Heads UP! for February 2018

No talk of ‘supermoons’ this month!  February’s 28 days are shorter than the lunar ‘month’.  With the lack of a full moon in February, there may be little note of lunar perigee occurring just two days and ten hours before the next full moon on March 1st.

The bright planet trifecta in our southern skies gets going in February, with Jupiter, Mars and Saturn as the (non-stellar) stars of our show.

Jupiter reaches its highest altitude at the break of dawn, only 30 degrees above our southern horizon.  With Jupiter at quadrature, 90 degrees from the sun, it rises in the middle of the night and its moons do marvelous disappearing and reappearing acts in Jupiter’s shadow and behind the planet. Some of the best mornings are on the 4th, 6th, 13th, 24th and 17th, for Western Hemisphere locations.  See http://wwwcdn.skyandtelescope.com/wp-content/uploads/WebJphenTab2018.pdf  for a full set of times.  Any telescope will show most of these events.  Just for fun, on one of those mornings, follow Jupiter in the daytime sky and see how long you can spot it.

Mars seems lost.  At magnitude plus 1, it doesn’t stand out much in the dawn sky.  While its tiny size (6 arc seconds) makes it a featureless orb in all but the largest telescopes in the steadiest skies, it looks noticeable lopsided in any telescope.  It stays lopsided, around 90 percent sunlit, through April.  By then, Mars will appear almost twice as large as it is now, on its way to 24 arc seconds wide, during what will become known as the summer of the giant planets!

February is a good month to compare Ares (Mars) nearby its rival anti-Ares (Antares). They are both about magnitude plus 1.0.  How are they different? Antares shimmers as a point source of light and Mars’ light is steadier, averaged out as it is spread across tiny variations in our atmosphere.

Saturn completes the trifecta, low in the southeast, but worth a glance if you are already out to see Jupiter. On the morning of the 11th Saturn floats under the thin moon.

Mercury and Venus are deep in the sun’s glare.  Watch early in March as these two pop up together into bright evening twilight.

The two brightest of the are-they-or-are-they-not-really-members of the planet club are Minor Planet Ceres, near Mars in our skies, and asteroid Vesta, in the evening skies in Cancer.  The Dawn spacecraft visited both of these tiny worlds.  Ceres and Mars are almost the same distance from Earth this month, but Mars is seven times larger in diameter and Ceres and Vesta are a dim, but findable in binoculars, magnitude plus 7.

The Milky Way still arches high across our evening skies.  We are looking out the backdoor of our galaxy, so the pale stream of stars is fainter than the summerside view.  We are lucky to have the Orion arm of the galaxy draped across our sky.  This relatively nearby swath of stars and gas and dust in the extended darkness of winter nights makes this season highly anticipated by stargazers.

Eclipse fans only get a partial solar eclipse on the 15th, visible from Antarctica and southern South America. The next chance for us is a middle of the night total lunar eclipse in January 2019. This month, the last quarter Moon sits between Jupiter and Mars in our morning skies on the 8th.  A tiny crescent Moon, at lunar apogee, points to Saturn on the 11th.

The International Space Station has a series of evening performances through the 14th. Morning viewings start around the 25th.

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Friday morning ice; moderately stormy pattern underway through next week

Rain and snow from over night has frozen on surfaces.  Be careful walking out to go anywhere this morning.  Spread a little granulated deicer in front of you as you walk out of the house and be careful on parking lots, sidewalks and steps. Give yourself some additional time to clear ice off your vehicle.  Temperatures will drop into the mid-20s early today and stay there, even if the sun comes out and it will be windy.  Only a few snow showers are possible the rest of the day.

The next storm is a mix of precipitation: By Sunday morning, a small snow storm may be in progress, with 1 to 4 inches being the early betting line for interior sections of metro NYC, with the more coastal areas having more of the precipitation as rain.  The next system is for Tuesday night into Wednesday.  Here’s the National Weather Service’s forecast discussion.

. . . focus of the long term is with two systems. One for
late Saturday night through Sunday night. Another is for Tuesday
through Wednesday night next week.

For the first system, low pressure from Great Lakes moves eastward
towards the region Sunday. The associated cold front moves across
late Sunday night. Precipitation arrive late Saturday night and last
through early Monday morning.

Potential for 1-4" snow for interior parts of NE NJ, Lower Hudson
Valley, SW CT, less than an inch of snow for rest of the local
region. Mostly rain outside of interior parts of NE NJ, Lower Hudson
Valley, SW CT. Coastal locations get more maritime influence from
southerly flow. Still potential for interior to trend higher with
subsequent forecasts, so left mention of the chance of 6 inches snow
in HWO.

For the second system, low pressure approaches from the southwest
from west of the Appalachians. Surface warm front passes nearby
Tuesday night for initial chances of precipitation in the form of
snow lasting into Wednesday morning. Low pressure moves across the
region Wednesday with its cold front moving across the area
Wednesday afternoon into Wednesday night. Onshore flow will promote
changeover from snow to rain Wednesday afternoon and then any
precipitation lingering behind the front with cold air advection
will end as snow. Weather trends drier with NW flow developing west
to east late Wednesday night into Thursday.

Note regarding the aforementioned previous systems, any subsequent
model trends with low pressure development along the cold front with
overall changes with the speed of the system would prompt changes in
the amount of rain vs snow with future forecasts.

&&

Superbluesmokesmudge moon

The moon looked like it had a smudge of smoke on it’s upper left quadrant, even just before the partial eclipse began. (That’s from the fainter penumbra shadow, where the sun is only partially eclipsed from the moon’s point of view.)  Here’s photos from after the partial phase began at 6:46am.  Moonset was about 7:06.

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6:54am, 7 minutes after the partial phase began. Moon also reddened, distorted in places and slightly flattened by atmospheric refraction. 250mm lens 1/25 seconds at f7.1, ISO 200

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Expanded view of moon about the same time as the photo above.

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Setting moon (tiny orange object down in the trees) at 6:58am. Dark band above it is the earth’s shadow. Pink band is illuminated by the light from the rising sun, bent over the horizon (the sun hasn’t risen yet). The pink on the moon is mostly due to our atmosphere, but the pink band in the sky is the light that will give the moon its reddish color at total eclipse (not seen in New York). 1/8 sec, f7.1 ISO 200, zoom lens at 36mm.

Is two out of three enough for the eastern USA in the loony trifecta?

Ok, you’ve heard so much about the loony lunar trifecta of January 2018.

Just for fun, indulge me, as we briefly review:

1) A second full moon in a month has become known as a ‘blue moon’.

2) A total eclipse of the moon in the earth’s shadow has been called a ‘blood moon’.

3) A full moon (only time we can have a lunar eclipse) which occurs near when the moon is closest to earth for the month has been labeled a ‘supermoon’.

The lunar eclipse part is what I’m interested in, but for the eastern United States, the moon will set before or just after the darkest part of the earth’s shadow starts to cross the moon.  So, we miss out on the best part of the trifecta.

If you are driving to work or out before sunrise on Wednesday, and have a clear view of the western horizon, check out the setting moon.  Perhaps it will have a gray cast since the sun is partially eclipsed as seen from the moon.  At 6:47am EST, the darkest part of the earth’s shadow will start to ‘take a bite’ of that part of the moon where the earth has completely blocked the sun.  For the NYC metro area, the moon will be only 2 degrees (four moon-widths) above the natural horizon and will set shortly after about 7:04am.

So, it’s going to be hard to see!

See timeanddate.com to see how what the eclipse would look like from New York City.    Here’s how it will look from the moon . . .

 

earth from moon eclipse jan 2018

Earth and Sun as seen from the Moon at 6:45am – the eclipse is just about to be ‘partial’ from our viewing point and just about to be ‘total’ from the leading edge of the moon. We are just about to rotate away from seeing the moon. Or as we call it, moonset.

wspace

Just a few minutes later, from the center of the moon (where solar system simulator views the earth from) is in the shadow of the earth, Venus would be visible. It’s hard to see Venus from earth now, because it’s so close to the sun in the sky.

That leaves us with seeing the second-closest full moon to earth in 2018 and the second full moon in January.

Each month from here on in, the full moon will be further from the earth than either of January’s full moons (as well as the full moons of last December and November).

By the way. . . that is each month, except February.  February will bring a respite from full moons, blood or blue or super.  They won’t be a full moon in February, with full moons occurring on January 31st and March 1st.

So, we’ll have a rest from full moons, and their crazy titles, super or otherwise.

 

 

 

 

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Snow for Monday afternoon rush hour, or later?

A series of weak low pressure systems are going to form off the mid-Atlantic coast today. They should be too weak and just a bit far out to sea to give us a lot of snow.  The NWS, as of 6am, is going with some light snow, beginning as rain after 3pm and ending in the early morning hours on Tuesday.   The latest output from the overnight computer models keeps the rain/snow out of the NYC area and north until well after dark Monday night.

Capital Weather Gang   is predicting snow overnight, not this afternoon.

Keep listening to the forecasts during the day as the information develops.

PS Don’t be surprised if there are some strong snow shower squalls Tuesday afternoon, as the upper air energy that was late for today’s party arrives!

WEB_Current_Weather_Map_1280x720

The latest surface weather map (5am Monday morning). The low pressure systems are forming on the cold front draped across the southeastern coast of the USA. The weak lows over the midwest are indications of energy in the upper air approaching the east coast that will help the storms strengthen as they move up the east coast. Sometimes, the upper air energy will overrun the existing inland low pressure systems and directly enhance the coastal lows.

Rain Sunday, then blips of storms slip off the eastern Atlantic seaboard for the northeast USA

Update:Evening of Sunday, January 28:  some models are moving the wave of storms closer to the coast, near the ‘benchmark’ where most storms give the NYC metro areas significant snow.  But, mostly they are going for light snow inland, perhaps more on eastern Long Island and southeastern New England.

Here’s their thinking for the week ahead .  .  .

Three precipitation events are forecast for the long term,
chance for snow Tuesday and rain changing over to snow Thursday
night into Friday as well as another chance of mainly snow next
Sunday. Snow chances on Tuesday are associated with the upper
level trough to the west and an inverted trough at the surface.
The lack of moisture and northerly winds will limit the amount
of snow. Mentioned as snow showers in the forecast across mainly
for the western half of the region including, Western Long
Island, SW CT, Lower Hudson Valley, NE NJ and NYC.

The next chance of precipitation has higher probabilities with it
and models are showing it to be mainly in the timeframe of late
Thursday into early Friday. Temperatures are warm enough for rain at
the start but strong cold air advection behind the cold front will
allow for precipitation to end as snow. While probability of
precipitation is high, the amount of rain vs snow has lower
confidence due to model differences in the cold front orientation
and differences in the depiction of low pressure along it. The
overall pattern shows a swift steering flow without much
amplification of the low, so thinking more on the lower end of
precipitation totals, around a quarter to third of an inch or less
in total liquid. Another chance of mainly snow is forecast for next
Sunday.

http://www.weather.gov/okx/winter

http://www.weather.gov/phi/winter

http://www.weather.gov/lwx/winter

http://www.weather.gov/box/winter

Update: Evening of Saturday, January 27 – From the National Weather Service Forecast Discussion:

There will be a chance of snow Monday into
Tuesday, but amounts are highly uncertain. Higher chances Monday
will be across eastern coastal sections and Monday night as well as
Tuesday will have higher chances across the interior. Models
disagree with the precipitation north of the front associated with
the waves of low pressure. Dry weather returns midweek with another
chance of rain/snow for Thursday through Friday timeframe with the
cold front passage and possible low development along it. Dry
weather returns for start of next weekend.

 

The forecast models are forecasting that the jet stream will not be able to corral all the energy needed at the same time to get a winter storm close enough to the east coast for Monday night / Tuesday.  If the jet stream bend tightens up a bit, the northeast will get a light snowfall out of a series of small low pressure systems.  In the meantime, all rain for early Sunday.  After Tuesday, the jet stream slides some colder air over the eastern USA, followed by a likely-to-be-mostly-rain event for the end of the week as warmer air sneaks back in.

gfs_namer_062_500_vort_ht

The loops of wind flow in the middle atmosphere, shown in this computer forecast for Monday evening, just don’t come together into one consistent valley of lower pressure. So the putative storm would be weak, diffuse and late. If those contour were to line up better and make a deep “V” shape, a storm would be stronger and closer to land. For now the weather service is forecasting a set of weaker storms, further off the coast.  That means, colder, but less snow for the northeastern corridor of the USA. But the NWS is watching the data and computer models for any indications of a tighter V in the jet stream which would increase the chance of a snow storm.

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Here’s the weather map the computer model makes of the upper air flow (previous map) and other factors:  A series of somewhat weak low pressure systems, far enough off the coast that the model doesn’t even give most areas any snow. But we have a ways to go.  It’s too close to rule it out yet.

Sidewalk astronomy: 8 quarters and a quarter moon

It took eight quarters for two hours of parking in downtown Mamaroneck, New York just steps from Jupiter Joe’s Sidewalk Astronomy with Claudia and Kevin from Westchester Astronomers for two hours of offering views of the moon, the Pleiades and the Orion Nebula.  We had a guest appearance of the International Space Station.

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My dob is just behind the fire hydrant.

The terminator on the moon, where the sun is rising on the lunar day, was just so full of rugged terrain, with crater rims peeking up into the blackest darkness imaginable.  This photo I took early on doesn’t do it justice, but it gives an idea of what it was like.

first quarter moon jan 25 2018crop auto

Three moon photos pieced together into one using Photoshop Elements 15.  The lighting has been auto leveled to get some more of the detail in the terminator and keep some detail in the brighter parts of the moon.  Original exposures 1/20 second at ISO 200, Canon XS and a 2x amplifier lens attached in place of the eyepiece on the 8-inch dobsonian.

Moon_Map_NASA

NASA-labeled photo about the same moon phase as we saw last night. The numbers are locations where the Apollo landings occurred. Note the crater labeled “Plato” is actually Archimedes.