ASA - Rain occuring in below freezing conditions

[bill_rowe 0]

I've recently purchased ASA and I've been very impressed with the visuals and the interface. I am having a small issue with accuracy/realism of the depicted weather. I'm on right now (1/8/2009 19:20 Eastern time, U.S.) Setting up the map view to center on KBOS and the Zoom to 300 miles, I looked at stations around the area.Some of the interpolated stations (example: NH38) are reporting "light rain" even though the surface temperature is -7.1C. Not at all realistic. Is there any way to force precipitation to take air temperature into account? At nearby stations where light snow is reported (Example KBVY) in the real METAR, ASA also has light snow, so it seems to be a problem with the interpolated stations.Any assitance would be appreciated,Bill Rowe

[Mace 1,927]

I've recently purchased ASA and I've been very impressed with the visuals and the interface. I am having a small issue with accuracy/realism of the depicted weather. I'm on right now (1/8/2009 19:20 Eastern time, U.S.) Setting up the map view to center on KBOS and the Zoom to 300 miles, I looked at stations around the area.Some of the interpolated stations (example: NH38) are reporting "light rain" even though the surface temperature is -7.1C. Not at all realistic. Is there any way to force precipitation to take air temperature into account? At nearby stations where light snow is reported (Example KBVY) in the real METAR, ASA also has light snow, so it seems to be a problem with the interpolated stations.Any assitance would be appreciated,Bill Rowe

If the METAR(s) say light rain, then that is what will be depicted by ASA as you know. You are asking if programmatically ASA could be made to force snow or freezing rain (not depicted in the sim) if the temp is below 0 degC? If so, yes I too have wondered about that. It might be a nice checkbox feature anyway. :)I noticed around Detroit the other night, KDTW reported RAIN but the temp was M02 (-2 degC). Sometimes though that is possible in real life, because of temperature inversions...particularly in the winter. Cold air sinks, warm air is above. PRECIP falls as rain, even though it is much below freezing at the surface.

[bill_rowe 0]

If the METAR(s) say light rain, then that is what will be depicted by ASA as you know.

Yes, I understand that, but the station "reporting" light rain wasn't from a real METAR. In the real world, that airport doesn't have automated wearther capability. The weather at that station was listed as interpolated by ASA, so it was ASA code generating the weather at that site, and (in my opinion) there's a flaw with the interpolation that the code would create light rain in an area where the temperature was well below freezing. As far as I could tell, there was no temperature inversion in the area. That type of weather is very rare in wintertime in New Hampshire.Bill

[Mace 1,927]

Yes, I understand that, but the station "reporting" light rain wasn't from a real METAR.

Yes I posted knowing that it was an interpolated station from what you had said.

In the real world, that airport doesn't have automated wearther capability. The weather at that station was listed as interpolated by ASA, so it was ASA code generating the weather at that site, and (in my opinion) there's a flaw with the interpolation that the code would create light rain in an area where the temperature was well below freezing. As far as I could tell, there was no temperature inversion in the area. That type of weather is very rare in wintertime in New Hampshire.Bill

Temp inversions do occur in N.H. although not as often as further south. With that particular storm system it was unusual in the amount of warm air aloft with it (it was briefly 65 degF here at the surface, which is extremely rare for Jan). You do make a good point, like I said a nice option in ASA would be to have a toggle checkbox to allow or disallow rain when air temp is below freezing.

[Damian Clark 1,260]

Great feedback, thank you!