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WISCONSIN CRANBERRY GROWERS' ASSOCIATION
LOCAL FORECASTING OF HIS OWN CRANBERRY
BOG VERY IMPORTANT FOR THE
WISCONSIN CRANBERRY GROWER
By 0. G. MAI.In.. Tomah, Wis.
The forecasts of the 1. S. Weather Bureau together with their daily
weather maps are practically indispensable to the cranberry growers
and this is especially true of the Wisconsin groweis.
There are certain local conditions, however, that often develop un-
expectedly in the Wisconsin cranberry regions and which cannot be
foretold by the Weather Bureau in their morning forecasts, nor even
in their special afternoon forecasts, because these conditions develop
late in the afternoon or early in the evening.
The Wisconsin growers, therefore, need to be especially vigilant on
account of these possible, sudden, unforeseen, local changes and should
accustom themselves to making forecasts for their own individual
locations.
From data gathered over a period of several years at the Cranberry
Experiment Station at Cranmoor, I have devised a simple method of
forecasting minimum temperatures, that I believe can be safely fol-
lowed by any Wisconsin grower who will provide himself with the
few necessary instruments, and familiarize himself with the local
conditions that must be considered in making predictions.
After several years of comparison between the evening dew point
and the minimum temperature of the night following on unsanded
bogs, It was found, that under normal conditions the average range
or difference was about 17 degrees. By normal conditions is meant
a normal barometer and a normal direction and velocity of wind for
the locality. Seventeen degrees was therefore adopted as a constant
or basis from which to figure the minimum temperature.
For each tenth of an inch that the barometer is above normal,
three degrees should be added to the constant, and vice versa. For
each four degrees that the daily maximum thermometer registers be-
low 75 degrees, on a clear day, with a westerly, northerly or northeast
wind prevailing, and with a stationary or slowly rising barometer, add
one degree to the constant.
Other local conlitions that should be considered, but which require
local experience to be admitted in the calculations are; condition of
the sky, regularity or irregularity of the wind, presence of fog, and
peculiarities of it, presence of a bright Aurora in the northern skies,
.       inactivity of insects and frogs.
To forecast satisfactorily a grower should possess:
1. Maximum Registering Thermometer exposed in a standard
shelter.
2. One minimum registering thermometer exposed in a stan-
dard shelter.
3. One minimum registering thermometer at the coldest place
known in the cranberry bog or adjoining it on the wild marsh.
4. One barometer (registering barograph is best) which may
be kept in the house or on the porch.
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