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

NOTE: We've guessed that you're not using a client that supports colored tables and have tried to compensate. Low graphics mode looks much better on clients that do... we recommend switching to Netscape 3.0 or Microsoft Internet Explorer.
.
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