How do i interpret a 500mb map?

Question

Below are different links to the same map.. 500mb map that i have no idea how to read.. can you please give me examples

<a href="http://s74.photobucket.com/albums/... target="_blank"><img src="http://i74.photobucket.com/albums/i... border="0" alt="Photobucket"></a>

[IMG]http://i74.photobucket.com/albums...

http://s74.photobucket.com/albums/i267/ratgirl102486/?action=view&current=mondaymarch10500mb.gif

Answer 1

Wind are recorded in knots.  A triangle indicates 50kts of wind and each additional bar is 10 kts.  So, if you have two triangles and a bar, that is 110kts of winds. The wind direction is 0-360 degress.  Pressure is recorded in millibars and temperatures in celcius.   The Dew point is located below the temperatures.  That is the dew point depression, which is subtracted from the temperature.

Answer 2

First off, saying 500mb is at 18000ft is an ESTIMATE. The whole point of the 500mb map is to show you a cut out of how high a certain pressure (500mb) is in the atmosphere. There are wind barbs on the map, showing you direction and speed of winds at 500mb. There is a three digit number next to the wind barbs showing you how high up in the atmosphere 500mb is (the three digit number is in decameters, add a 0 and you have the height in meters). The two digit number in red (one on top) shows the temperature at the given height, and the number in green (bottom one) shows the dew point temperature at the given height. The black lines are contours/isobars (I&#039;m horrible, I know, but I&#039;m blanking on which is in the upper atmosphere and which is on the surface), which just show the overall pattern of the heights, and the red lines are temperature lines, showing the distribution of temperature.

The 500mb map just shows us weather folk a nice slice of the atmosphere, allowing us to see the placement of features. Put a day or two&#039;s worth of these together, and we can see continuity, movement, and overall flow of these features, and that helps us to predict the weather.

Hope that helped!

Answer 3

This is how you read it.

http://www.aos.wisc.edu/~hopkins/aos100/...

Just if you don&#039;t know 500 mb is at 18000 feet

Answer 4

I don&#039;t think that is a very good link, that the first answer gave you, because that is for surface maps.  The 500 mb chart essentially shows the weather half way up in the atmosphere (half the air is below and half above). Each contour line gives the height of the 500 mb pressure surface at that location.  In the northwest corner of the map, off of British Columbia, you&#039;ll see an upper level low pressure area.  The contour lines that lie to the south of it and &quot;point&quot; to the south are what&#039;s called a low pressure trough.  Usually the east half of a trough has stormy weather.  To the east of the trough there are contours that &#039;&#039;point&quot; north--that is, if you connect the northernmost point on each contour line (through northern Nevada, Montana and the border between B.C. and Alberta) they form what&#039;s called a high pressure ridge--usually the east side of the ridge has good weather.  There is another weak trough in the Ohio River Valley.

Winds will blow parallel to the contours and the wind speeds are given by the barbs.  The winds will blow stronger where the contours are closer together.  The red numbers are temperatures in Celsius and I believe the dashed line are contours of vorticity, although they aren&#039;t labelled as such.

Correction: after enlarging the image a bit more, I guess the dashed contours are temperature.