weather forecast question



I had started an earlier thread about weather forecasts ( … p?p=111438 ). I got some very useful feedback there, and I have a short follow-up.

I am trying to identify which of the short-range (3 day ahead) NOAA forecasts people use for their flight decisions:
(ii) Eta MET MOS (
They contain almost identical weather conditions, and I could not find much about either at ).

Any help in differentiating between the MOS and MET reports would be most appreciated!


I know this doesn’t help as far as the methods you’ve mentioned, but 3 days out, I usually will look at the prog charts on The one I find most useful that far out,even though it seems optomistic on the third day compared to less than a day out, is the NWS graphical forecast It is not on but rather the NWS site. It allows you to select a time and scroll over the type of info you want and it displays it on the map. Since the forecast 3 days out is so variable, this is really as in depth as I get. I know many people who simply look at local news or Weather Channel info that far out. The idea at that time is there a chance of precip,what general temp is it going to be etc. VIS and ceiling and winds to an extent are pretty much useless that far out.


I’m with pfp213-

But three days out I have no clue where I’m going. And the only thing that’d stop us is less then 4000rvr or a hurricane :open_mouth:


Are you sure we don’t have the same job???


I’m with pfp213

Correction: pfp217


TS with tops at FL800, flooding and x-winds of more then 45kts- If you’re dieing we’re flying! Red line or Parking brake, no in-between

The most important thing is… It’s my week off and I’m watching football (and Becky hasn’t said a word) 8)


today is a good example. Here at SPI yesterday we were issued a flash flood warning. The remnants of TD Hermine were expected to drop 1-3 inches of rain here at SPI. Now, 30 hours later, the northern edge of the remaining rain from the TD is about 1 county away from SPI,and it’s dissipating. It doesn’t look like we’re going to see any precip at all. The jetsteam pushed it a bit further east, and now it’s losing it’s moisture. 30 hours ago it looked like we were going to have an all day rain event today.
That’s 1 day out. It’s good info, but really1-3 hours is when its starting to be reliable. That’s not a knock on the forecasters, it’s just that variable.


Thanks for the comments everyone. It sounds like the three day forecast is not used too much, but I would imagine some folks are planning their trips a few days out-- if anyone has compared the MOS and MET reports and can list their preference, I would greatly appreciate it.

Also thanks pfp217 for suggesting the NWS graphical forecast: really nice site. I unfortunately have not been able to find archived NWS forecasts as far back as I need so I have not been using them.


I don’t think too many flight schools are teaching how to use MOS and MET forecasts.



help any?


Thanks for the link Allen. Yeh, I had seen this page already but the information on numerical models is either very basic (how to read the charts) or aimed to specialists in with atmospheric sciences training (which I do not have :frowning:).

Anyway, I guess this is a bit too off-topic for the forum. I will get in touch with NOAA and see if they can help differentiate them.

Again thanks to everyone for the comments,


MET MOS is the name of a forecast product based on one of the short-range models that run at NOAA central computing facility.

MOS (Model Output Statistics) is a technique to extract forecasts of surface-based weather elements from a numerical weather model. Believe it or not, many numerical models do not directly forecast many aspects of what is considered ‘weather’, like sky condition (CLR, SCT, BKN, etc), or ceiling heights. The MOS technique can correct for systematic weather model errors and generate probabilistic information as well.

So when you mention “GFS MOS”, that is a forecast product that uses the Global Forecast System (GFS) weather model as input. Likewise, NAM MOS is a forecast product that uses the North American Model (NAM) as its input.

Both forecast products (or bulletins as they’re called) have nearly identical formats, but depending on the situation, they can have some, sometimes even significant, differences in their forecasts because the models disagree as to what will happen. Weather consumers often consult both ‘flavors’ of MOS in their decisions as the NAM and GFS weather models have their strengths and weaknesses that are sometimes complementary.

I hope that helps you, Professor,




Sorry I was away from this thread and did not see your response until just now.

Thanks for your really detailed reply: this gives me a very useful foundation for understanding these weather products (you basically schooled me on the basics: and I am the professor??? well those who can’t do teach :slight_smile:)


Didn’t mean to be pedantic but glad I was able to provide some clarity regarding these products.