Friday, October 18, 2024

What's with the drought map & a look ahead

When the drought map comes out on Thursdays, our team is quick to publish it in many spots (our Storm Team 12 app, Facebook, X, website, and of course all over TV). Since we aren't getting out of drought anytime soon, I thought it was important to address a question that keeps coming up:

Why doesn't the drought map look worse when we are 9-10" below on rainfall? Or, Why doesn't the map represent my area differently?

I wish I had a good, concrete answer for this, but the latest map does leave me a little confused too. I believe the biggest reason the map doesn't show "severe" or "extreme" for south central is because our vegetation health improved a bit after the late September moisture (remember much of central and southern Kansas had .5-1"). Our evaporation rates have slowed lately because of the cooler weather, which might also explain why conditions aren't displayed differently.


Here's what we know about each drought map that is released:

  • The weekly cutoff for rain is Tuesday morning (any rain on a Wed/Thu) is not considered
  • It always looks back in time - it's not a forecast for anything incoming
  • It almost never shows worsening drought by more than one category per week. However, conditions can improve by more than one category if enough rain falls.
Each weekly map builds off the previous week, so in most cases, you probably won't see huge changes week-after-week (again, unless there is major rainfall that occurs). The drought map is NOT a model, but rather a blend of three important factors (which you can actually be a part of - read on):

  • Impacts - (agriculture, wildlife, land use, etc)
  • Feedback from local experts
  • Physical data at different time scales - (winter vs summer, fall vs spring)

Other inputs include streamflow, reservoir levels, evaporative demand, temperatures, and vegetation health. Most of us look strictly at rainfall numbers, but there isn't just one piece of this that tells the whole story.

If you'd like to submit photos and input to the drought map authors, you can do so by emailing: droughtmonitor@unl.edu


What's next??

My last update suggested the upcoming 30-45 days were encouraging. I still feel that way about the period between Halloween and Thanksgiving. Most models indicate better potential of low-pressure systems coming into the western US, which would at least yield rain chances (something we haven't had much of at all lately). Over the past month, it's not that we are getting missed by the rain - there just hasn't been any rain to forecast. I'm not making promises that drought improves drastically, but it would be nice to just get some rain again, and I think those chances could be more timely moving into November. Be sure to check back. 

Thanks for reading!

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