Thursday, February 28, 2013

Weather It Is (The Drought Settles In)

Tonight and tomorrow a storm system will advance across the Mediterranean while a cold winter trough drops southward.  Temperatures will rise ahead of the low pressure, but it will remain breezy (but not as windy as today) for the Jerusalem Marathon.  Temperatures will rise even more on Shabbat as the low nears, and will feel quite warm for early March. 

The low and the trough will phase together on Sunday.  If this were "winter," this would be the perfect set up for a winter storm.  Yet, the atmosphere is not acting like winter, but more like the weather in late March when storms approach our area, but seem to lack good lifting and a good moisture source.  Hence, the storm approaches, and then sweeps quickly eastward with perhaps most of its rain shield remaining to our north.

Hence, the dry period of the last two weeks will likely become a dry period of three weeks, even though the weather won't feel like spring-- which is a bit strange.  We'll hope that a rainy period can return by mid-March.

To those running: good luck in the Marathon and Shabbat Shalom to all,

Barry Lynn

Monday, February 25, 2013

Weather It Is (Purim and Beyond)

Good Morning:

The weather looks pretty much now like it will look at the end of the week. Neither too warm nor too cool, with a few clouds here or there (depending on where you are).  In fact, the weather just might be perfect for the Jerusalem Marathon.

Yet, there are a few ensemble members that suggest that our sunny weather will be followed early next week by some rain, and there is even one (she, like a ship, perhaps?) who says it will be quite cold and snowy.  This isn't out of the question as the weather map shows extremely cold air over northern Europe and a series of low pressure areas moving across to the south that just might take a bite from this cold air.

We interviewed this ensemble member about her forecasts.  She said: "I know that my brothers and sisters (we're of the GFS family) are predicting pretty much springtime weather or springtime showers, but I'm different.  When they say up, I like to say down.  When they say sun, I like to say, well... I think it's going to snow and that winter will come roaring back." 

We were a little surprised to hear this, so we followed up.  "I've always been quite contrary," as if in explanation.  "In the summer time, for instance, I'll wear my fake fur coat even when its 35 degrees." When I looked at her strangely, she added: "Of course, I'll wear my shorts under the fake-fur."

If you'd like to see "her" for yourself, just go to the web site site and look under GEFS ensemble forecast (e.g 500 mb temperatures).  Of course, by the time you look Purim may be over, and she may be gone by the way of all small chances.  On the other hand, Purim miracles do happen, whether forecast or not.

Barry Lynn

Sunday, February 24, 2013

Weather It Is (A Glancing Blow, and Then a Shift)

Good Morning:

A weak storm persists to cloudy the skies a bit, with light rain scattered here or there.  However, it's not enough clouds or rain to dampen the Purim Spirits.

The storm will pass today and then a rather nice and prolonged warm up will ensue.  The weather pattern seems to be shifting towards spring.  There a storm expected to approach us on Friday, but for the moment it fails to phase with the northern Jet-Stream energy that represents some of winters coldest air of the season.  Instead, the coldest air passes off to our east and our approaching storm just weakens such that we may not even notice its passage.

This is as good thing for those planning weddings and marathons at the end of the week!

Barry Lynn

Thursday, February 21, 2013

Weather It Is (Don't Drink Too Much!)

Good Evening:

The ups and downs of the weather just may make you feel a bit Purim drunk.

Our beautiful weather will come to an end on Shabbat, as a storm system moves in from the west.  It's a cool, but not cold winter system that will bring  a general light rain to center and northern parts of the country. 

The skies should clear Sunday morning, and then temperatures will be on the upswing, and peak about mid-week.  In fact, the weather pattern looks a bit like a rollercoaster.

Hence, one might be forgiven for feeling a bit tipsy after Purim when temperatures then begin a dive towards (possibly) much colder levels towards the end of next week again, as another storm approaches.  This storm may carve out a deep trough extending into northern Europe, and may be able to tap much colder air than usual.  Will it be enough to whiten the ground?  Stay tuned.

Shabbat Shalom,
 

Monday, February 18, 2013

Weather It Is (The Ups and Downs)

Good Evening:

My impression is that the weather was a bit chilly this morning.  It wasn't cold, but it was still chilly. Yet, we're under the influence of high pressure, and temperatures should moderate nicely upwards by the end of the week.

By the end of the week a storm will approach us and we'll have another bout of light to moderate rain, and temperatures will head down again, only to head up again on the tail end of the storm.

Looking at the GFS ensemble forecast, we don't see anything really interesting on the horizon.  But, looking at the GFS "deterministic" forecast shows high pressure moving into Central Europe and extremely cold air associated with a trough of low pressure pressing southward (very late February).  At the same time, a storm begins to move under (south of) the high, and one gets a hint that this system will merge with the northern trough.  These are the ingredients of a late winter (winter) storm that might impact our area very late February or early March.  If not, it might just be on to spring!

Barry Lynn

Friday, February 15, 2013

Weather It Is (Going Backwards)

Good Afternoon:

The weather feels quite winter like, although the temperature is about 10 C.  The reason it feels chilly is that there is a strong wind.  In fact, there is going to be a series of weak storms which will make the air feel damp as well.

Yet, the long range forecast suggests that the weather pattern has indeed made a choice, a choice to retrograde westward.  As the winter trough pulls back, this has the potential to eventually bring much warmer air into our area, especially towards the end of next week.

Let's see: it is the 15th of February.  Looking 10 days out doesn't indicate any real winter on the horizon. On the other hand, last year's snow came on a Friday on March 1st.

Shabbat Shalom,

Barry Lynn

Tuesday, February 12, 2013

Weather It Is (A Choice)

Good Evening:

In the next few days the temperatures are going to rise by more than 10 degrees Celsius, ahead of our next wintertime system.

Our next bout of winter should bring a decent rain on Shabbat or very early next week.  Afterwards, the weather will have to make a choice, up or down.  If the temperatures continue to cool, then the next storm system will be followed by an even colder system that could bring the white stuff back into the neighborhoods of the central mountains and northern mountains. 

There is about a 50% chance that the second storm system will affect us.  Hopefully, the situation will become more obvious as we move along a few days in the week.

Barry Lynn
Here is the GEFS precipitation forecast from our web site. You can see how some of the ensemble members continue to produce more rain as time goes on.  This corresponds to the continued drop off in 500 mb temperatures, immediately below the precipitation graph.