Chilly Northwest flow to continue through mid week before weak ridging warms Eastern CA over the weekend….It looks like another spectacular weekend for the high country with slightly above normal temps….Cooler breezy weather returns by the following midweek…Storm Clouds are on the Horizon…..
Tuesday October 4, 2016
Posted at 9:58 am by Howard
Strong blocking over the State of Alaska, WNW to Asia will be the dominant teleconnection effecting the weather along the central and especially the NW coast. An AR event is probably in the picture at some point as Low Pressure in the North Pacific and the Pacific Jet taps a lot of moisture aimed primarily at the Pacific Northwest by the middle of next week into the weekend of the 15th… We may get some showers this far south. The idea though is that it will be warm as we are on the Anti Cyclonic side of the big upper jet. It is great seeing a very strong jet like this in early October!
A large broad upper Trof remains over the intermountain west with only slow east ward progress expected. In the back of this trough is an a potent for October upper low that will bring Snow and rain to the pacific NW today. Another system is rapidly approaching the West Coast this morning in the fast NW flow; an impulse will move through the intermountain west bringing an increase of breeze and further cooling especially tomorrow Wednesday after a slight bump up in temps today. High temps at 8000 feet will likely remain in the 50s through Thursday. Note, the stronger upstream system is likely to bring stronger northwest breezes over Mono and Inyo county Wednesday/night. This is a dry pattern for the Mono County.
The Weekend will be dry and warmer with highs in the mid to upper 60s….Low temps in the 20s and 30s in Mammoth Lakes. I expect little wind over the weekend.
At the moment, a small splitting trof is likely to bring some increase in wind and cooling early next week. Dry weather is likely to prevail as 500mb heights rise over the west.
The current pattern of high latitude blocking is a major feature for the western hemisphere as this block over the Northern AK extend northwestward to Asia. This is suppressing the westerlies over the extratropical north pacific. It has begun the rainy season for the pacific NW and is bringing an end to their fire season. In the longer range, the block is forecasted to retrograde northwestward a bit and weaken west of the Dateline. . This change in the teleconnection should still keep a stronger trof over the north-east pacific. This is still a dry pattern for Central CA. The big question is, will there be amplification of the eastern pacific ridge currently near the dateline later next week? That would drive the westerlies south into Central CA. It is pretty early in the season for that. So the Dweebs will wait and watch!
Although it is likely that the block will fall apart eventually bringing Indian Summer to the Sierra, since these patterns often times repeat themselves, a similar block is possible later in the month or early next month. That would have major implication’s for snowfall and winter weather conditions for Mono County.
As another point, the Dweebs are becoming more comfortable with the notion that this winter will be quite different from the last 6, that have been below normal in precipitation. The Dweebs are more excited about the prospect’s for a better, wetter winter.
This is based upon the rapidly weakening +PDO, a +QBO that will should flip to negative by about year’s end and the warm water pool over the eastern pacific setting up farther west. “If these trends continue, the Dweebs feel that Mammoth will enjoy a very good water year. The next 60 days will really tell the story on these important features.
Note: Generally the view is that when the QBO is negative the atmosphere is more favorable for blocking patterns to occur in the jet stream over the Northern Pacific …Northern Canada …Arctic and Greenland areas. With more blocking patterns you get more snowstorms and more colder outbreaks. However, research does not support that directly.
Dr Howard and the Dweebs………………….:-)