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Lala Impacting Hawaii; Severe Thunderstorm and Flash Flooding Risks; Excessive Heat

Areas of gusty winds, heavy rain leading to flash flooding, and high surf continue across portions of Hawaii as Tropical Storm Lala continues to move away from the islands. Severe thunderstorm, heavy rainfall, and flash flooding threats continue from the Midwest to the Mid-Atlantic and across the central High Plains. Record heat continues for areas of the central/southern Plain into the Southeast Read More >

Mountain Wave Activity Over the Southern Rockies

When stable air flows over the rugged terrain in and around New Mexico, mesoscale circulations known as mountain waves can develop. An example is shown in the visible satellite image below. When the wind speed is sufficiently strong and perpendicular, or nearly-perpendicular to mountain ranges, waves develop over and downstream of the barriers. If enough moisture is present in the air, clouds will develop in the portion of the wave with upward vertical motions. While the wind speeds may be 30 kts or greater, the waves remain nearly stationary for periods up to several hours. While these waves are visually appealing, both in satellite imagery and from the ground as lenticular clouds, these waves are often associated with turbulence and therefore, are considered to be an aviation hazard.

A study on criteria associated with mountain waves over New Mexico was completed in 2004, and is available in pdf format.

animation of satellite imagery depicting mountain waves
 

Visible imagery from 18 October 2004 illustrating an extensive area of mountain waves over the Four Corners region.