th SatialSpanar nabted,
-

Se Ata atts aise Heat i Be oh at nok

‘teaitlin

depth of 3-6 inches.

et
alice

i

5

4

.

digit ia

ebeoshesfle.

PRR ees

It 1s difficult to estimate what the accuracy of these observations was, .

but assuming that the instrument was correct within 0.2° C., that the observer's readings were &
bo

correct within 0.2° C., that neither of these possible sources of error was consistently biased

and that both errors were distributed normally then 9 values out of 10 are correct within 03° BF
Fe and all are correct within 0.7* F.

TABLE 8.

KEITH:

THREE-HOURLY OBSERVATIONS.

See Notes for Table 6.

:

Experienced observers made the cloud and other observations during the following intervalsBF

(times are inclusive): 1200 Aug 18 -- 0900 Aug 19; 1200 Aug 21 — 0900 Aug 23; 1200 Aug 26
=-- 0900 Aug 27;
TABLE 9

1200 Aug 28 —~ 0900 Aug 29;

KEITH:

1200 Aug 30 -- 0900 Aug 31.

1

HOURLY RELATIVE HUMIDITIES.

This Note applies also to Tables 22 and 25.

The three-hourly values (0300, 0600, etce) are based on direct dry-bulb and wet~bulb
readings (Table 8).

rsf

The remaining values are taken from hygrothermograph charts, with ad just- 7

ments in absolute trace readings being made to fit the three-hourly values.

The three-hourly 3

values are al] correct within 6% and 9 out of 10 are correct within 4% (see Notes, Table 4).
For intermediate hourly values, these errors increase to 8% and 5%.

‘

Further, at values in the |

80s there is a small bias -- about 1% -- in the direction of giving values that are too low;

!

while in the 90s there is similar bias of about 22.
Since the hygrothermograph was checked regularly (usually daily and at least every other

‘

day) times are correct within 15 minutes.
TABLE 10.

MACK:

DAILY OBSERVATIONS.

This Note applies also to Table 26.

rig
we OF
ee Og

sm

eg we SS

a

The Notes for Table 6 apply for all items except RR, DDFF, Sea, and Remarks.

Cloud, wind,|

sea, and other observations were made by experienced observers on all dates except August 26th |

through 29th.
RR.

j

Unavoidably, the raingage was not well exposed (see General Notes and Figure 7).

Therefore readings may be in error by as much as 20%, with values probably tending to be too
low when the wind at time of rainfall was between NNW and NNE and too high when it was between|

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