The Rural Voice, 1989-05, Page 38M
y editor has two
choices each month
when I send her my
article. One is to use my
"smiling" picture if the article
is of an upbeat, happy nature.
The second is to use the very
serious one if the article is of
a dark and ominous nature.
You're looking at the dark one, and
for good reason. I haven't much good
to say about the weather.
As I write this (April 13), the
ground is covered in heavy wet snow.
All you boys courting your new love,
oats, are wishing it were in the ground.
By the time you read this, I hope they
have been sown, yet I'm not holding
my breath. Why? The climatic depar-
tures from the usual that began last
year are showing no signs of abating.
We are all aware that many areas
of the U.S. and Canada are short of
water. The Palmer drought index
shows serious deficits in west -central
Illinois and eastern Iowa, the heart of
the corn belt. California and New
York are about to ration water to
households. California may have
trouble getting enough irrigation water
and parts of Texas are already dry and
getting drier. As well, Western
Canada is too low on subsoil moisture
for a good wheat crop.
The winter in England, France, and
the Soviet Union has been ominously
warm, much like 1975. China may
well suffer the same combination of
drought and flood as last year.
The last year of the decade will be
one to remember. All the main factors
that determine the weather of the
northern hemisphere are north of their
normal position: the polar jet stream,
sub -tropical high pressure systems,
and inter -tropical convergence zone.
The shift has brought a warm
winter to the U.S., western Europe,
and the USSR. This will be Tess than
FORECAST:
� s r i `I
[HIGH PRESSURE CENTERS OVER THE USA]
11)
WEATHER
WORRIES
Mervyn Erb is an independent
crop consultant and agronomist.
ideal for northern
hemisphere mid -latitude
countries, including
Europe, China, the U.S.,
and Canada, which can
expect hot weather and
insufficient rain. The
strong high pressure system
now affecting southern
Europe usually does not appear until
summer. I've heard that the Italian
wheat crop, for example, is already
stressed from lack of rain. According
to climatologists, the closest parallel
year was 1975-76.
The drawing shows the present
pattern, which is about three months
ahead of schedule. Usually in January
and February the jet stream enters the
U.S. in central California and moves
east over the southwest plains and
along the Gulf states as either the
polar or the sub -tropical jet. The high
pressure systems are usually well off-
shore and to the south.
This year the Bermuda and
California highs are already on land,
forcing the polar jet far north of
normal and bringing the eastern half
of the country warmer than normal
temperatures. The large north -south
arrow shows the path of the moisture
coming into Texas from the Gulf and
moving up the Mississippi Valley into
the Ohio Valley where it meets the jet
stream, producing rain and floods.
To us in the Great Lakes Basin
area, this means a cool and wet March,
April, and May. So far, our April
precipitation is almost double that
of April, 1988. The only good thing
about this is that late -season frosts (as
in 1988) are unlikely.
The pattern shown in the diagram,
which brings moisture to the eastern
half of the corn belt, will continue
until the Bermuda high grows large
enough to cover the Gulf. The small
open arrows show that, when the Gulf
36 THE RURAL VOICE