Thursday 6:15 PM

Warming trend in play with lots of high clouds due to the splitting system off shore.  No real changes to the forecast other than to add some CU over the Sierra early in the weekend. There is a chance of snow showers Tuesday/Ngt.. No big deal though…The rest of next week looks fair.

At this point I do not see any major storminess in our future. Both 6 to 10 and 8 to 14 day outlooks are dry.  Beyond week 2 climate wise, it is getting pretty late in the season for a major storm….  The Dweebs will keep the faith for one or two more cold systems.  We have had decent snow producers in May historically, but they are not all that common, especially with all that anomalously warm Eastern Pacific Water. (+PDO)

 

The Dweeber……………………..:-)

 

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As the cold pool shifts east today and the clean up finishes up this afternoon, the Dweebs must remember that the QPF for our area in the sierra is often under estimated when;

1. You have the upper flow natural to the sierra.

2. A strong cold front with a lots of UVM ahead of it.

3. Good upper divergence over the area

4. Most of all….A cold pool capable of heavy convective showers following the front.  The heavy convective showers last night brought another .5 inches of H2O to the mountain and another 6 inches of snow. This was more than earlier forecasted by all forecasters early Tuesday AM for our area.  I will say that I did update between 2PM and 3 PM yesterday afternoon after looking at the latest RHHH “Rapid refresh model” when it was evident that heavy convective showers were headed for the Central Sierra during the night. We received 1 to 2 inch per hour snowfalls.

 

Forecast….

Partly cloudy during the afternoons the next few days with a warming trend into the weekend. Expect about 8 degree of warming over the next few days through Friday and then upper 50s over the weekend.

 

Longer range:

I personally like the next system better than some of the other Dweebs….    As although the models have the next system to be more of a northwest slider, to me it looks like it will have the potential to dig further west with time as the upper jet has a good temperature gradient as it digs south..  This is not to say that it is impossible for the current NW slider to continue into the shorter range. I am just beginning to see some bias more to the west.  Stay tuned….as this may end of being another decent April Snow Producer about Tuesday next week…..

 

El Nino:  It should be acknowledged that most climate scientist’s at this time are doing a great job of not hyping the developing El Nino over the EQ pacific. They were badly burned last year with the Modoki that set up leading to a winter similar to 1977.  This Dweeb does not want to hype it as well. However, there are some interesting observations that one should consider. There are some differences between where we are this year at this time as compared to last year at this time when it comes to the temps over the NINO basin.  Last year, there was a rather large Kelvin wave that surfaced over the eastern pacific. This year at this time we have the same scenario. IE Another very warm KV surfacing in the same area.  However, the big difference this year is that there are antecedent conditions that are much warmer already in the Nino Basin. The KV now surfacing will only add to that heat in the basin.  The average SSTA for the 3.4 region of all models is now “Forecasted to be 1.5C by *August.  That is within the moderate El Nino threshold. However, August is not December, January and February. A lot can happen 5 months later…. Nevertheless, the odds of reaching the moderate threshold temperature wise is very possible now by August.   Remember that for an El Nino to be classified as moderate,  it has to remain at about that threshold in the Nino 3.4 region for at least 3 months….

Some additional thoughts…

The record setting  MJO last month was able to move a lot of warm water eastward toward the EP.  The MJO space space shows it to reemerge out over the Indian Ocean. However, the signal may be related to low frequency noise due to either KV or RW action…  The Dweebs are questioning whether the MJO will strengthen enough to excite twin cyclones again, pushing more warm water eastward toward the eastern pacific later this month and into May…..thus bringing further warming to the Nino Basin.

The current KV now rising is amazing warm!

 

* http://www.bom.gov.au/climate/ahead/model-summary.shtml#tabs=Pacific-Ocean