Tweet
Roughly 50 years of wind data was looked at at Dodge City, Topeka, Wichita, and Goodland.
All sites showed a decrease in wind speed in tenths of m s^-1 (simple least squares regression) over the time frame from 1965 till the mid-2000's when a rather sharp increase in springtime wind speed was noted. A 50-day moving average was used to smooth out the data and to include seasonal variations in wind speed. The amount of events that would qualify in the 95th percentile of wind events was noted as well. Most of these events were either southerly or NWerly based. This makes sense as strong wind events would be before and after the passing of a surface cyclone.
Unfortunately widespread surface pressure data is not easily available so I couldn't see if the pressure gradient across Kansas is increasing in unison with the wind speed (theoretically it definitely should). My thinking for this increase is an increasing temperature gradient between the high plains and the rocky mountains leading to stronger lee-side cyclogenesis. Another possibillity, and one that should be looked at as well is the strengthening of Canadian High Pressure systems coming on the backside of the low.
This wind increase seems independent of any major Teleconnections (El Nino, etc). Though more analysis with this is needed as well.
This data points out an interesting problem with Regional Climate Models as most models increase the wind speed across the Great Plains, but also increase the precipitation along with it. That hasn't been happening as the GPlains has seen some of the more devastating drought in recent history.
All sites showed a decrease in wind speed in tenths of m s^-1 (simple least squares regression) over the time frame from 1965 till the mid-2000's when a rather sharp increase in springtime wind speed was noted. A 50-day moving average was used to smooth out the data and to include seasonal variations in wind speed. The amount of events that would qualify in the 95th percentile of wind events was noted as well. Most of these events were either southerly or NWerly based. This makes sense as strong wind events would be before and after the passing of a surface cyclone.
Unfortunately widespread surface pressure data is not easily available so I couldn't see if the pressure gradient across Kansas is increasing in unison with the wind speed (theoretically it definitely should). My thinking for this increase is an increasing temperature gradient between the high plains and the rocky mountains leading to stronger lee-side cyclogenesis. Another possibillity, and one that should be looked at as well is the strengthening of Canadian High Pressure systems coming on the backside of the low.
This wind increase seems independent of any major Teleconnections (El Nino, etc). Though more analysis with this is needed as well.
This data points out an interesting problem with Regional Climate Models as most models increase the wind speed across the Great Plains, but also increase the precipitation along with it. That hasn't been happening as the GPlains has seen some of the more devastating drought in recent history.
Comment