26 May 2015

An El Nino connection to the floods in Oklahoma and Texas?

Posted by Dan Satterfield

Rainfall in the last 30 days from the Oklahoma Mesonet. Some areas have   exceeded two feet!

Rainfall in the last 30 days from the Oklahoma Mesonet. Some areas have exceeded two feet!

There were more flash floods across the Hill Country of Texas into the eastern part of the state as well on Monday, and a Flash Flood Emergency was declared in the Austin area. Now, look at the sea surface temperature anomalies for the globe right now, with the signs of a developing El Nino (the warm water off south America stretching westward along the Equator), and also note the warm waters in the Eastern pacific off the coast of North America. This unusually warm water pattern in the NE Pacific has been present for almost two years now, and it’s almost certainly a player in the drought in California, and may also have a lot to do with the previous two cold winters is the Northeast and Midwest, as well.

From Weatherbell. Current sea surface temp. anomalies.

From Weatherbell. Current sea surface temp. anomalies.

Every El Nino is different, but they tend in general to bring heavy rains to the Gulf Coast, and (based on new research) the threat of severe storms and tornadoes is actually higher in La Nina years, but while there have been some tornadoes in the Plains over the past 30 days it is the unrelenting flooding rains that are the real story. El Nino’s tend to have their main impact during the Northern hemisphere winter, but the map below courtesy NOAA, shows that Texas and the Gulf Coast have wet springs in El Nino years. 

MarchOutlook_fig01_620

 

Below is the forecast for June from the NOAA Climate Forecast System model. This is a coupled model that allows interactions between the ocean, land, and atmosphere, so in other words it is taking into account that warm water in the Pacific. It is also taking into account the warmest global sea water temperatures on record as well. NOAA reported that April’s ocean temps. were the warmest on record, even passing the previous record year of 1998 (which, by the way, was the year of the super El Nino).

NOAA CFS Model for June.

NOAA CFS Model for June.

As we say Okies say…

All this ain’t good.