- -

"Rossy Waves...Above Chart"

"Rossy Waves...Above Chart" This chart depicts the "Rossby Waves" at the 500 mb level, 18,000 ft. which indicates
areas of high and low pressure. Gradient and Geostrophic Winds.

"Gradient Winds."

Gradient Winds...occur in areas where the winds are showing a curving pattern.

"Geostrophic Winds"

Geostrophic Winds...Are occurring where the contour pattern are on a straight course

Discovered in the late 1930's by: Carl G. Rossby: a Swidish-American Meteorologist for whom they are named.
Rossby Waves occur well above the friction level. They are steering currents and are at the 500 mb 18,000 feet level and higher.

Meteorology Charles A. Giannetta Meteorologist - Professor "Rossby Waves"

When the air flow is from West to East, it is said to be of "Zonal Flow" pattern,

The flow is Zonal the weather is generally more tranquil. When the air flow pattern is North/South, or South/North, the flow is
said to be Meridional. Merdional flow brings with it more aggressive weather. By observing the map, we can see that the
weather patter over the Souther United States from Arizona east to off the eastern coast of Florida is of a Zonal Flow. Looking over the
Northeastern US. we see low pressure over Eastern Canada. The wind flow over Ontario, Canada, Western New York and Western Pa. is of a
North South flow. Merdional Flow. More energetic weather.

At the top left of the chart, over the Indian Ocean we see what is called a (CUTOFF LOW or BLOCKING SYSTEM). This type of weather
pattern is cutoff from

The main East/West, North/South Flow, Rossby Waves. This weather pattern may persist for weeks or months at a time, showing no movement
and produce extremes in weather. Cold waves, heat waves, drought and excessive amounts of precipitation. This type
of weather pattern occurs many times over the United States. One pattern which most of us are familiar with is called: (The Bermuda High).

The Bermuda High can occur both in Summer and Winter. In Winter it produces cold and dry air over the Northeastern US. In Summertime it
can produce high temperatures and stagnant air over the Southern United States which many times causes droughts.