WW2010
University of Illinois

WW2010
 
welcome
 
online guides
 
archives
 
educational cd-rom
 
current weather
 
about ww2010
 
index

Online Guides
 
introduction
 
meteorology
 
remote sensing
 
reading maps
 
projects, activities

Meteorology
 
introduction
 
air masses, fronts
 
clouds, precipitation
 
el nino
 
forces, winds
 
hurricanes
 
hydrologic cycle
 
light, optics
 
midlatitude cyclones
 
severe storms
 
weather forecasting

Air Masses, Fronts
 
introduction
 
air masses
 
fronts
 
advection

Fronts
 
introduction
 
stationary front
 
cold front
 
warm front
 
occluded front
 
dry line

Warm Front
 
definition
 
wind shift
 
higher dew points
 
cyclones
 
precipitation

User Interface
 
graphics
text

.
Finding Warm Fronts Using Wind Direction
shift from east-southeast to south-southwest

Warm fronts are not always identifiable by simply examining the temperature field alone. Other fields must also be taken into consideration. For example, below is a surface weather map with an analyzed low pressure center (red "L") and associated cold front (blue line) and warm front (red line). The numbers are surface temperature reports and the symbols are wind barbs, indicating wind direction and wind speed.

At the time this map was generated, temperatures ahead of the warm front were in the 40's, while behind the front, temperatures were only slightly warmer (in the 50's). However, notice the change in wind direction (as indicated by the wind barbs) from one side of the warm front to the other. Winds ahead of the warm front were generally from the east, while behind the front, winds had shifted around and were blowing out of the south. This sudden shift in wind direction was the key indicator that a warm front was present.

A sudden change in wind direction is commonly observed with the passage of a warm front. Before the front arrives, winds ahead of the front (in the cooler air mass) are typically from the east, but once the front passes through, winds usually shift around to the south-southwest (in the warmer air mass).



definition
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.

higher dew points