As the season takes off I keep reading comments about "SPC Chasers" as if they aren't "good enough" as compared to the "experts" that use model data to do their own forecasting. For those of you newbies, SPC is the "Storm Prediction Center". This topic keeps popping up in various places, including a photo on Facebook I just saw posted of a dog at the computer and saying "I have no idea what to do"...representing "SPC Chasers" if the SPC website was unavailable.
|SPC 1630 Convective Outlook for today|
BUT, I do think it is necessary to be able to interpret radar and UNDERSTAND the storm structure and what is happening in the sky when storms do fire. This is critical in staying safe and chasing smart. So, if you are relying on SPC for your forecasts and targeting, please at least learn about the storm and what you are looking at (beyond the tornado!). Take a Skywarn class, complete some online training, read books, and most importantly...go chasing with experienced, knowledgeable chasers who will be willing to help you learn. I did. My first chasing was with experts in the field. And even though I already took the classes and understood the graphics, the structure, the features, the models, the radar, etc....it was a completely different experience being in the field. I was grateful for being out in the field with true experts and I learned so much.
Just so you know where I'm coming from...I have a B.S. Degree in Chemistry and Biomedical Science. I also took several college Meteorology courses, including forecasting...along with a couple extra specialized severe storm forecasting workshops/ classes....from Tim Vasquez and College of DuPage for example. And it all makes sense to me. In my forecasting class with Bob Weisman we had to hand plot the weather maps, surface obs, boundaries, etc. He worked us hard and it was fun! I loved it all.
So, yes, I can and do sometimes do my own forecasting using the various models available on the internet (GFS, NAM, RAP, HRRR, etc). Usually I just look at a few key parameters and determine whether I think the coming day(s) are looking good enough to chase. But this is usually just a validation of what SPC is already saying. So, honestly, I usually just rely on what SPC has to say for the coming few days....until the DAY OF....then it's time to do some real-time data analysis.
|Real-time surface observations today in the slight risk area.|
If SPC has a slight risk that covers 11 states (yes, 11!), as they do today (see map at the top...even though some of those 11 states are only little portions of the state), how do you decide where to target if you don't know much about the science and how to read model data? Ok, yes, SPC does specify what areas have a higher probability of tornadoes in their discussion and even more specifically in an MD. But, this can still cover hundreds of miles of territory. To increase your odds of intercepting the best storms of the day it is important to do some of your own data analysis. Even if you decide to only use the SPC Mesoscale Analysis page, you will need to understand the graphics, what parameters to look at and what to look for.
Personally, on the BIG day, the CHASE day, I use 3 main things:
1. Real time data (surface obs, soundings, satellite, radar, etc).
2. HRRR model runs (where is the model initiating convection?)
3. SPC outlooks, mesoscale discussions, and watches
I personally don't use SPC Mesoscale Analysis graphics very often, but I do sometimes. If you do, be careful of "targets" on some of the composite graphics, such as the Supercell Composite. These are useful in some regards as they are combining many parameters to show where conditions are coming together best for supercells, BUT there are other factors to consider. The target on the graphic may be quite a bit East of where the actual convective initiation will take place....or it may be highest where the CAP is also strongest so nothing will actually fire there. Again, it's about understanding the science of what is happening and how to use the model data and graphics you are looking at in order to pick the most accurate target (which can still be wrong...because there's always a factor of luck and timing involved!).
Hey, if you're an "SPC Chaser" I still love you, you're still awesome, we share a passion for crazy weather! I love SPC and I use their tools all the time. Please just be sure you understand the sky, what you're looking at, the dynamics and structure of the storms (particularly supercells!) and how to navigate safely around them. If you're new and want to learn please reach out to us or other chasers. We are happy to help!
See you under the meso!
|Image copyright Melanie Metz/ TwisterSisters.com.|