Weather report confusion?

Question

Just now, I checked the weather in Taipei for my trip tomorrow, and here's what I found:

Weather.com
Fri Sat Sun Mon
25/21 25/21 26/21 25/19

Yahoo! Weather
Fri Sat Sun Mon
25/20 25/21 25/21 25/19

CNN
Fri Sat Sun Mon
14/8 17/15 18/16 14/14

I'm terribly confused. Who am I going to believe? Besides based on my experience, none of these are reliable. 3 weeks ago I went to HongKong and the weather I was expecting, which is hotter, since it is turning to summer, was the other way around. Seems like they have a hangover for Christmas.

Answer 1

I just check with the three sites you had given and they seemed to have to come to an agreement.

There maybe many reason why you saw such a difference.

Here is what I found for Friday night through Sunday:

Weather.com
21/25/21/25/21

Yahoo
20/25/21/25/21

CNN
19/25/21/28/23

I also check the following link to see what the GFS (just one of several forecast interational models available from one site I use often. It gives me a three hour time step through the extended period. However, I would caution use of it since based on what I can tell, Taipei seems to be more influence by the local effects which is something a computer model would have difficulty. But based on just that one model, it also agrees with this three forecast are saying. I can not judge the quality since you really need somebody with at least two years of local forecast experience before they usually a pick up on all of what the models are usually right or wrong on.

I did take a peek just for fun at the satellite loop and the GFS forecast graphics and based on what I can tell, having never forecast for that area, the general unsettle weather forecast looks okay. There are some thing I have noticed with a quick look at that one model and the latest satellite loop.

The jet stream is between Japan and Taiwan. Looking at the low levels, the front is also positioned in the same the same way. With the front parallel with the upper flow, the surface cold front shoud not be moving much and will weaken as it will likely remain to the north. This will mean little change in the weather through the first half of the weekend.

What about the unsettle weather. Based on what I can tell. They seem okay too.

But since I have never forecast for that area, I would trust the people who make their living forcasting in Taipei.

A weather forecast is just a best educated guess made at that time. Weather forecasting is much more difficult than most people think. So check the forecast often and do expect them to change...especially in the extended period. I don't think we will ever get near perfect in my lifetime.

Hope you have a good trip.
.
http://wxweb.meteostar.com/sample/sample_C.shtml?text=RCSS#

http://wxweb.meteostar.com/cgi-bin/meteogram/meteogram_celcius.cgi?RCSS

Answer 2

The old professor says: I have given problems similar to this to my meteorology classes in the past. After collecting data over a several month period of time they came up with the conclusions that one source was most accurate in temp predictions, another source did better in precip predictions while another did better in sun/cloud predictions for a three day (72 hr) forecast. The overall conclusion was that different computer models that were used excelled in one area that the others didn't ... and for the sake of accuracy, they found by combining these attributes of the various models they could come up with a better forecast than any of the reporting stations could over 70% of the time. Unfortunately, weather forecasters haven't figured that out yet.

Needless to say, as the forecast got closer to a nowcast, the accuracy for all of them got better.

Answer 3

These forecasts are unmodified products of computer models. Different models produce different results. Each country has its own meteorological service which has forecasts being produced by human beings. These tend to be more accurate than the unmodified computer products. If you want to find out what the weather is doing in any country, look up that country's meteorological office for the most accurate forecasts.

Answer 4

What a tower calls basic vfr,1000 and 3, doesn't mean that you can go fly away vfr. My airport, SBA, is based near the ocean, so if I can do arrive and/or depart over the water then I am ok, as soon as I turn over the congested city then I am not obeying the 1000 foot over a congested area, there for not legal. The aiport goes VFR at 1000 and 3, but that doesn't mean you can go fly away vfr, and I have seen it where the tower gives the ok for the touch and go's but that still doesn't mean it is legal to do so. To make it legal ask for 'special vfr', one can ask for this even when just staying in the pattern to do touch and go's FAR 91.119 gives us some leeway for going below 1000 feet over congested areas for landing and taking off, but I lost the discussion with the FAA guy, about T&G's at 500 feet over the city. I just attended a fantanstic FAA meeting where we went over your exact question. Good luck