**Thread under construction. I will work on this thread gradually as I get time. Please don't post anything until I'm done. I'll state when this is when the time comes.**
I will go over a number of things associated with severe weather and tornadoes, from forecasting to nowcasting. I'll start with the basics and move into more and more advanced topics.
Table of contents:
Post #1: Sounding/Skew-T
Post #2: Instability
Post #3: Wind shear
Post #4: Forcing mechanisms
Post #5: Storm modes
Part 1: Soundings/"Skew-T"
What is a sounding?
A sounding is created by the National Weather Service (NWS) by launching weather balloons. NWS offices across the US launch weather balloons at least twice a day, sometimes more if there's highly impactful weather threatening. These balloons record all kinds of data from the atmosphere as they ascend until they pop. Most importantly, they record temperature, dew point, the temperature of an air parcel (if available), wind speed, and wind direction. This data is commonly plotted on Skew-t's, also known as soundings, as seen below. Let's focus on the temperature profile first, which is the top left square of the sounding... just below where it says "bmx". I'll go over the most important parts of the sounding while leaving out more technical parts, such as the dry adiabatic lapse rate and mixing ratio lines
- You can see pressure in millibars on the left side of the sounding ("y-axis") and the height above the surface just to the right of pressure. The surface is at the bottom, the upper limits of the atmosphere is at the top.
- On the bottom of the temperature profile ("x-axis) is temperature in Celcius, labeled from -30 to 50. To trace a line of constant temperature, you don't go straight up; the isotherms are skewed to the right, hence skew-t. The isotherms are the dashed beige line. It's kinda hard to see on these.
- The solid red line within the graph is the temperature as you go up in the atmosphere.
- The solid green line within the graph is the dew point as you go up in the atmosphere.
- The dashed dark red line within the graph is the temperature of the air parcel as it goes up in the atmosphere.
- On the opposite side of pressure is the wind which is shown with wind barbs and the units are in knots (1 knot is approximately 1.1 MPH). The side of the wind barb with either a flag, a line, or half a line, is the direction the wind is coming from.
- Building off of wind barbs is the hodograph, which is just a way to visualize how winds change with height.
For the purpose of severe weather, these are really the main things that you need to be able to identify. Now I'll get into the fun stuff.