Severe weather could be in store for parts of the Central Plains tomorrow (April 14), thanks to a weather pattern taking shape over the middle of the country.
A trough of low pressure between two high pressure systems is driving two different air masses together right over the plains: Dry air from over the Mojave Dessert is being forced against moist air from the Gulf of Mexico. Where these two different types of air meet, the ideal conditions for convection, and thus severe thunderstorms, is created.
The image above highlights the areas (in pink) that are expected to see the most potential for convection based on data from the National Oceanic and Atmospheric Administration's North America Model averaged from April 12-16. Convection happens when the air in the atmosphere is unstable, forcing warm, moist air upward, which then causes it to cool and the moisture in it to condence, creating clouds and rainstorms.
Overlaid over the model output are the wind directions expected during the same period. The streamlines coming out of the central high pressure off of North Carolina can be seen sweeping into the Gulf of Mexico, picking up the highly energetic, moist air, and moving northward into the Plains. As the air moves north, is met on the west side of the front by the dry air from the Rockies. This area of confluence is under watch by the Storm Prediction Center and NOAA Satellite Analysis Branch as areas where severe storms, hail, and tornadoes may possibly form over the next few days, with the highest potential occurring on April 14th.
This time of year is the unofficial tornado season in the central United States, as spring is a transitional period, when masses of warm and cool air are more likely to collide and create the thunderstorms that spawn tornadoes. April of last year saw a devstating outbreak of tornadoes that hit across Dixie Alley, setting a record for number of tornadoes in one month .
The 2012 tornado season had an early start , with some tornadoes making a rare Leap Day appearance . Already, tornadoes early in March have become the first billion-dollar disaster for the year . Tornadoes also recently caused damage around Dallas, Texas .