Thursday, January 23, 2014

Realtime global wind, temperature, cloud, rain, pressure map

The ultimate realtime weather map for the inhabitants of our blue, not green planet

One month ago, we learned about Cameron Beccario's excellent global wind map.

Overlay: none

He's been improving the web page at (you must click this!)
and it boasts many new functions. Note that you may always click the label "earth" in the lower left corner of that page to get settings, legend (meaning of colors: hover over a color on that scale for a second to see the corresponding numerical value!), or make the settings disappear again.

Overlay: wind. Winds nearly 100 km/h currently exist on the Southern side of the Janus vortex (Northeast from Canada). The winds become stronger and more uniform as you increase the altitude; 250 hPa seems like the prettiest Goldilocks elevation.

The settings allow you to switch between local vs universal time, see the legend (the colors), learn about the source of the data, change the moment, go to your actual geographic location, choose the height according to the pressure (applies to the wind and temperature data; the water measures are always "inclusive" while the pressure is always translated to the sea level and its height-dependence is mostly trivial, anyway), choose the overlay mode, and pick your favorite projection (there are 8 choices, many of them allow you to see the whole surface at once and the deformations are funny).

There are numerous overlay modes that are being shown in the six screenshots on this page; I took them in the Chrome full screen (F11) mode.

These overlay modes include "none", "wind", "temperature", "total precipitable water", "total cloud water", and "mean sea level pressure".

Overlay: temperature (temp). Now, you may find temperatures from –50 °C in Northern Russia (all of Antarctica is warmer than –40 °C now: the penguins enjoy the summer) to +40 °C in central Africa as well as East-central Australia. If you're an American annoyed by the –20 °C temperatures, move to Southwestern Alaska where it's above the freezing point right now! ;-) Oceans' temperatures are less variable. At the maximum altitude of 10 hPa (30 km or so), the Arctic goes up to –75 °C while the equator is around –45 °C and the currently warmest Antarctica near –28 °C.

The "earth" button also offers you an "about" page with lots of extra data, Facebook ("like" it!) and Twitter home pages, and a link to the Japanese language-based edition of that page.

Overlay: total precipitable water (TPW). Antarctica, Mongolia, Greenland, and many other places have less than 1 km/m2 while the quantity reaches 60 kg/m2 in the equatorial Pacific, 40 kg/m2 in the East from Janus, and it is high elsewhere, too. Note that a "kilogram per squared meter" is a "liter per squared meter" which is a "millimeter" when it rains down.

I remind you that you may not only (hold left button plus) drag and zoom in/out the map (mouse wheel is enough) but also left-click at a place of the map and get some local information in the numerical form.

Overlay: total cloud water (TCW). Some places (East from Janus) show above 2 kg/m2 but many more other places show 0.000 kg/m2 (clear sky, sunny); this quantity is clearly much smaller than TPW above because only a tiny portion of water in the atmosphere is contained in the clouds (small droplets), most of it is vapor (waiting to be condensed and become precipitation when the pressure or temperatures change and exceed a threshold of relative 100% or so humidity). Clouds look extremely visible but they're often equivalent just to micrometers-thick layer of water! A typical cloud droplet has diameter of 10-20 microns.

All the screenshots in this blog post may be clicked at and magnified. In all of them, you see the vortex of the Janus winter storm that is still affecting the weather in the U.S.

Overlay: mean sea level pressure (MSLP). The minimum inside the Janus depression is about 966 hPa right now (it is a depression similar to tropical cyclones; the lower pressure at the center "attracts" the circulating air that is otherwise "repelled" from the center by the centrifugal force, if you allow me to use a rotating frame and fictitious forces); the center of the continental U.S. approaches up to 1050 hPa – almost 10% higher pressure than inside Janus.



  1. The Northern Hemisphere whines hurricanes, typhoons, and Climate Change! The Southern hemisphere perpetually rocks without any warm water to "fuel" the storms. Oopsie.,-100.02,481

  2. This is a really, really oversimplified description of the difference between the hemispheres, Uncle Al. ;-)

  3. Lubos, how do you get and change the Overlays?

  4. Ignore my question, I found it thanks, you are right it is lovely to watch.

  5. Awesome! There are having more fun on M82 than in here :-(

  6. John F. HultquistJan 23, 2014, 10:50:00 PM

    If you look at the area east of Washington & Oregon's Cascade Mountains with temperature and winds showing – there is a cool spot from which winds appear to diverge. This is true at some altitude but not at the surface where
    companies have placed wind towers. At my location of 2,240 feet (~680 m.) there is no wind. Zero. One of the results is all the rime clinging to everything – very pretty. Another is shown by the green line of this chart (or the lack of a green line):

    Look closely along the bottom.

  7. "Moreover, we are pretty sure that there is no potential supernova this close, so don't worry."


  8. What one should be afraid of is GRB event originated here from Earth. If you want to open your eyes then read my latest essay (participating in FQXi 2014 Essay contest) Referenced Antimatter paper is going to updated most likely today. Updated version is already available from my site.

  9. Very nice! But it is hard for me to imagine that some parts of the Sahara are colder than where I live . . . Or is it night there now?

    It's also hard for me to believe that it is around 30 centigrade here, it seems quite cold (compared to usual)... But there is a chance...
    The plot of TPW is very realistic, which a huge block of dryness in the Gobi, Thar, Sahara, etc.

  10. I am certainly waiting for a map for humidity.

  11. Thanks Lubos. I saw your first post and referenced it the other day during the most recent storm (i.e. "Janus").

    Awesome tool and I think every TV weather person should use it. I like the interaction of the Azores High and the Icelandic Low. It reminds me of a particular Hotwheels set when I was a kid;

    My favorite view is the 850mb level. Shows the wind flow over the continent. I don't care for the water vapor, etc. view. I'd like an animation feature.

    As far as the naming of winter storms I'm generally against it. Where I live in 2003 they had a borderline Cat2 hurricane named "Juan" followed by a 3 foot blizzard the ensuing winter. Inevitably and still to this day the locals call the blizzard "White Juan". I didn't live here at the time, but I don't disagree with this naming. The neighbors tell me that both storms knocked out the power for about four days.

  12. Although not discovered by an undergraduate, SN 1987A was discovered by a "technician" whom the University of Toronto had declined as a graduate student. Subsequently, of course, the welcomed him with open arms.

  13. If you want to see SN 2014J in a small telescope, here's how to find it: