Dynamic Weather – Now Available in Flight Sim World

[A32xx 129]

I've just completed a summer day flight from Carlisle to Leeds/Bradford in the UK with Dynamic Weather, and had the "reset the Altimeter by pressing B" message on screen three times. It was fair weather with scattered clouds but much more turbulence than before - it really "felt" like flying a light aircraft (I was in the Just Flight Arrow) and there was no FPS hit either. I'm looking forward to setting today's date and seeing what happens... great fun so far, well done and thanks to all at DTG!

[carbonbasedlifeform 179]

7 hours ago, ca_metal said:

Dynamic weather, it will change procedurally based on DTG's data, and their data is based on the historic weather. Live Weather is something for the future, but they are already looking into it.

Which historic weather is it? Same day different year? 

[scotchegg 4,169]

Won't be able to test this out until tonight, but as they're using historical data, this means weather conditions will be appropriate for the season selected, right?

[theohall65 64]

9 hours ago, AndyUK said:

I've got the update but I can't find a way of getting a report showing, or hearing, the weather at the start or finish airports set by the dynamic weather system.  Is there a way?  After all it is rather important to know what you're getting into before you take to the air!

This is probably stupid, but what about tuning the nearest ATIS?

[AndyUK 26]

Thanks for the tip.  I did think of that but at EGBB which has ATC there's no option to tune ATIS from the ATC pop-up.  Perhaps if you could find the ATC frequency and tune it directly it may then work but how to find the ATIS frequency?  At EGLL there is the option to tune ATIS and that gave seemingly accurate information.  But that leaves a gap at places with no ATC / ATIS, at least if you set your own weather you know what runway to use etc.

[theohall65 64]

VHF / UHF Airband Frequencies in use within the U.K.

http://www.javiation.co.uk/vu.html

[AndyUK 26]

Thanks for that link.  Hopefully we won't have to wait too long before that info can be accessed from within the sim as in FSX for example.

[ca_metal 2,015]

On 01/02/2018 at 5:52 PM, carbonbasedlifeform said:

Which historic weather is it? Same day different year? 

If I understood right, Dovetail collected Weather Info of each area in the world and TrueSky is collecting this info to generate the dynamic weather, maybe historic weather wouldn't be the best way to describe it, what I meant is: If the area you are flying rains a lot, TrueSky will probably make it rain in there. 
 

[jcomm 5,890]

Yep, I believe it is more like a "Weather Theme" approach, in the "Global"....  I don't know how they built their Weather Themes database, but I guess probably based on day of the year, and then on representative METARs for such a situation.

I don't know how they plan to implement what we call "real world weather", but I was always an advocate of a Global Weather Model independent of real life, based on a Global Weather Model engine, feed with good "themes" and options for variability ( anomalies like we call it in Meteorology ).

I guess, after reading a PC Pilot  article on the development of the upcoming Bush Flying sim "Deadstik", that this was exactly their approach.

It is also somehow the approach followed in Aerowinx PSX, although there the Global Weather Model, a quite sophisticated one, blends with rw METAR data if we so want.

[MDFlier 2,031]

My interpretation is that the current "dynamic" weather is based on static METARS assigned to the various weather stations in FSW. As we fly near each station, the weather morphs from what it was at the last station to the weather at the new, closest station. Implementing true "real world" weather from that point is a simple matter of putting in a mechanism that will "install" the current real world METARs to the stations in FSW. All of the heavy lifting is in making FWS build an accurate representation of the weather from a METAR. Once they have that, simply updating the METARs at the weather stations to reflect the actual current weather is the easy part.  

[Murmur 3,941]

2 hours ago, MDFlier said:

All of the heavy lifting is in making FWS build an accurate representation of the weather from a METAR. Once they have that, simply updating the METARs at the weather stations to reflect the actual current weather is the easy part.  

I thought the same thing. Although, going from localized but static weather to dynamically changing weather would require a further step. Even if it interpolates between different METAR stations, a 100% complete weather system would also need to interpolate between METARs from the same station evolving in time (FSX weather legacy system did that, sort of). However I presume that is the long term goal of DTG.

 

[MDFlier 2,031]

I am pretty sure that they already implemented the interpolation between stations. That is how they are accomplishing "dynamic". Otherwise, we would see one type of weather as we passed within a weather station's range, and it would immediately switch to different weather as you passed into the next weather station's area. It seems to me that the conditions are changing gradually as I fly from one weather condition to another. I don't feel like it has been turning off the old weather and then turning on new weather. The Kahului Air missions are pretty good examples. The 3rd or (and) 4th flights have some pretty dramatic cloud cover changes as the flights progress.

FSW is definitely starting off with much better weather "bones" than FSX did.   

[Murmur 3,941]

35 minutes ago, MDFlier said:

I am pretty sure that they already implemented the interpolation between stations. That is how they are accomplishing "dynamic". Otherwise, we would see one type of weather as we passed within a weather station's range, and it would immediately switch to different weather as you passed into the next weather station's area. It seems to me that the conditions are changing gradually as I fly from one weather condition to another.

From their explanation, there's no localized weather in space right now. They interpolate the weather over time (not over space) depending on the nearby METARs, but then the weather is identical at every point in space (i.e. all around you). But their stated long term goal is to have localized weather, i.e. weather interpolation not only in time, but also in space, so that weather fronts are actually depicted.

[ca_metal 2,015]

4 hours ago, Murmur said:

From their explanation, there's no localized weather in space right now. They interpolate the weather over time (not over space) depending on the nearby METARs, but then the weather is identical at every point in space (i.e. all around you). But their stated long term goal is to have localized weather, i.e. weather interpolation not only in time, but also in space, so that weather fronts are actually depicted.

It doesn't change based on time, it changes based on time + area you are flying over. Each area has it's own "weather station". As said by Stephen Hood:

Quote

 

With Dynamic Weather enabled, your flight from departure to destination will 'read in' the weather strings from nearby weather stations and determine the conditions. So if you were to travel, for example, from Coventry airport to Heathrow, you could take off in overcast conditions with light rain and arrive at Heathrow in sunny conditions with very few clouds.

En route, the engine will pickup other nearby weather stations and will, after a period of time, try to transition to the visible weather to those settings it has been fed. There is a cycle which waits before reading new conditions (so as not to be constantly transitioning as you fly within reach of lots of stations) and a transition time whenever a change is initiated. The conditions slowly unfold and do not 'jump' from one to another.

 

Source: https://live.dovetailgames.com/live/flight-sim-world/articles/article/what-is-dynamic-weather

[jcomm 5,890]

I'd say, just as Murmur described, they're presently using pretty much the same approach followed, for instance, by ELITE, when we download METARs in that sim, although in ELITE we can use historical METARS, or present conditions... If present conditions are chose, then it's the vpilot responsibility to re-download METAR data along the flight, or the observations will be frozen in time along the whole flight.

METARs are downloaded for a collection of hours around the start time of the flight. 

Along the flight time and space interpolation take place, in such a way that the program has to blend and phase in / out the data from nearby stations, with special care taken with pressure, then temperature and visibility, then cloud cover, and so on, but, at the same time the present time and position of the aircraft are the variables taken into consideration for that interpolation.

Probably when we start a flight in FSW, on a given date, the collection of World METARs is such that each station has entries for all hours, or half-hours, an the closest match is the one picked as the aircraft approaches a given collection of nearby stations.