15 June 2015

Severe Flood Threat for Texas and Oklahoma Rising

Posted by Dan Satterfield

Estimated rainfall from the NOAA Hurricane WRF Model.

Estimated rainfall from the NOAA Hurricane WRF Model.

Virtually all of the global and regional numerical weather models are showing the potential for very heavy rainfall from what will soon be Tropical Storm Bill in the Gulf. Even if this region had not had historic flooding in May, this would be a big deal, but with the soggy ground, we are now looking at the potential for a very severe and costly flood event. There are some indications that the heaviest rains may fall in almost the exact same areas that had the wettest May EVER, a few weeks back,


Andy Freedman at Mashable has a good explainer of the Brown Ocean Effect. This happens when a tropical system passes over very wet and very warm ground. It is rare, but it can actually cause a tropical system to maintain strength and there have been cases where the cyclone continued to strengthen. Dr. Marshal Shepherd (who is past President of the AMS) co-authored a paper on this in 2013 along with others and NASA has a good summary here.

Look at the map below and you can see how much rain has fallen over Texas and Oklahoma over the past 30 days.

from the Advanced Hydrometeorological prediction Service (NOAA)

From the Advanced Hydrometeorological Prediction Service (NOAA)

Late satellite image courtesy of the CIMMS folks:

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