Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/customer/www/docweather.com/public_html/global_functions.php on line 357

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/customer/www/docweather.com/public_html/global_functions.php on line 357

Winter 2006: jet stream patterns. - 02.09.06

In the winter of 2006 the disturbance diamond has straddled the West Coast in February.

---

Fig.1

To gain insight into the unusual path of the jet stream this winter, it is useful to look at the different patterns that can emerge around the disturbance diamond (see figure 9) in a given year in order to understand the way that the polar jet stream is influenced by this important feature of the eclipse grid. In the fig 1 we can see the situation where the easternmost 45° jet curve of the eastern pair of eclipse points is influenced by to high-pressure values (blue). In this configuration, a block will often form over the Maritimes. This type of placement enables the polar jet stream to drop into the Ohio Valley bringing strong cold and storms to this area. Farther west the 72° jet curve is also part of this high-pressure value supporting a blocking pattern over the Rockies. This pattern often results in the jet stream across the Pacific being pushed up into BC. From there it descends into the continent often bringing cold and turbulent weather.

Fig.2

In the second image we can see that all of the jet curves from the eastern set of points are aspected to high-pressure. This pattern forces the trans-continental polar jet to the north since the highs are placed much closer together. In this pattern the polar jet often moves into a zonal configuration and radically shifts the temperatures in the continent to much warmer levels. Farther west the 72° jet curve mirrors this placement with the result that the flow from the storm gate in the PNW is opened. This is due to the fact that the blocking influence is out over the ocean off of the West Coast in the center of the Gulf of Alaska. This type of placement results in a zonal flow pattern bringing moderate temperatures to the continent (red arrow). Other influences for the zonal flow in January can be found by clicking on the link.

ANALOG YEAR 1996 . During this year there was an 11 week wet spell for PNW in the fall. This is a major pattern for the northwest when the disturbance diamond is over the West Coast and the eclipse points are transited by a slow moving outer planet. There is also the enhanced possibility of a split jet stream over the E Pacific when the disturbance diamond is over the West Coast. Although for the split jet to occur the Sea Surface Temperatures at the equator over the eastern Pacific need to be very warm in order to draw the jet to the south. All indications this year point to a continuation of the present cooling trend at the equator that is the signal for a weak La Nina. As a result the zonal flow this January has dominated the continent. The high-pressure values on the eastern pair of eclipse points were generated by aspects from the lunar node for most of the month of January. This pattern put high pressure over both coasts resulting in a jet stream that was much higher to the north than usual. This was also a pattern for the winter of 1996.

All contents of this site, unless otherwise noted, are © 2004-2023 Dennis Klocek. All Rights Reserved.