Theta and Theta e for Estimating Areas of Maximum Thermal Lift

Equivalent Potential Temperature (Theta e) and its abbreviated counterpart, potential temperature (theta), are important parameters that determines relative buoyancy of airmasses. Identifying where maximum surface theta e is often correlates with areas of strongest convective lift. If there is good capping aloft but good lapse rates and dewpoints are not too high these parameters that helps identify where zones of good thermal lift can be found. Here is a good description of Theta e and theta from meteorologist Jeff Habby

and more on Potential temperature:

Theta is temperature simply adjusting for pressure altitude, discounting the adjustment for water vapor. From a practical standpoint, theta can be used in place of theta e for estimating thermal heights for general soaring conditions atmospheres that are capped and not inclined to overdevelopment. Until LcL or CcL is reached and the latent heat is released, the influence of atmospheric moisture on density/buoyancy is small. Estimates of surface theta can be easily made from surface reporting stations where the elevation is known.  Here are two useful sites for obtaining these data:
http://forecast.weather.gov/MapClick.php?lat=36.88181755936464&lon=-121.40853881835937&site=mtr&unit=0&lg=en&FcstType=text

http://www.wrh.noaa.gov/mesowest/frame.php?map=mtr&limit=1
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With the paradigm shift occurring with interactive forecast tools on the Internet, it is possible to get broad based estimates of where maximum surface theta is both forecast and reported along with forecast or current surface dewpoints.  These data can then be used in conjunction with forecast soundings from NOAA FSL to determine thermal heights and cloudbase.  Here is a link to the site with a sample location near Hollistere, CA: http://rucsoundings.noaa.gov/plot_soundings.cgi?data_source=Op40;latest=latest;n_hrs=8;airport=36.881818,-121.401672;plot=Java-based%20plots&start=latest

The interactive soundings allow for determination of boundary layer (BL) tops quickly with simple inputs of the temperature and dewpoint.  The value of using estimates of potential temperature is that by adjusting for elevation/altitude, the  BL tops can rapidly by assessed simply by observing where the sounding at a particular location intersects the isentrope lines (lines of equal theta) on the SkewT.  In addition, once the theta is estimated, one does not need to click on the specific height and .

.temperature to obtain the BL mixing profile, but anywhere on the estimated potential temperature line.

Finding a sounding location:
Kurt Thames created an interactive Googl;e Map that links ot the FSL Forecast sounding for a selected location by clicking the the location.  This map allows close correllation with the NWS interactive Google Maps for both forecast and current temperature. http://thams.com/flying/skewTmap.html

Sources of Theta on FSL Soundings and how to use: < to be created>

Blog Setup

The scope and purpose of this blog is to document meteorological issues in various pursuits I undertake. Much of what I do in various aspects of my life are influenced directly or indirectly by dynamics of the earth's atmosphere, not the least of which is breathing. In vocational, avocational and in recreational pursuits, meteorological dynamics determines the limits and is sometimes the driving force that determines the success and enjoyment of my endeavors. Beyond that, there are metaphores for life that become apparent in met phenomena that gives me in depth understanding of more than just the subject at hand. We are creatures of the air, although most of us spend most of it in the lower 2 meters and appear to be attached to the ground. What happens in the "upper air", however, is crucial to life itself. So, the title of the blog "Living in the Earths' Atmosphere: Recreational Meteorology".
My passion for meteorology is spurred largely because I love to soar. It is fundamental to the sport, but also, soaring aircraft are in turn powerful tools for understanding the dynamics of the atmosphere. So, much of this blog is geared toward soaring experiences that utilize special meteorological conditions, but not limited to that. The blog will go where my mind map takes me, since, like metaphores, there is often overlap with other arenas.