Well its the middle of May and the Dweebs are always thinking about weather and climate. Although, snow in the month of May is not unusual here in Mammoth, and in fact happens in most years, the persistence of cooler then normal temps is. Just look at the snow pack for this time of the year. It is still at least 150% of normal. The roads in the lakes basin and down to Reds meadow is probably with still 7 to 10 feet over the top and it is likely that the road over Tioga will not open until well into June.  There are the reports of 75 foot snowpacks covering roads in the mountain areas of the pacific northwest.  Must be Global Warming?  😉

Blame it on the negative PDO and a very slow awaking Sun from a long hibernation.

The negitive phase of the pacific decadial oscillation (PDO) is going strong and if history repeats itself may continue more on then off for the next 20 to 30 years. That means that the SSTs over the eastern pacific are colder then normal and that the west should have more precipitation and colder WX in the years to come. Summer may tend to be cooler and winters earlier and longer. El Ninos will tend to be weaker or shorter lived. If you want to get an idea of the weather for a negative PDO just study the weather of the 1930s, 40s and 50s here in this country. Watch La Nina this year. It is currently weakening and should pretty much be gone by Summer. However, watch and see if it does not return this Fall!

Current Discussion:

Active pattern to continue through Wednesday.  A Cold/wet upper low with a 130knot upper jet will cut through Central Ca  through tomorrow.

The position of the upper jet is west northwest and the axis just south of Mammoth. Good for divergence aloft in the front left quad over Mammoth.  Although the second impulse fizzled last night, the next one or the 3rd in the series will bring heavy snowfall after midnight tonight into Wednesday morning, with several inches accumulation on our local roads, especially above 8000 feet. Over a foot of new is possible over the crest by Wed PM.

Unstable air aloft with warming surfaces will allow a few afternoon convective showers to develop each afternoon Thursday and Friday…then a new negative trof digs in Saturday with more unsettled weather through Monday. 

When will it end?  When will warm weather return to the high country for an extended visit?

It is the Dweebs opinion that track of MJO will play an important part in the pattern across the Pacific and the west coast. The problem is that the forecast from NCEP is for the MJO to circle back from its current position in Phase 8 into phase 7 during the last week of May. However, the ECMWF does not agree as it progresses MJO through phase 8 as it weekens it rapidly.  Hopfully by the end of this week they will become more in agreement.  For whatever it is worth the 8 to 14 days outlooks do build a ridge into California by the end of the month. However, this possibility is probably unlikely, as based upon persistence, and the NCEP MJO model, the Dweebs feel that the storm machine will probably keep right on cranking into June.

The Dweeber………………….:-)

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.