The "Jet Streams" Determine Our Weather Patterns
POSTED: Friday, December 13, 2013 - 10:58pm
UPDATED: Friday, December 13, 2013 - 11:02pm
Even The Borderland And The Desert Are Impacted By This Upper Level River Of Fast Moving Air
Thursday, December 12th, 2013 — Maybe you heard the term “jet stream” mentioned in weather forecasts.
This past Thursday the sub tropical jet stream brought in a weather disturbance and some moisture, both combined to produce widespread area rain showers and some snow to the north. The jet stream plays an important part in the formation of weather patterns and fronts.
What is this “jet stream”? The jet stream is a current of fast moving air found in the upper levels of the atmosphere. This rapid current is typically thousands of miles long, a few hundred miles wide, and only a few miles thick. Jet streams are usually found somewhere between 6 to 9 miles (10-15 km) above the earth's surface. The position of this upper-level jet stream indicates the location of the strongest surface temperature difference. Arctic and tropical air masses create a stronger difference temperature difference during our winter months, resulting in a strong jet stream. When summer comes around the surface temperature contrast is much less, so the jet stream winds are weaker. This river of air moves in an westerly to easterly direction.
The northern hemisphere jet stream is just the mix of warm air masses pushing north from the equator with cool/cold air masses that drop south from Canada and the North Pole. Thanks to this, we can determine and forecast the air pressure and temperature in every region of the planet.
The jet streams many times determine our dramatic temperature changes here in the Borderland. If the northern jet stream drops south over our area in the winter, this may allow a cold and deep enough air mass to push in over the mountains and quickly chill temperatures down some 10º to 20º+ in less than a day. High pressure will push the northern jet stream well to the north and allows our region to really warm or heat up.
The southern or sub tropical jet streams can also carry in humid air and this moisture turns into well needed rain in the desert.
So next time you are watching a television weather cast, (I suggest NewsChannel 9, KTSM, NBC, El Paso) watch for the greatest temperature differences and you will be in the vicinity of the upper level river of air that carries storm systems, the jet stream.
(Photo: Chuck DeBroder-KTSM)