La Crosse Technology WS-1613-IT Weather Forecast and Weather Tendency, Rainfall Measurement

drops to +76.8°F (24.9°C) or below and thereafter again increases to beyond +77°F (25°C), the data will be blinking, but no alarm will be activated. It has to drop to below +75.2°F (24°C) (with a pre-set hysteresis of 1.8°F (1°C)) so that the alarm can be produced again. Hysteresis values for the various weather data types are given in the following table:

Weather data	Hysteresis
Temperature	1.8°F (1°C)
Humidity	3% RH
Wind speed	3.1 mph

Note:

The temperature or humidity data will keep on flashing even after a key has been pressed to stop the alarm or buzzer has been switched off, to indicate that the current weather condition is out of the pre-set limit(s)

WEATHER FORECAST AND WEATHER TENDENCY

WEATHER FORECASTING ICONS:

Weather forecasting icons is displayed in any of the following combinations at the right bottom part of LCD:

TENDENCYTENDENCYTENDENCY

Sunny	Cloudy with sunny	Rainy
	intervals

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AIR PRESSURE HISTORY (ELECTRONIC BAROMETER WITH BAROMETRIC PRESSURE TREND)

The bottom section of the LCD also shows the relative air pressure value and the air pressure history.

Depending on programming conditions, display of the history of air pressure in form of a graph consisting of vertical bars.

The bar graph of the electronic barometer shows the air pressure history of the past 12 hours in five 3-hour steps.

Air pressure	Air pressure
changes in inHg	changes in hPa

The horizontal axis represents the last 12 hours air pressure recording (-12, -9, -6, -3 and 0 hour). The bars are plotted at each of the 5 steps and give the trend over the recorded period. The scale on the right compares the result. The "0" in the middle of this scale determines the current air pressure.

The vertical axis represents the air pressure changes in inHg (+0.12, +0.06, 0, -0.06, -

0.12.The “0” represents the current air pressure). The newly measured pressure was compared to the previously recorded pressure reading. The pressure change

is expressed by the difference between the current ("0h") and the past readings in division of ±2 hPa or ±0.06 inHg. If the bars are rising it indicates that the weather is getting better due to an increase in air pressure. If the bars go down it indicates a

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For every sudden or significant change in the air pressure, the weather icons will update accordingly to represent the change in weather.

(Every time a new average pressure value has been obtained (once per minute), this value is compared with an internal reference value. If the difference between these values is bigger than the selected weather tendency sensitivity, the weather-icon changes, either for worse or for better. In this case, the current pressure value becomes the new weather tendency reference.)

If the icons do not change, either the air pressure has not changed or the change has been too small for the Weather Center to register. So you may adjust the "sensitivity" of the pressure change checking in the setting mode –see WEATHER TENDENCY SENSITIVITY VALUE SETTING above.

However, if the icon displayed is a sun or raining cloud, there will be no change of icon if the weather gets any better (with sunny icon) or worse (with rainy icon) since the icons are already at their extremes.

The icons displayed forecasts the weather in terms of getting better or worse and not necessarily sunny or rainy as each icon indicates. For example, if the current weather is cloudy and the rainy icon is displayed, it does not mean that the product is faulty because it is not raining. It simply means that the air pressure has dropped and the weather is expected to get worse but not necessarily rainy.

Note:

After setting up, readings for weather forecasts should be disregarded for the next 12- 24 hours. This will allow sufficient time for the Weather station to collect air pressure data at a constant altitude and therefore result in a more accurate forecast.

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drop of the air pressure and the weather is expected to get worse from the present time "0".

At every full hour the current air pressure is used as a basis for the display of a new graph bar. The existing graph is then moved one column to the left.

Note:

For accurate barometric pressure trend, the Weather Center should operate at the same altitude. For example, it should not be moved. Should the unit be moved, for instance from the ground to the second floor of the house, the readings for the next 12-24 hours shall be discarded.

WIND DIRECTION AND WIND SPEED MEASUREMENT

In normal display mode, the second section of the LCD shows the following wind data.

•Wind direction (shown on the a compass scale of 16 divisions) and wind speed in Beaufort scale

•Wind chill in °F or °C

•Wind Speed in mph, km/h or m/s

			Text showing wind speed
			in Beaufort scale
			Pointer indicates the
			currently detected wind
			direction
				This alarm symbol
				indicates that the alarm
				is set On
Wind chill	Wind	speed

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Common to weather forecasting, absolute accuracy cannot be guaranteed. The weather forecasting feature is estimated to have an accuracy level of about 75% due to the varying areas the Weather Center has been designed for use. In areas that experience sudden changes in weather (for example from sunny to rain), the Weather Center will be more accurate compared to use in areas where the weather is stagnant most of the time (for example mostly sunny).

If the Weather Center is moved to another location significantly higher or lower than its initial standing point (for example from the ground floor to the upper floors of a house), discard the weather forecast for the next 48-60 hours, as the Weather Center may mistake the new location as being a possible change in air-pressure when really it is due to the slight change of altitude.

WEATHER TENDENCY INDICATOR

Working together with the weather icons is the weather tendency indicators (arrow located on the left and right sides of the weather icons). When the indicator points upwards, it means that the air-pressure is increasing and the weather is expected to improve, but when indicator points downwards, the air-pressure is dropping and the weather is expected to become worse.

Taking this into account, one can see how the weather has changed and is expected to change. For example, if the indicator is pointing downwards together with cloud and sun icons, then the last noticeable change in the weather was when it was sunny (the sun icon only). Therefore, the next change in the weather will be cloud with rain icons since the indicator is pointing downwards.

Note:

Once the weather tendency indicator has registered a change in air pressure, it will remain permanently visualized on the LCD.

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RAINFALL MEASUREMENT

The total rainfall measurement is displayed in the fourth section of the LCD, in the unit of mm or inch. (see VIEWING THE MIN/MAX WEATHER DATA below)

VIEWING THE HISTORY DATA

The Weather Center can store up to 200 sets of weather data which are recorded automatically at 3-hour intervals after the weather station is powered up, at the nearest time of 0:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00. For instance, if user has manually set the time as 14:52 after installing batteries, the first history record will be made at the coming 15:00 automatically. Then the second record will be on 18:00 and so on.

Each weather record includes the Wind direction, Wind speed in Beaufort scale, Wind chill temperature, wind speed, Outdoor temperature and humidity, relative pressure and total rainfall, pressure history and weather tendency. Also, the time and date of recording will be displayed.

Note:

In order to acquire the correct time of recording of the history records, you shall manually set the current time as soon as installing batteries to the Weather Center. Afterwards, you should avoid changing the pre-set time as it will also alter the recorded "time of recording" of each history record, which may lead to confusion.

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