Scientists Expect Drought in Western U.S. to Continue Through Spring

The ongo­ing drought in large sec­tions of the United States is expected to con­tinue, accord­ing to the lat­est report from the National Oceanic and Atmospheric Administration (NOAA).

The NOAA indi­cated that the drought would likely con­tinue in the cen­tral and west­ern U.S. and may expand across the south and south­east of the coun­try.

One rea­son for the per­sis­tent drought is the con­tin­u­a­tion of the La Niña phe­nom­e­non for the third con­sec­u­tive year, result­ing in drier con­di­tions in the south­ern half of the coun­try, includ­ing California.

On the other hand, wet­ter-than-aver­age con­di­tions are expected in the north-cen­tral and north­west­ern regions of the coun­try.

In its newly released win­ter out­look, the NOAA said warmer tem­per­a­tures would be expe­ri­enced in the south­west, along the Gulf Coast and east­ern seaboard.

La Niña is char­ac­ter­ized by unusu­ally cold ocean tem­per­a­tures in the equa­to­r­ial Pacific. In con­trast, El Niño is char­ac­ter­ized by unusu­ally warm ocean tem­per­a­tures in the same loca­tion.

“During a La Niña year, win­ter tem­per­a­tures are warmer than nor­mal in the south­east and cooler than nor­mal in the north­west,” the NOAA said.

However, the impacts of the con­tin­u­a­tion of La Niña on the pop­u­la­tions and agri­cul­ture are grow­ingly sig­nif­i­cant.

“Drought con­di­tions are now present across approx­i­mately 59 per­cent of the coun­try, but parts of the west­ern U.S. and south­ern Great Plains will con­tinue to be the hard­est hit this win­ter,” said Jon Gottschalck, chief at the NOOA’s Operational Prediction Branch.

“With the La Niña cli­mate pat­tern still in place, drought con­di­tions may also expand to the Gulf Coast,” he added.

The lack of rain­fall has already taken a toll on grain and soy­bean pro­duc­ers in the Midwest. The lack of pre­cip­i­ta­tion has sig­nif­i­cantly low­ered soil mois­ture, pre­sent­ing prob­lems for the cur­rent and future har­vests.

The NOAA report indi­cates that cur­rent drought con­di­tions are the worst since 2012 and will pro­foundly impact sta­ple crops, such as corn, wheat and soy­beans.

In the Colorado River basin in the south­west, thou­sands of farm­ers have protested cuts in water avail­abil­ity for irri­ga­tion due to the low river and reser­voir lev­els caused by the drought. Seventy per­cent of Colorado river water usage is tra­di­tion­ally ded­i­cated to agri­cul­ture.

Meanwhile, the megadrought in California also con­tin­ues to dimin­ish water avail­abil­ity for irri­ga­tion. The Public Policy Institute of California said the pro­longed extra­or­di­nary con­di­tions con­tinue to break records that date back to the late 1800s.

For an agri­cul­tural sec­tor worth $50 bil­lion per annum, expec­ta­tions that the drought will con­tinue through the fol­low­ing spring come as wor­ry­ing news.

Furthermore, research pub­lished in Limnology and Oceanography Letters found that the increas­ing num­ber and sever­ity of heat­waves, which affect farm­ing yields, soil con­di­tions and river and stream ecol­ogy, have exac­er­bated the drought.

Separate research on wild­fires found the drought and heat­wave-fueled nat­ural dis­as­ters have more pro­found effects on the broader cli­mate than pre­vi­ously thought.

The study found that heat and aerosols pro­duced dur­ing wild­fires in the west­ern U.S. may increase the inten­sity of storms in the Midwest.

The heat from the wild­fires impacts atmos­pheric pres­sure, gen­er­at­ing wind that blows atmos­pheric mois­ture and other par­ti­cles east­ward, increas­ing rates of pre­cip­i­ta­tion and hail, which could cause sig­nif­i­cant dam­age to crops.

“This is the first study where we are really show­ing that wild­fires can have a sig­nif­i­cant impact on the down­stream weather,” Jiwen Fan, a researcher at the energy depart­ment, told The Guardian.

However, he added the research would help develop more accu­rate pre­dic­tive mod­els about severe weather con­di­tions caused by wild­fires in areas far from blazes.

• The Guardian
• Phys.org
• Farm Progress