A dry line, (also called dew point line, or Marfa front) is an important factor in severe weather frequency in the Great Plains of North America. Marfa is a city located in the high desert of far West Texas in the Southwestern United States. Severe weather is any destructive weather phenomenon. The term is usually used to refer to severe thunderstorms and related phenomena such as Tornados The Great Plains are the broad expanse of Prairie and Steppe which lie east of the Rocky Mountains in the United States and Canada It typically lies north-south across the High Plains states (and sometimes stretching into the Canadian Prairies) during the spring and early summer, where it separates moist air from the Gulf of Mexico (to the east) and dry desert air from the south-western states (to the west). This article is about a geographic region in the United States The Canadian Prairies is a region in western Canada, which may correspond to several different definitions natural or political The Gulf of Mexico ( Spanish: Golfo de México) is the ninth largest Body of water in the world
The dry line is also sometimes important for severe convective storms in other smaller regions of the world, particularly Bangladesh and adjacent eastern India, and south-eastern South America. ( Bengali: বাংলাদেশ inc-Latn Bangladesh) officially India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a
Near the surface, warm moist air is more dense than dry air of greater temperature, and thus the warm moist air wedges under the drier air like a cold front.  At higher altitudes, the warm moist air is less dense than the cooler, drier air and the boundary slope reverses. In the vicinity of the reversal aloft, severe weather is possible, especially when a triple point is formed with a cold front.
The dry line typically advances eastward during the afternoon and retreats westward at night, mainly due to the increased mixing down to the surface of drier air aloft, rather than the air mass' surface density contrast. However, a strong storm system can sweep the dry line eastward into the Mississippi Valley, or even further east, regardless of the time of day. The Mississippi River is the second longest River in the United States, with a length of from its source in Lake Itasca in Minnesota to A typical dry line passage results in a sharp drop in dew point, clearing skies, and a wind shift from south or south-easterly to west or south-westerly. The dew point (sometimes spelled dewpoint) is the Temperature to which a given parcel of Air must be cooled at constant Barometric pressure, Wind is the flow of Air or other Gases that compose an Atmosphere (including but not limited to the Earth's) (Blowing dust and rising temperatures also may follow, especially if the dry line passes during the daytime; see dry punch). Dust is a general name for minute Solid particles with Diameters less than 500 micrometers. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature A dry punch is meteorological slang for a surge of drier Air, normally a Synoptic scale or Mesoscale process These changes occur in reverse order when the dry line retreats westward. Severe and sometimes tornadic thunderstorms often develop along the slope reversal zone east of the surface dry line, especially when it begins moving eastward. A tornado is a violent rotating column of air which is in contact with both the surface of the earth and a Cumulonimbus cloud or in rare cases the base of a Cumulus