New to f5 data and making my own forecast

[Allan Jeffers]

Looking at the local radar and satellite images when storms pop up in my area is one thing, but now I want to take on the task of making my own forecast. I have GRlevel3 already for when the weather gets active around here but will use TWC or weather underground maps as well. A couple nights ago I became aware of f5 data software so I downloaded it and watched the video and have some general ideas on how to use the software. The problem is, I am not sure what
NAM's, GFS and so on are, or when to use them for what task.

Lets say for example I am off this saturday and wanted to see if saturday was going to be a good day for a thunderstorm was going to develope over, lets say Weld County here in Colorado. What do I need to look at? NAM's? GFS? MesoAnalysis? Then what?

Right now I am using f5 with out a paid subscription, so is it even possible to do a forecast like this?

 

[Bob Hartig]

I've been a subscriber to F5 Data for going on four years now and I love it, to the extent that I finally bought a lifetime subscription. The free maps are nice, but from a storm forecasting standpoint they're limited, and in my opinion are designed mainly to give you a feel for F5 and whet your appetite for the whole enchilada. My recommendation: Get a monthly subscription, try it, and see what you think. The reasonable price makes it hard to go wrong.


However, if you're not yet familiar with the different forecast models, then in my opinion you'd be better off getting the hang of those first before you go shelling out your money for something that's more than you'd know what to do with right now. Here's a quick rundown of the basic models (there are plenty more, but these are the ones you'll most commonly encounter). GFS (Global Forecast System) is a long-range forecasting model that's run four times daily and goes out to 384 hours. (Once you're out that far, though, you're not so much forecasting as fortune telling.) NAM (North American Mesoscale Model) is a medium-range forecasting model, also run four times daily, that goes out to 84 hours. RUC (Rapid Update Cycle) is typically used for day-of-the-event forecasting and is updated hourly. And mesoanalysis per F5 Data is a combination of surface data with RUC that's processed using F5 creator Andy Revering's unique formulations. Like RUC, it is designed for hourly consultation on the day of an event. The SPC has a fantastic mesoanalysis graphics site that you don't want to miss.

If I were you, I'd start by using TwisterData--a great, free forecasting program--and getting a feel for the different models. You've really asked a pretty big question in that it opens up an awful lot of territory. I've just given you a very, super-broad-brush overview; others on this forum can give you more in-depth insights.

Once you've gotten a feel not only for the different forecast models, but also for the parameters they render such as different kinds of CAPE and CINH, lifted indices, moisture, winds, and so forth, then F5 Data will make better sense for you and you'll understand its value. It offers a ton of data, which right now could seem a bit overwhelming to you, but which in time you'll find extremely useful. One thing I love about F5 is that, thanks to a partnership with Allisonhouse, you can configure any of the GRLevelX radar products to display up to six custom-selected forecast parameters right on the radar. Great for projecting what environment a storm is in or is moving into.

That's it for me. I'll let wiser minds than mine add their gold ingots of insight.

 

[Allan Jeffers]

Thanks, Bob!

I will check out TwisterData and keep playing around with the non subsciption f5 software while I continue to learn. I also did stumble across the SPC site

 

[samuel stone]

when disecting an enviroment for tornado favorability the most basic factors you should look for are

1) WIND SPEED AND DIRECTION THROUGH ALL LEVELS OF THE ATMOSPHERE: the type of wind fields most generally associated with tornadic supercells are winds feilds wich increase in speed with height as well as turn clockwise with height (usaully become more westerly) as you rise in the troposphere. these types of wind enviroments will usaully promote supercellular development rather than just your garden variety storm, as well as give you type of wind shear and "twist" in the atmosphere needed for tornadic supercells. you can locate these types of wind fields by looking wind and preassure charts at all levels of the atmosphere i.e. (surface, 850mb, 700mb, 500mb) are the most commonly viewed charts. also you can use parameters such as bulk shear and helicity to measure the amount of shear in the atmosphere.

2)INSTABILITY: tornaddic supercells are usually colocated very unstable airmasses, these types of airmasses yeild the best "lift" or violent upward rising of air needed for robust storms. these storms will generally be positioned in areas of high CAPE (convective available potentail Energy) this is a commonly used parameter to measure instability and it bassically in a way measures the amount of bouyancy in the air available should a forcing mechanism.. (i.e (cold front or dryline for starters) then proceed to lift that airmass. In a basic sense the higher the dewpoints and the higher the temperture the more instability you will have, but for supercell tornadoes it is important to not have more than APPROX. 20 degree difference between you dewpoint and your temperture in a given enviroment.

Now there are far more factors besides these given above that will have an effect on a given enviroments "tornadic potential" but these are just some very basic building blocks to start from, many important variants that determine "tornadic potential" will however tie in to these basic guidlines, I would also like to say that i am not any sort of expert, far from it but maybe these very basic guidlines will give something to build on in your forecasting of mesoscale enviroments. im only trying to help in some small way

 

[Mike Krzywonski]

This page has some good info.: http://weather.adamsphotogallery.com/class/page5.htm

 

[Paul Knightley]

There are no short cuts to understanding model output and how it relates to storm development and morphology. The best thing is to try to read up on as much forecasting info as possible either from the internet or via books and research papers - the library is a good place to start.
However, the basic ingredients you need to look for are: instability; moisture; lift. For severe storms you also need to look for wind shear. Now, your best bet is to look up these terms and try to understand how they all interact together to produce storms. It's not an easy task, I'll admit - but if you want to be able to get to the good storms as often as possible, you need to put in the leg work.

 

[robert duering]

Thank you Allen for asking this question I am completely new trying to comprehend all this also. Im just so new that I didn't feel comfortable asking yet for I am even new to this site.

 

[Allan Jeffers]

I think I bit off more then I can chew with this software... or perhaps put the cart before the horse I am looking at some books now a couple by Tim Vasquez. I think I am going to get "Severe Storm Forecasting" and trying to decide between "Weather Map Handbook" and "Red Book" then perhaps I can figure out the software a bit more.