Helene's Lasting Impacts
And more tropical trouble in the gulf brewing?
It is very sobering for someone who chases down significant weather events to see such a hugely impactful storm on both lives and property. Watching the horror unfold from Helene should be a wake-up call to the entire weather enterprise that, no matter how good a forecast is technical, the goal is to get people to act on it to save lives.
Scientists/forecasters forecast Helene well, but there is a disconnect between them and people taking action. I have long been a proponent of more research and work on a forecast's communication/action stage. There is a lot of work to do there to ensure that suitable information is reaching folks in at-risk areas from trusted messengers.
The ongoing work in this part of weather forecasting will likely bear much fruit. As always, be sure to have multiple ways to get weather information and warnings and an action plan based on your area's local risks.
The Big 3
There could be tropical trouble brewing in the Gulf of Mexico. However, as of this morning, models are still struggling to fully develop this system. To stick with the point in the introduction, there are many posts from dubious pages on social media claiming a hurricane is coming for Florida. Currently, there is no data to support such a prediction. The best that can be said about this wave is that it will bring heavy rain to parts of the Gulf Coast/Southeast. But as far as it intensifying, the data isn’t fully there on that right now. Conditions aren’t quite as favorable, but this system will require close monitoring in the coming days to see if data changes.
Outside of that, it seems cruel and ironic that the seven-day precipitation outlook for the entire country is amongst the driest of the year. Some rain will undoubtedly fall in the far SE and NE parts of the U.S. — but almost the entire rest of the country looks dry, especially west of the Mississippi. For this storm chaser, I am guaranteed a week of no fall severe weather.
Flash flooding is a significant threat no matter where you live. There have been a lot of posts on social media with an exasperated tone talking about how Asheville and surrounding areas are 2,000 feet above sea level so that you wouldn’t expect a flood of this magnitude. I am not sure where this theory of the case has come from, but in an area that receives nearly 40 inches of rain annually, flash flooding is certainly something you should expect as a real risk. The catastrophic nature of flooding from Helene isn’t typical or expected, but that doesn’t mean these types of events aren’t likely to happen at ‘higher’ elevations. Recent studies have worked to map flooding risk more accurately, and they have typically found more places susceptible to flooding risks than initially thought.
Chase Log
I started the day off on April 30, 2024, expecting a standard boom or bust dryline day. Maybe a storm could go. Maybe it could organize into a supercell. Maybe it would be worth going out. Little did I know this would end up one of my favorite chases ever.
Here's the first part of that day: the surprise tornado encounter near Cordell, Oklahoma.
Science Spotlight
Have you ever heard of the cap? It is an essential piece to forecasting every tornado season on the Great Plains and even into the Southeast.
You can typically identify a cap in a forecast by looking at a Skew-T sounding.
On a typical SHARPy sounding, look for the areas where the dashed white line in the top-left box is to the left of the red line. That is often an area of capping. The bigger that area is, the stronger the cap. In this sounding, there is -316 surface convective inhibition (CIN) and -223 MLCIN. But, it is also important to note that models are imperfect if you only take a single run of a single model to determine this. A skilled forecast will look at multiple sources to determine the strength of the cap, including from actual observed soundings.
As a storm chaser, I look for days with strong caps to start the day but some form of lifting mechanism (usually a small atmospheric disturbance or a glancing blow from a bigger one) to lift and weaken the cap. This ascent allows storms to form, but the cap keeps the weaker stuff in check until the big stuff can get going and take over an environment. These are usually the 'best' chase days for photography.
Titan’s Toolkit
We are often asked what weather model sites we use. Here are our top 3 sites:
If you are interested in learning more about weather models and what we look for, we have a whole playlist on YouTube dedicated to teaching about this.
So glad I found you guys! Great info on wx.