For the Eastern Sierra, this pattern is still dry for the remaining time of this week, however, there will still be reasons to watch the skies over the next few nights.  The Gemini meteors will be flying tonight through Friday night with the peak of the meteor shower Wednesday night into early Thursday morning.  I guess if there is any consolation about this dry spell, it will be a spectacular night time display with up to 120 meteors per hour possible. This will be the best display of the year as the Summertime Presides meteor shower was hampered by a bright moon. The weather under the mega ridge will be cloudless. Calm winds and temperatures while still cold in the upper elevations, will be seasonably mild for this time of the year. This will make for very good viewing conditions. Constellation Gemini rises during the evening hours in the NE and is high in the sky at 2:00AM Thursday. Meteors will begin flying Wednesday mid-evening from the NE and then in all direction once Gemini is high in the sky at 2:00AM in all directions.  A small crescent moon will begin rising at 3:35AM.

 

The upper ridge remains in control……The Forecast still includes a warm up through Thursday and possibly Friday. Highs in the upper 50s Thursday and Friday with lows in the 20s to low 30s in the village.  WInds in town will be calm at least through Friday afternoon.

Here is the latest thinking from the Dweebs today Tuesday;

I listened in on the weekly discussion from the CPC.  The discussion mainly deals with tropical forcing which in many cases can be the tail that wags the dog.  The MJO is currently active, moving from phase 6 into Phase 7 and increasing in strength.  Phases 6-7 is the western pacific phase. When the MJO is strong in this area, it is usually associated with a strong +PNA pattern in the far west which we are now experiencing. The CPC prefers the ECMWF version of the RIMM (Phase Space) showing phase 7 to be the dominant mode for the next 5 to 7 days. Thereafter, the MJO progresses to phase 8 which moves the upper divergent and convective envelope out of the western pacific to near the dateline. This is almost always associated with retrogression of the long wave pattern for the west coast in the winter. IE the backward or westward redevelopment of the west coast ridge.  However, with the MJO forecasted to fall apart quickly as it moves through phase 8 toward phase space 1, (Possibly due to the anomalous cold waters of La Nina), most likely, we will not experience what would often take place thereafter. IE, the strong undercutting of the westerlies into the west coast. (That would be a wet pattern) An MJO strong through phase 8 usually results is an extension of the East Asian jet stream to the California coast. The CPC today indicated that this tropical convection is forecasted to be suppressed near the Dateline and in effect,  weakens the MJO…..”thus no gas to put the peddled to the metal”. (the latter are my words)

More comments……..

Most likely, we will be teased the next few weeks with some undercutting possibilities. Is undercutting of the westerlies possible? sure, but not probable.  The fact that only a few of the ensemble members shows that undercutting is testament to that possibility.

So, what is the more likely pattern that may emerge? As you all know, I am just a hobbyist. I love the science and all outcomes. Because I know that every outcome works out exactly the way it was supposed to…..Not necessary they way anyone forecasts it to!  😉

Here are my thoughts this evening….

  1. We are going a bit deeper into La Nina the next four weeks…..
  2. La Nina usually is usually highlighted by a -PNA pattern (long wave trof in the west) Occasional Arctic Outbreaks spilling westward.  (So far that has not happened)
  3. As far as weather pattern change, there is going to be retrogression…..No doubt about it!  The question is, how far west will it take place and how amplified will it be.  If a highly amplified pattern with a track down the west coast develops,, I am not all that concerned about any closed low diving so far south it misses California all together. Sea Surface temperatures anomalies have increased along the west coast and especially Southern CA due to the absence of storms this season. So the subtropical High (Hadley Cell) should be stronger further north.
  4. What the ECMWF ensembles are hinting about now is a system with “Arctic Air” plunging SW off the BC coast, spinning up then picking up some moisture from a weak undercutting. The issue is, the moisture tap is pretty much over by the time the front gets south of Northern CA. However, a cold storm for California around the 23rd of December, or any storm with Arctic Air in December is going to be a memorable cold system for Mammoth.
  5. The GFS ensembles actually has a similar pattern with the same cold Arctic Trof digging out of British Colombia. However, instead of the system coupling with moisture west and under a blocking high, this storm is just out right cold with limited moisture as the long wave sets up over the far west, more in line with what one would expect from a La Nina year.
  6. Remember, this is well over a week away and so there is plenty of time to watch and learn!
  7. The screaming message here is that we are going to get a transition and it looks cold for at least part of it.

 

Dr Howard and the Dweebs…………………………:-)