Sunday, April 10, 2016

Longer Range Rainfall Amount Forecast

One of the reasons you don't see snowfall amounts beyond three days or rainfall forecasts beyond five days on this blog very often is because -- in spite of our major progress in weather forecasting the past decade -- they are still not very consistent.

Here is an example. The U.S. GFS's ten-day forecast of rainfall centered on Kansas:
click to enlarge
And, here is the, often more accurate, European model for the same period as above. It is significantly different.     

Meteorologists try to get around all of this by running a bunch of models together and averaging them. This is the European ensemble run from last night's models.
The ensemble pattern, like this morning's individual European model result, shows lesser rainfall amounts in northeast Kansas and heavier amounts in southern and western Kansas which, more or less, confirms the pattern in both of the individual GFS and European models from this morning. Got all that?

So, what can we say? I am confident of substantial rains (≥1.5 inches) over all but the northeast 1/5th of Kansas over the next ten days. If the low pressure system after Day 5 starts slowly drifting over the Plains, as some of the models are showing, then the heavier amounts shown in the European model may well come true. If so, it would be a godsend for the 2016 winter wheat crop.

2 comments:

  1. Well there's two storms coming - the one that isn't as big that is tonight (Denver) into tomorrow (assume Kansas), then the much bigger one next weekend which even the KDEN long range forecaster is starting to sound the alarm about so to speak. Obviously the models won't get a grip on next weekend's system until it actually comes ashore.

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  2. Always enjoy your in-depth look at the weather, thank you for posting.

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