Weather Is Cool, Kids

A PhD student in atmospheric science - specialized in tornadic storms

[llvorticity]

Outflow Dominant

The outflow from this storm was very cold and cut off the rotating updraft. If you look on the left side of the picture, you can see a slanted wedge of dust out ahead of the cloud. Right above it, you see new cloud forming.

When a storm becomes outflow dominant, warm air rides up and over the cold pool (the wedge of dust we see here) and becomes the new updraft of the storm! Depending on how cold the outflow is, the storm speeds up. At this point, tornadoes are no longer the main threat -strong straight-line winds are!

June 9, 2017

Rugby, ND

[llvorticity]

A “Mothership” Supercell

The term “mothership” isn’t an official classification, but it is commonly used by storm chasers when the main rotating updraft of a supercell is visible and resembles, well, a space ship.

Imperial, NE - 2019

[atmospheric-phenomena]

Supercell,  Burwell Mammatus clouds by Ryan McGinnis

[llvorticity]

^^^ Photo Credit - Alex Erwin

Not all tornadoes spin the same direction!

Most tornadoes (especially those that extend directly under the mesocyclone) spin cyclonically (counter-clockwise in the Northern Hemisphere). This tornado - which surprised our crew a bit when it appeared so close - spun the opposite direction, or anticyclonically. It was on the southern edge of a rear-flank downdraft surge within the tornadic supercell (it can be seen under the left edge of the cloud base in the first photo). For context, a cyclonic tornado would be expected under the lower portion of the cloud (known as the wall cloud) toward the right side of the first photo.

Near Goodland, KS - June 8, 2019

[llvorticity]

This cloud looks ominous, but was really just the updraft base of a regular thunderstorm in a pretty unique environment. The direction of the low level shear on this day led to the formation of a rare anticyclonic supercell in the Texas Panhandle

Hereford, TX - June 15, 2019

[theweatherlab]

A fine solstice to you all. 

[lloerwyn-deactivated20201104]

Here’s one of my favourite weather phenomena, the Asperitas cloud. Added just last month, It’s the first new addition to the International Cloud Atlas since the cirrus intortus was included in 1951. It was first proposed in 2009 by Gavin Pretor-Pinney, the founder of the Cloud Appreciation Society.

Common in the American plains, Scotland, and Australia, Asperitas clouds may look stormy, but they rarely herald tempestuous weather.

Gavin Pretor-Pinney says that classifying clouds makes us care more about what’s above us, and observing them gives our minds a chance to focus on something other than our busy modern life.

[llvorticity]

There is currently a collaborative field program going on called TORUS - Targeted Observations by Radars and UAS of Supercells. Texas Tech University, Oklahoma University, Colorado University, University of Nebraska, NOAA and the National Severe Storms Labroratory are all working to gather mobile radar observations and in situ data collection of supercell storms (storms with rotating updrafts-the most prolific producers of tornadoes).

The NOAA Hurricane Hunter, RAVEN unmanned aircraft, OU and NSSL mobile mesonets, and TTU mobile radars are pictured here.

[llvorticity]

A wall of dust approaches Lubbock, TX - dust storms can be caused by a variety of weather phenomena like frontal passages or high winds produced by a line of storms. This one was caused by thunderstorms moving off the mountains of New Mexico and the dust travelled all the way across the Texas panhandle