View unanswered posts | View active topics It is currently Tue Oct 24, 2017 1:26 am



Reply to topic  [ 4 posts ] 
models seem not to predict temps my location? 
Author Message
Light User

Joined: Wed Aug 24, 2011 8:12 am
Posts: 3
Location: South Texas
I am located in what is often referred to as Deep South Texas, aka Rio Grande Valley, McAllen. I'm relative new to using f5data, and have noticed that models appear to me to under predict surface high temps for my location. To put it in context, from 01aug thru 24aug, every day the hi T was > 101F except for one day when it only made it to 100F. It cooled the past 2 days with some needed rain, but the big story is that it is now going to be record hot the next 3 days, hi T 104+ range. This morning I ran RUC, GFS & NAM-WRF for Surface Temp valid at 4p this afternoon, and they all cut off the 100 F several counties north of here, and show temp in the 85 - 90 range, and one even 5 F cooler! This is clearly obvious today, but I've seen this under prediction since I've started using f5data. How is it that these 3 models appear to me to have it significantly wrong? Or am I not understanding something? Now seeing that the NWS forecast has cooled it down to 100-102F range perhaps due to rain past 2 days, but still as I'm reading the models they seem to be 10-15F underpredicting? Wondering if there is some "special" model for RGV?


Sat Aug 27, 2011 7:16 am
Profile
Light User

Joined: Wed Aug 24, 2011 8:12 am
Posts: 3
Location: South Texas
ok, I revisited the info I initially posted, AND when I have f5 plot_values_only both NAM & GFS display 99F with 100F not too far north of me, so clearly an accurate forecast. RUC was noticeably cooler but also the RUC data seemed somewhat "disjointed" to me as if the data might be corrupted, but in any event, better understanding how to use the models, and I guess over time, users develop favorite models & indexes for various situations. Next 3 days are a good evaluation as the pattern here is forecast to deviate from the normal SE flow off the Gulf.


Sat Aug 27, 2011 12:21 pm
Profile
Site Admin

Joined: Mon Jul 04, 2005 9:37 pm
Posts: 846
Location: Cambridge, MN
Post 
I wouldn't jump to the conclusion that the data is wrong. It's the exact model data. When comparing what you see in F5Data to forecasts made by meteorologists, there will be discrepancies because everyone forecasts differently, even if they are looking at the same models.

Because you look at a model and it says x value, it doesn't mean that you're going to believe those values are true and that those values make your official forecast. Also keep in mind models update frequently. NAM and GFS update 4 times a day, so the forecast for tomorrow can change drastically from one run to the next.

Contouring any values is bound to lose some precision. If you plot just the raw values its a better 'literal' representation of the forecast. The contoured values have to smooth out the values to some degree in order to have nice smooth lines.

Also note that questions like these should go in the 'F5Data' category.

_________________
Andrew Revering
F5Weather
http://www.f5wx.com/


Sat Aug 27, 2011 2:36 pm
Profile WWW
Site Admin

Joined: Mon Jul 04, 2005 9:37 pm
Posts: 846
Location: Cambridge, MN
Post 
I should also admit that models are incorrect, absolutely. They are never 100% correct, and that's a common problem that meteorologists have to deal with.

This is why we still have meteorologists to interpret the models, change the forecast before it reaches the public. Models especially this time of year are often incorrect, or only reliable out a day or two at best.

In the spring and winter, they are much more accurate. But this is why we have several models to look at to get a better idea of what the computers are thinking. But it always needs to be taken with a grain of salt, and modified with your own experiences and expertise.

Model data comes from government agencies.

_________________
Andrew Revering
F5Weather
http://www.f5wx.com/


Sat Aug 27, 2011 2:39 pm
Profile WWW
Display posts from previous:  Sort by  
Reply to topic   [ 4 posts ] 

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software.