Hemispheric Pattern To Remain Very Stable 4 Wave….No Significant Change This Week
Monday January 24, 2011
Posted at 9:10 am by Howard
The Western Hemispheric Weather Pattern will remain stable this week as a 4 wave stationary pattern is locked in. Key anchors are the deep Hudson Bay Low over east central Canada keeping the frigid WX over the Eastern CONUS and another deep stationary trough south of the Bering Sea. Teleconnections favor a continuation of strong west coast upper ridge for another week or two.
Even though this pattern will continue, the below normal precipitation pattern of the past will go through periods of weakness or slight retrogression to allow shots of cooling or even some light snow or snow showers. By the end of this week a system may move through the west coast ridge and provide some light snow or showers.
In the meantime, daytime highs in Mammoth will continues in the mid to upper 40s with lows in the teens and twenties. Winds will continue to be light in town and gusty over the sierra crest.
For the upcoming week….there will be a couple of weak short wave impulses that will be associated with some convergence aloft moving through the Rockies that will build surface pressures and thus increase the NE surface gradient Tuesday into Wednesday. So a period of East or Northeast wind will kick up over the Sierra Crest later Tuesday through Wednesday. Although this is a dry system, it will bring an increase of wind along with slight cooling for the Mammoth area by mid-week. Thereafter, the upper west coast ridge strengthens Thursday into Friday for warmer WX, then weakens Saturday into Monday as a short wave trof moves into California bringing the chance of some light snow or showers to the Mammoth Sunday/Monday along with cooler WX.
It is important to note that the possibility of some light snow for the Mammoth area the end of the week is not a pattern change. Rather just a weakness in the current ridge-trof set up hemispherically.
The next real change when ever it happens will be associated with a break down of the west coast ridge or retrogression of the same. A portion of the Hudson Bay Low will need to move far enough east for the wave length to become excessive, then amplification and retrogression of the west coast ridge to taking place. Timing wise…..this is not likely until sometime during the latter part of the first week of February. Additionally, The MJO is still very active and in the favorable teleconnecting area. (El Nino like) This may actually have been the stimulis in the creation of our current Ridge-Trof pattern as MJO does build a west coast ridge and favors the cold scenario in the east. (Very El Nino Like) Unfortunately for us, and which for whatever reason, the westerlies have not been strong enough without the necessary amplification for under cutting.
Mammoth Mountain continues to groom the excellent snow pack in the high country.
Dr Howard and the Dweebs…………………………………..:-)
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.