Pressure and Dew point

Reference Weather Map

Current Weather Map

This panel depicts sea-level pressure and dew point temperature. This chart is useful for finding fronts and high and low pressure systems.

The solid black contours represent pressure contours (isobars) in millibars. The isobars have a contour interval of four millibars. The wind speed is directly related to the distance between the isobars. The closer the isobars are together, the stronger the pressure gradient, and the stronger the wind.

The dashed color filled regions represent areas of equal dew point (isodrosotherms). The contour interval of the dew point contours is five degrees Fahrenheit. From the map above you can sometimes find warm fronts, cold fronts, and drylines. Fronts are usually located where the dew point changes drastically over a short distance.

dew point reports
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

Pressure Maps