What’s in a cloud?

2014-04-28 17:48:41.000 – Mike Dorfman,  Weather Observer

NULL

With an extensive collection of forecasting tools available online, forecasts today are vastly more accurate than they were even ten years ago. With the development of accurate models and weather stations scattered across the world, actually going outside to see what is happening seems to have become much less necessary in forecasting. It is still amazing how much you can learn by just looking outside.

Just by looking out your window and up at the sky, you can determine what time of year it is. In the summertime, clouds have a much more convective ‘puffy’ look that is caused from rising air as the sun heats up the ground. In the wintertime, clouds are often more stratiform and spread out as opposed to puffy and tall.

Noctilucent clouds are relatively uncommon clouds that occur extremely high in our atmosphere. They are only seen in the minutes after sunset, as they are extremely thin and are not visible through the roughly 45-55 miles of atmosphere below them. Recent research suggests that these clouds may be an indicator of weather and temperature thousands of miles away from their location.

More ordinary, but just-as-informative, lenticular and cirrostratus clouds can indicate short-term weather trends. Increasing lenticular clouds, which are lens-shaped stationary clouds and often form over mountains, can indicate possible precipitation in the near future. Cirrostratus clouds often spread out beyond an area of low pressure, and careful observation of these clouds can tell you whether a low pressure disturbance may move through the region. In addition, these clouds are often a precursor to a severe thunderstorm, pushing out over and ahead of the anvil of a thunderstorm.

In the summertime, thunderstorms are the largest threat to the summit. It is a bit harder to predict thunderstorms through observation, as they occur in a small area and often form and dissipate in a span of less than one day. However, keeping an eye on the vertical growth of clouds is extremely helpful in determining whether or not a cumulus cloud has the potential to grow into a thunderstorm. If a cloud is showing extensive vertical development, it is more likely to build into a thunderstorm.

Although forecasting through observation should never be used as a replacement for looking at a forecast, it is a useful aid when there is no forecast available. It is incredible how much you can learn about the weather by just looking up at the sky.

Mike Dorfman,  Weather Observer