Editing Warm front (section)

==Characteristics==
If the air mass is relatively stable, [[rainfall]] will increase until the front reaches the location, at which time the clouds can extend all the way to the earth’s surface as [[fog]].  Once the front passes, the location experiences some warming and clearing.  If the [[air mass]] is unstable, [[thunderstorm]]s may precede and follow the front and temperature changes will be larger.<ref>{{cite book|url=https://books.google.com/books?id=Ew3MBjbw4OAC&q=anafront+book&pg=PA309|title=The environment: principles and applications|author=Chris C. Park|page=309|publisher=Psychology Press|year=2001|access-date=2010-12-17|isbn=978-0-415-21771-2}}</ref>

In the [[northern hemisphere]], a warm front causes a shift of [[wind]] blowing from southeast to southwest, and in the [[southern hemisphere]] a shift from winds blowing from northeast to northwest. Common characteristics associated with warm fronts include:
{| class="wikitable"
|-
! Weather phenomenon
! Prior to the passing of the front
! While the front is passing
! After the passing of the front
|-
| Temperature
| Cool
| Warming suddenly
| Warmer, then leveling off
|-
| Atmospheric pressure
| Decreasing steadily
| Leveling off
| Slight rise followed by a decrease
|-
| Winds
| 
* South to southeast (backing) (northern hemisphere)
* North to northeast (veering) (southern hemisphere)
| Variable
| 
* South to southwest (veering) (northern hemisphere)
* North to northwest (backing) (southern hemisphere)
|-
| Precipitation
| Usually none, but in summer or warm temperatures, cumulus congestus may continue to exist under cirrostratus and altostratus creating light to moderate showers.
| Persistent rain, usually moderate with some lighter periods and some heavier bursts. In winter, snow may turn to rain after passing through [[ice pellets]] and [[freezing rain]].<ref>{{Cite book|title=Meteorology today : an introduction to weather, climate, and the environment|last=Donald|first=Ahrens, C.|date=2007|publisher=Thomson/Brooks/Cole|isbn=978-0495011620|edition= 8th|location=Belmont, Calif.|pages=298–300|oclc=66911677}}</ref>
| Light drizzle, gradually ceasing.
|-
| Clouds
| [[Cirrus cloud|Cirrus]], [[cirrostratus]], [[altostratus]], [[nimbostratus]],  then [[stratus cloud|stratus]].  Other clouds can also often be seen, including [[cirrocumulus]] amongst the approaching cirrus, [[altocumulus]] with or instead of altostratus (particularly if the front is weak), and occasionally [[cumulonimbus]] along with or instead of nimbostratus in summer.  Additionally, [[stratocumulus]] often appears underneath the main altostratus deck and stratus [[fractus]] typically forms in precipitation falling from the thick nimbostratus layer. Often in warm temperatures, rain bearing [[cumulus congestus]] clouds can appear under the cirrostratus, and more rarely [[altocumulus castellanus]] clouds if convection is sufficient.  In cold humid conditions, low airmass stratus or [[fog]] may obscure the main frontal clouds.
| [[Nimbostratus]], sometimes [[cumulonimbus]]
| Clearing with scattered [[stratus cloud|stratus]] and [[stratocumulus]]. If the warm front is part of a depression, there is often a sheet of altostratus (often broken in places to altocumulus) above this which thickens when the cold front approaches.
|-
| Visibility
| Poor
| Poor, but improving
| Sunny
|-
| [[Dew point]]
| Steady rise
| Steady
| Rise, then steady
|}