World Grain - March 2023 - 72

Transition from La Niña to
El Niño may be quick
Change could cause weather problems in many areas around the world
by Drew Lerner
L
a Niña is weakening and expected to completely
dissipate this spring. Some computer forecast
models have been suggesting that a quick transition
from La Niña to El Niño is possible over several
months this spring and summer. In the past, some of
these quick transitions have left the atmosphere a little
confused, leading to weather problems in many areas
around the world.
The loss of La Niña in this coming Northern
Hemisphere summer is likely to induce some areas of
dryness in Indonesia, Malaysia, Philippines and mainland
areas of Southeast Asia. Portions of India also
will experience lighter-than-usual precipitation. Most
of the lighter-than-usual rain will only raise some concern
about dryness and crop production, but it normally
takes a full blown El Niño event to induce a serious
bout of drought in the tropics.
The
US National
Oceanic
and
Atmospheric
Administration (NOAA) has a model that predicts
ENSO (El Niño/Southern Oscillation) conditions out
several months in time. The latest NOAA ENSO forecast
model has suggested El Niño may evolve in June
and be influencing the world from July through the end
of this calendar year. World Weather, Inc. believes the
transition from La Niña to El Niño is advertised to be
too aggressive, but if the forecast verifies there may be
several areas around the world that could experience
poor crop weather during the second half of this year.
The withdrawal of La Niña and return of neutral
ENSO conditions usually brings on lighter-than-usual
rainfall in Indonesia, Malaysia, Philippines, Vietnam,
Laos, Thailand, Cambodia and parts of India. The dryness
is rarely a serious problem unless a full blown El
72
Niño event evolves. There is potential for El Niño conditions
later this year, but World Weather, Inc. believes
the transition advertised by NOAA is suggested to occur
a little too quickly.
In the past, there have been some interesting dryness
issues that have evolved across North America when
a prolonged La Niña like that of the past few years is
quickly followed by a moderately strong El Niño.
Weather in North America during March of those years
often is mixed with portions of the Midwest, Delta and
southeastern states getting a little more than the usual
precipitation while the southern Plains, Atlantic Coast
states and far western United States is a little drier biased.
Comparisons to 1976
US weather in April becomes a little more interesting
- or at least that is what has happened in the past.
There have only been a few occurrences of rapid transition
from La Niña to El Niño after a prolonged La
Niña event. One of those years was 1976, and last
year's weather was similar to 1975 as well as 1956 and
2000. In 1956, La Niña already was dissipated midway
through the fourth quarter of that year, which is quite
different from that of this year in which La Niña was
weakening, but still present. The multi-year La Niña of
1998, 1999 and 2000 was followed by neutral ENSO
conditions in 2001. That suggests that if the NOAA
forecast model is correct, the quick transition moving
from La Niña to El Niño would be a good match for
the year 1976.
Spring 1976 was favorably mixed with periods of
warm and cool weather and periods of rain and dry
conditions. March was wetter biased in the northern
March 2023 / World Grain / World-Grain.com
©Andrey VP-stock.adobe.com
http://www.World-Grain.com
World Grain - March 2023

Table of Contents for the Digital Edition of World Grain - March 2023
