we were quite worried that this winter would be another drought year. On the other hand, you may not have been worried about this, and this is what concerns me.

In fact, a lot of strange things have been happening to me lately. For instance, this morning I opened the door to our house and the power went off. The power came back, so I went out and opened the door again -- the power went off. I went to a neighbour, opened his door and the power came back on.

Of course, it was a coincidence, and one shouldn't make anything more of it.

But, this is not what I am speaking about. For a number of weeks, I have been arriving at the Bet-Knesset on Friday evening on-time, only to wait about 5 minutes for services to begin. But just recently, I arrived to the same Bet-Knesset five minutes late and the congregation was already half way through the Shabbat services. It was like I had come to a different Bet-Knesset.

A few days later, I lay down for a snooze, expecting to wake up about 12:30. I woke up a few times, and here are the times I saw on my watch: 12:23, 12:27, 12:18, 12:27, and 12:23. Weird.

Prior to the start of our rainy period it was very warm. My wife said to me: "I love these weather changes, as I can wear sandals at the end of December." I looked at her and wondered if this person was really my wife.

Two weeks ago was the Torah Portion "Va'era;" except for me, this happened two weeks in a row.

I think these strange occurrences can be explained by Quantum Mechanics -- how the world works on the scale of very small particles -- and what this implies for us. For instance, if one uses an electron gun to shoot electrons one at a time at a double slitted barrier, the electrons appear to pass through both slits at the same time, as implied by an unexpected wave interference pattern found on the detector on the other side. But, if we try to observe these single electrons passing through the slits, the interference pattern is eliminated and the pattern detected is instead what we would have expected (one electron passing through one of the slits one at a time).

The results is a conundrum. It appears that the essence of our world is a probability distribution, where the electron can be at both slits at the same time or some fraction of of the time, but when we try to observe what is happening, the electron behaves as we expect it to in our world.

This leads to strange situations. For instance, if we were to place a cat in a chamber with a radioactive trigger, quantum theory implies that it should be both dead and alive at the same time (since the decay of a radioactive particle from a single atom sometimes occurs and sometimes it doesn't -- but until we actually check, it is in both states). This is the conclusion of a thought experiment proposed by Erwin Schrodinger. The cat should remain thus until we (an observer) check to see what happened to the cat, and this is referred to as quantum indeterminacy or the observer's paradox.

To most people, this seems like an impossibility. The cat is either dead or alive but not both. One not so obvious solution to this problem is to simply accept the fact that in one "world" the cat is dead, while in the other the cat is alive, and that the observer (that's us) exist in two different realities. Or, to put it succinctly: there are two of us!

Taking this a step further, it means that when a card that is balanced on its edge falls in one direction, it also falls some percentage of the time (depending on its tilt) in the other direction, in another universe, and so-on. We the observer, however, do not know that these other universes exist or that (perhaps) they are being created all the time.

Except that I know -- because I have been moving between universes (even though this is suppose to be impossible) for the last month or so. The proof: I was living in a universe where it didn't rain and now it seems to rain all the time. There's also my wife... or at least someone’s wife.

And, there's probably a universe where it did snow, and snowed a lot, and I can't wait to get there.

Dr. Lynn is a lecturer at The Hebrew University of Jerusalem, Earth Sciences Department. He is also CEO of Weather It Is, LTD, a company that specializes in reducing weather risk.

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...הָרִימִי בַכֹּחַ קוֹלֵךְ מְבַשֶּׂרֶת יְרוּשָׁלִָם הָרִימִי אַל תִּירָאִי אִמְרִי לְעָרֵי יְהוּדָה הִנֵּה אֱלֹקֵיכֶם! (ישעיה  מ:ט)

...Raise your voice with strength, herald of Jerusalem; raise it, do not be afraid; say to the cities of Judah, "Here is your G-d!"

(Isaiah 40:9)

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