SEPTEMBER 1991:

Temperature: 1.0 celsuis degrees ° a
above normal. CBE

Precipitation: 39.9 mm’ below ES-
normal. c 4r

Sunshine: 25.4 hours below nor- i3P
mal. U a i

Number of days with no sun- Sq
shine: 2 days. 3b
OCTOBER 1991:

Temperature: 1.3 celsuis degrees

91-80 normal

78-79 average
82-83 average
88-89 average
91-92 average

Maan

Minimum
FIGURE 1.
Comparison of the five monthly averages (September - January)

of maximum, minimum and mean temperatures.

Maximum

~ below normal.
Precipitation: 79.7 mm above

normal.
Sunshine: 0.8 hours above normal.
Number of days with no sunshine: 13 days.

NOVEMBER 1991:
Temperature: 1.9 celsuis degrees above
normal.
Precipitation: 199.3 mm above normal.
Sunshine: 45.5 hours below normal.
Number of days with no sunshine: 24 days.

DECEMBER 1991:
Temperature: 5.0 celsuis degrees above
normal.
Precipitation: 335.7 mm above normal.
Sunshine: 21.0 hours below normal.
Number of days with no sunshine: 26 days.

FOR THE WHOLE YEAR OF 1991:
Temperature: 0.7 celsuis degrees above
normal.

_ Precipitation: 557.1 mm above normal.
Sunshine: 34.1 hours above normal.
Number of days with no Sunshine: 109

days.

Monthly and annual records set during
1991: total precipitation for November — 379.6
mm; total rain fall for December — 326.3 mm;
total precipitation for December — 488.1 mm;
lowest last-quarter total sunshine, October--
December — 83 hours total! Lowest
combined November and December

son of several September-to-January periods of
interest and compare them graphically to the
1951-1980 normals for the same five-month
period.

As we compare the evidence in Figure 1, we
see that 1978-79 was cooler than normal, but
by 1982-83 a marked warming trend is evident.
We further note that 1988-89 was slightly
warmer than the El Nino year of 1982-83. But,
really, 1991-92 is the year to remember as it
stands head and shoulders above the rest for
the five-month period from September to Jan-

uary.

Figure 2. compares rainfall, snowfall, total
precipitation and hours of bright sunshine for
the same periods charted in Figure 1.

As we compare the evidence in Figure 1, we
see that 1978-79 was only slightly wetter than
normal with near normal snowfall and bright
sunshine. 1982-83 (an El] Nino year), although
warmer than normal (Figure 1.), was quite dry
and cloudy with well below normal precipitation
and below normal bright sunshine.

In Figure 1, we noted that 1988-89 was
slightly warmer than the El Nino year of 1982-
-83, and we see from Figure 2 that the hours of
bright sunshine are about the same... but the
comparison ends here, as we see from Figure 2.
— 1988-89 was much wetter than normal.

But, really, 1991-92 is the year to remem-

sunshine — 19.9 hours total!

Greatest 24-hour precipitation for 300 -

December — 159.0 mm on December

90, 250+
200
150

It would seem that 1991 will be
a year to remember, but how did it
compare to other years? Especially
how did 1991 compare to other El
Nino years like 1982-1983 or 1988-
1989?
In Figure 1, we make a compari-

100
50

WB 91-80 normal

=) 76-79 average
MMB 82-83 average
WM 88-89 average
91-92 average

SUN (hours)

SNOW (Cm! PCPN (mm)
FIGURE 2.
Comparison of the five monthly averages (Sept. - Jan.} of rainiall (mm),

snowlall (cm), total precipitation (mm) and total hours of bright sunlight

RAIN (mm)

Terrace Review — March 6, 1992