From Jason:
"My question is with long range forecast (in terms of several weeks to months out) I seem to get a feeling almost like trying to tell the future. I relate this feeling almost to horoscope reading, which as a Christian I don't like or take part of. I have also heard in newsgroups lately that there is some type of Astroforcasting taking place.

How do you relate to this and feel in general about long-range forecast? Is a long-range forecast much like trying to tell the future, something the bible adheres us not to do?

Thank you for the working in the field you do and being a strong witness! If you are able a response would be greatly appreciated!"

Very interesting question.

Forecasts, especially short term, are based on well known fluid mechanic laws (since the air acts like a fluid and can be predicted using equations if you know its initial state). These forecasts are not based on anything "etherial." They are based purely on science and are designed to aid the everyday person in planning purposes.

Who wouldn't want to know when a major storm is coming? It would save lives. In addition, Jesus makes referece to forecasting in the Gospel of Matthew chapter 16:

1 ¶ The Pharisees and Sadducees came to Jesus and tested him by asking him to show them a sign from heaven.
2 He replied, "When evening comes, you say, `It will be fair weather, for the sky is red,'
3 and in the morning, `Today it will be stormy, for the sky is red and overcast.' You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times.

Forecasting is, in fact, a matter of interpreting the signs the Lord has given us.

Long-range forecasting is more speculative, but is still based on science. We use ocean water temperatures globally to try to determine long rainge trends. We cannot get specific about any single day beyond 7-8 days. This is called trendcasting.

In summary, I do not equate predicting one's future (strictly prohibited by God) with forecasting weather (based on science and designed to be helpful to the user, not to dictate a person's life choices).

From Kyle:
"What exactly does a forecast of 'fair' mean?"

A forecast of fair weather is usually one you will find given from the National Weather Service when no precipitation is forecast, but sky conditions may range anywhere from from clear to cloudy during the forecast period.

I tend to stay away from its use, personally, because it is often too nebulous to be useful as a forecast.

From Janice:
"What is the difference between a hurricane and a typhoon?"

None. It is a matter of symantics. If the system develops west of the international date line it is named a typhoon. If it is east of the dateline, it is a hurricane.

From The Duncans:
"Why do the leaves of a tree 'turn upside down' before a storm?"

There are three explanations that many times work in tandem. I list them in increasing importance.

First, the air in motion just ahead of a thunderstorm will frequently have an "updraft" component to it. As small as it is near the ground level, it can be enough to "turn" a leaf so that its underside shows or flutters.

Second, the breeze itself. Closer to the center of a high pressure system where there are no thunderstorms, winds are light. As a cold front approaches and the high pressure system moves east, the wind speeds pick up. The increasing wind speed alone will flutter the leaves so that the undersides flash to the observer from time to time.

Third, and probably most evident, as the thunderstorm is actually approaching from the west, the darker clouds serve as a contrast to both the tops and bottoms of leaves. This contrast allows the human eye to notice the leaves more even though it was visible before the dark clouds provided the backdrop.

Fron "jktan":
"Why do tornadoes happen most often in the spring?"

Tornadoes are most frequent when certain conditions are most available.... and they are:

Cold air stiull invading USA from Canada.
Warmer weather trying to move northward as the sun gets higher in the sky.
Dry air from the desert can move into the mid-levels of the atmosphere.

All these things come together most often in the spring with the best opportunity for everything to come together in the nation's breadbasket... what we call "tornado alley."

Fron Kathy Raines:
"What exactly is DEW POINT as opposed to RELATIVE HUMIDITY?"

 

Dew point is a direct measurement of how much water there is in
the air.... it is the air temperature at which the water in the
air would begin to condense (as dew, frost or fog).

It's biggest use is summertime comfort (May-Sept).

When the dew point is:

59 or lower.......COMFORTABLE
60-64.............SLIGHTLY HUMID
65-69.............MODERATELY HUMID
70+...............EXTREMELY HUMID

Unlike "relative humidity" which changes relative to the
temperature even when the amount of water in the air remains the
same, dew point is a direct measurement of water content of air.

Toss out relative humidity for comfort.

Use dew point!