Rain acomin’ to the northeast

Here comes the rain again
Falling on my head like a memory

We need a good rain here in the northeast United States – and we’ll get one.

As of 6am, Tuesday, low clouds have already covered the DC metro area.  Rain will arrive there during or just after the morning rush.  It will sweep in to Philadelphia during the evening rush and into NYC after dark.

The steady rain will progress up the northeast corridor, in DC by this afternoon, Philadelphia by dark, NYC by midnight and Boston by Wednesday morning.

Snapshot of the morning weather observations from the National Weather Service’s aviation data interactive map.    At the web site, placing your cursor over the airport will give you the latest weather conditions and the aviation forecast.  The forecast is in code, but most of it is not hard to figure out once you realize the time at the beginning of the forecast line is in GMT, four hours ahead of EDT. symmap2.php

 

 

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View from 34,000 feet and 700 kilometers

View of ‘rolling’ clouds made as the air is bounced up and down after passing over mountains.  Photo from 34 thousand feet with my iPhone, on my flight from DCA to New Orleans last Tuesday.  That afternoon, the Aqua satellite made its afternoon pass over the eastern United States.  The jet stream is zooming across the ‘waves’ at high speed.
See NASA Earth facebook page and NASA Earth Observatory for their view from NASA’s Aqua polar-orbiting satellite (a little higher up).  I’ve downloaded and posted their photo panorama, below my photo – go to their site to see the humongous version of the photo. (And, take minute to go to their facebook page and ‘like’ NASA’s  great post and learn just a bit more about these ‘mountains in the sky’. )31143662_1160517410757091_5656505524066189312_n

Here’s NASA’s photo from low earth orbit – a montage of photos from the Aqua polar orbiting satellite – see the waves in the cloud cover over Virginia (the lower, or southern-most part of the cloud cover over land):

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Temperature roller coaster for the east

Hang on tight! Here we go up to the top of the weather roller coaster as temperatures reached 80 degrees on Friday and will bump up to the 70s on Saturday.  Then, hold on to your flip-flops as the temperature sinks 20 degrees by sunset Saturday and another 15 degrees by Sunday morning.

The coaster settles in for a smooth, level, but cold run with all day Sunday at 40 degrees.  Yes, all day.

Monday, we get to the 50s again, but with an inch or two of rain (which we need).

Big storm moving across the country, with a big, cold high pressure system hanging out to our north.

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Computer model forecast for overnight Monday. Black lines are surface pressure. Dashed lines are average temperature over the lower atmosphere. Red is warmer, blue is colder.

If you want more raw weather output, here’s the Global medium range model forecast for the next ten days. . . .

Screenshot-2018-4-13 SpotWx

 

Pop out up in the morning while it’s still dark out!

Step outside before sunrise – the morning sky has bright planets, easily seen.

Come on! Throw on those shoes and jacket you use to pop out and collect the mail and slip outside if the sun isn’t up yet!  Mars and Saturn are bright and still an astounding pair, low in the south.  Jupiter is low in the southwest – just about to set, the brightest of them all.MobileObsScreenshot_180410_142740

On Wednesday, the forecast is for a clear patch of sky in the morning.  Then, the moon will be a “C” for “crescent”, in the southeast.

Want a preview?  Jupiter rises around 10pm in the southeast, as today’s clouds start to clear off.  You’ll still have Orion and the winter sights just above the western horizon.MobileObsScreenshot_180410_144136

Just take a peek!

Two space stations at once Wednesday night

The International Space Station and the Chinese space lab Tiangong-2 will be in our sky at the same time, tonight, Wednesday, April 4th, according to heavens-above.com.  You’ll need a clear horizon to your northwest and north as the ISS will pass just under the W-shaped Cassiopeia from 9:01 to 9:04pm, then go into the earth’s shadow.  Weather may be clear, but will be windy.

Both will be visible to the unaided eye – no optical aid needed!  Tiangong-2 will be bright, but not as bright as the ISS.  T-2 will pass over us almost overhead.

Below are maps from heavens-above.com for the two outposts in space.

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Overflight of Tiangong-2. Time marked in 24-hour clock and EDT.

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ISS overflight from Westchester County, New York. Time is marked using the 24-hour clock in EDT.

If you are not in the NYC metro area, use heavens-above.com to find out if you can see this from your area. More likely to be seen from NYC north and eastward.

Tiangong-2 is not crewed now.  It is still being controlled by the Chinese space agency, but it will not be crewed again, as China prepares a new space outpost.  Expedition 55 is at the ISS, with six souls aboard.

Heads UP! for April 2018

Heads UP! for April 2018

Jupiter is a wonderful sight in a telescope at 44 arc seconds wide from mid-April through early June.  In June, Jupiter will be highest in the prime time evening skies, while, now, it’s highest at midnight.   But why wait for summer, with the late sunrises due to daylight time, it’s a great sight in the morning twilight.

Saturn and Mars pair up in that same morning sky.  They are patiently waiting offstage for Jupiter to have its time in the spotlight. They start out April right next to each other, seemingly hovering over the teapot of Sagittarius.  They make a wonderful contrast as they pair up in the morning sky around early in the month – one is reddish; one is yellowish.  They drift apart as the month goes on.  A plump Moon joins the planetary couple on the morning of the 7th for a nice photo op.

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Panorama of morning sky with Saturn, Mars and Jupiter from late March. Canon XS on tripod 1/2 second exposures at f/2 and ISO400, 50mm lens.

Mars and Saturn start April at the same brightness, but Mars jumps a full magnitude brighter by the end of the month.  In a telescope (of any kind) Mars still appears smaller than Saturn’s disk, even as Mars gets large enough by the end of the month for moderate-sized telescopes to see some details.  Does Mars leave Saturn for a dwarf planet?  Mars happens to pass Pluto’s neighborhood in the sky near the end of April.  It’ll be nice to use Mars to point out Pluto’s location.

Mercury is in conjunction with the Sun on the 1st.  Then it makes a weak swing into the morning sky; not very easy to see from the Northern Hemisphere. It’ll be easier to see online in the Solar and Heliospheric Observatory’s C3 camera view through the 6th (if they fix the problems with the website).  Uranus’s conjunction with the Sun will be harder to see as it crosses the C3’s field from the 10th through the 27th.

Mercury yields the title of ‘closest planet to Earth’ to Mars at the end of April.  Mars keeps the title until Venus becomes the closest in mid-September through the rest of 2018.

Venus continues to arch higher from the western horizon just after dark, setting hours after the Sun.  At the far side of its orbit from Earth, in a telescope it looks as tiny as Mars and looks just slightly out of round at 90 percent lit.  Even then, it’s still the brightest planet at magnitude minus 3.9.

At the end of the month, Aldebaran sinks down, passing upgoing Venus.  Orion, to Venus’ left, looks to make a hasty departure from the evening skies.  Perhaps he left his eveningwear behind and feels underdressed.  Or, is his arm, upstretched from Betelgeuse, waving in distress as he sinks below the horizon?

Vesta is the brightest minor planet.  It passes through magnitude plus 6 on its way to magnitude +5.3 at opposition in June. It’s hanging out about 10 degrees to the upper right of Saturn in our skies.  We’ll need binoculars to see it well.

The Lyrid meteors peak during the afternoon on the 22nd. We have the chance to see up to a dozen Lyrids an hour near their peak, with the best numbers before dawn.  Elevated numbers of Lyrids are visible on the mornings of the 21st and 23rd as well.

Overflights of the very bright International Space Station are visible most evenings through the 12th.

Tiangong 1 fell out of the sky on at 8:16pm ET on April 1st into the southern Pacific Ocean.  The uncontrolled fall of China’s first space station was a great example of how slamming into even the few molecules of air per cubic meter of the Earth’s thermosphere at 18,000 miles per hour saps the orbital energy of satellites.

Tiangong 1 to Reenter Earth’s Atmosphere This Weekend

Do you want to see Tiangong 1 reenter the Earth’s atmosphere this weekend?  It may be quite a sight, but the doomed craft will be over the NYC metro area only at certain times.

People who work on estimated times of reentry of the Tiangong 1 space station have narrowed down the range to between 2:30pm Saturday March 31st and 1030pm Sunday April 1st.  Good locations with predictions: click here and here.

The craft passes over the NYC area in the morning hours.  The chances of us seeing the craft reenter our atmosphere are small, as there are only certain times when the craft is passing within sight of our area.  Check for those times so you don’t have to waste time watching when there would be nothing to see.

Here’s the list as of 12noon Friday, March 29th, from Heavens-above.com (change the location if you are not in the NYC, USA area) of when Tiangong 1 will pass over the NYC metro area, so even if it doesn’t reenter when it passes over us, you can get a last look before it goes out in a blaze of glory.  Check for updates; as the craft drops into a lower orbit, it will speed up and may arrive earlier than predicted from the present orbital information.

Passes over NYC outside the predicted range of reentry times:

Friday March 30            6:13am to 6:16am Visible in twilight

Saturday March 31       5:41am to 5:45am Visible in twilight

Passes over NYC within the range of reentry times:

Sunday April 1     507am to 511am          Visible in twilight

6:39am to 6:43am       Daytime

8:11am to 8:15am       Daytime

9:44am to 9:47am       Daytime

Outside the presently predicted reentry time range

Monday, April 2   4:32am to 4:35am Visible in twilight

6:03am to 6:07am  Visible in twilight

Note the 5:07am to 5:11am pass Sunday morning, Tiangong 1 will be visible in twilight near the center of the predictions for reentry at 6:30am EDT.

Daytime passes won’t be visible unless the craft is reentering at that time and also, only if reentry is very bright.  The 6:39am pass Sunday morning is right near the center of the predictions. If you want to stake out the station at that time, get out a bit early and look to the left of the setting moon, then to the north of zenith and then down toward the rising sun.

Hey, a few minutes invested in watching might give you a memorable experience only a few will see.

Thanks to astrobob for his great article on this event!