Greetings, and welcome to the official blog of the 7th Annual WKU Weather Analysis and Forecasting Field Methods Course (a.k.a. Storm Chase)! Daily updates on the group’s activities and targets will be posted here.
Last week, our team of students assembled for the first time and, after filing the proper documentation, began a forecast discussion to decide our departure date and target location. Modeling indicated a trough moving through the Southern Plains on Monday, and positioned the trough neutrally over the Four Corners by Monday evening. Moisture advection looked excellent throughout central Oklahoma, and forecast soundings in the area showed favorable conditions there, as well as closer to the associated warm front in north-central Kansas. Since Monday appeared chaseable, we decided to depart Sunday to prepare for a chase day on Monday
We departed Bowling Green at 9:30 AM CST Sunday morning and made our way south and west towards Oklahoma City. After a short lunch stop near the Shiloh Battlefield and a short dinner stop near Fort Smith, AR, we arrived at our hotel for the evening in Yukon, OK, just west of Oklahoma City at around 9:00 PM CST. After running through a quick data analysis and a relaxing soak in the hotel hot-tub, we went to bed with our alarms set for a 9:00 AM CST forecast discussion to select targets for Monday.
Keep updated on this site and on Twitter by following @wkustormchase!
-Isaac Bowers
Leg 1 of our journey (in blue), 5/15/16, Bowling Green, KY – Yukon, OK
So excited to follow your journey! Hope you have some luck chasing!
Happy Hunting!!
Love hearing about your daily adventures!! Lots of luck on your chase!!
What a great experience for you all! Keep the info flowing!
Sure enjoying this!! Great Grandpa & Great Grandma!!
So explain “Convection Initiation”.
I assume it is the point at which the sun heats the surface sufficiently to cause convection to begin resulting in instability and the subsequent cooling of that air at higher altitudes which initiates a thunderstorm.
Could that be correct?
In most cases, the atmosphere cools with height. However, the rate at which this cooling occurs is very important when trying to create thunderstorms. These rates are called “lapse rates”. Dry air lapses at a constant rate, and moist air lapses at a constant rate, but the two rates are very different. Because of the nature of the condensation process, heat is added to the environment during condensation events. Therefore, moist lapse rates are lower (less negative) than dry lapse rates.
If the environment loses heat more slowly than a moist parcel, the parcel cannot continue rising past that layer, since it will eventually become cooler than the environment and sink. We call this convective inhibition, or CIN. When the opposite occurs, the moist parcel is free to rise. We call areas where this occurs CAPE. In the morning hours, there generally exists a temperature inversion in the atmosphere since land surfaces cool faster than the air above them. This results in a large value of CIN and limits convection. During the day, surface heating and mixing in the boundary layer slowly erode this CIN.
When rising air is able to overcome the CIN it encounters on the way up, it can freely rise once it passes that layer. We call this event “caps breaking” or “initiation”. Usually this signifies the beginning of a severe event.