Irrigation and severe weather

[Justin McGinley]

So does anyone think that Irrigation has an impact on severe weather? Here in nebraska we have planting going on now and also farmers are putting down fertilizer. We have not had a good soaking rain here in I think almost a month. We are in the D-0 for drought actually. So the farmers have started up the pivots not only to soften the soil for the seed to break through but most of that fertilizer takes about 3/4 to an 1in of rain to activate. So say if does not rain for the next couple of weeks and the pivots keep making circles. Does all that moisture from the ground have a impact on any severe that might happen come this spring?

 

[Jeff Duda]

Short answer: probably, yes.

Long answer: if enough farmers put that kind of moisture in the soil, there will almost certainly be some degree of increased evapotranspiration that happens as a result, thus generating latent heat flux and moistening the surface layer. Could add a degree or two to surface dewpoints or a few tenths of a g/kg to the afternoon mixed layer mixing ratio.

But you would need nearly every farmer in a fairly large region (say, a square 200 km on a side) to do this, and the effects would be most prominently felt wherever the synoptic scale flow advects that low-level moisture, so it may not remain over Nebraska.

 

[TJKLECKNER]

I remember the humidity/moisture the lush green Iowa corn crops produce, had to contribute a little

 

[rdale]

See Episode 2 of Rich Thompson's tornado videos - he addresses that explicitly.

 

[TJKLECKNER]

See Episode 2 of Rich Thompson's tornado videos - he addresses that explicitly.

Ah yes! Evapotranspiration