La Nina is finished, National Weather Service says
The National Weather Service announced Thursday that the two-year La Nina weather phenomenon is over. Climatologists believe that could be good news for drought areas of the South and hurricane areas along the coasts.
La Nina is the cooling of the central Pacific Ocean, the opposite of El Nino, which is the phenomenon of the warming of the water in the central Pacific. La Nina’s greatest effects are seen during the winter months, usually triggering drought in the southern U.S. and increased rainfall further north. Historically, La Ninas also produce more hurricane activity in the Atlantic during the summer months. Global temperatures are cooler during La Ninas, especially in the tropics.
To drought-stricken areas such as West Texas, the end of La Nina is welcome news, though meteorologists question whether it is now too late in the season to help the moisture outlook. Eastern Texas received much-needed moisture early this year, but the western half of the state remains locked in an intensive drought. Drought conditions have also intensified in much of the Southeastern U.S. this spring.
The National Weather Service also released its U.S. Seasonal Drought outlook for May 3 – July 31, which calls for the drought in western and south-central Texas to persist. Ditto for drought conditions in Georgia and South Carolina.
According to the NWS, “Some improvement can be expected across the drought areas of the central and southern high Plains, while drought is expected to persist or expand across parts of the West along with western and south-central Texas.”
During the early spring, drought areas expanded while ongoing drought intensified across the interior Southeast due to a lack of adequate precipitation (departures of 2-4 inches below normal), above normal temperatures, and increased evapotranspiration rates, the NWS said.
“Mostly dry weather coupled with record heat (maximum temperatures into the 90s) during the first week of May is expected to result in worsening of drought conditions across Georgia and South Carolina,” NWS predicted. “Persistence is forecast for this area of protracted drought across most of Georgia and South Carolina where no wet signals are apparent among precipitation tools at the seasonal time scale.”
In contrast, drought improvement was noted across southern New England and southeast Florida. Since precipitation signals are weak on the seasonal time scale, this outlook is based primarily on short to medium range forecasts and climatology.
Click here for this week's Drought Monitor report.