Tuesday evening….

 

Closed upper lunker dropping south from the pacific NW into CA Wednesday night. Chilly pattern with some snowfall in the high country possible. .Showery with thunder as well. Chilly way to start the weekend….

 

Thursday PM:

Late spring like thunderstorm pattern.  Highs  in the upper 60s then cooling to the 50s by the 6th.

Deformation axis backing west to Mono County. Weak Upper Low off CA coast providing some weak Diffluence and Divergence over Sierra.  Local WSW Afternoon winds converging with southerly flow over Mono and Mineral counties spells afternoon and evening Thunder, mainly along highway 395 and eastern portions through Saturday. General weak troughing aloft and along w/stronger solar early May sun angle work with unstable air aloft generates more wide spread thunder Sunday through Tuesday including resort levels. Temps to remain above normal but cooler by mid-week. Although not a lot of confidence today in longer range…There might be some light snowfall around mid week from colder system from north.

The Dweebs will be taking some time off for a little R and R next week……

Next update the 12th….

 

PS:  There continues to be westerly wind bursts along equator over western pacific. This is likely associated with 2nd Kelvin Wave to the west of the Date Line.

Waters over Northern Australia now cooling…….  Press coming out from the area indicates record low temperatures near Darwin, Au. A possible sign of lower then normal SSTA’s to the North.

See:  http://www.weatherzone.com.au/news/record-april-low-temperatures-overnight-in-parts-of-northern-territory/285378

 

The Dweeber………………………:-)

 

Wednesday AM:

The Dweebs wanted to be clear about the term coupling as it pertains to the upcoming event/non event El Nino that is brewing out over the equatorial pacific. There are different kinds of coupling. Although the different kinds of coupling involve an air-sea relationship, the coupling is not always El Nino. It may be just Kelvin wave action warming the Nino Basin.   Here is an example.   You folks that ever tried to start an engine before fuel injection would either choke it, or spray Ether into the Carburetor.  The car would run for a while then die if the gas did not flow into the Carb afterwards.  So the KV could be looked at like the Ether that would get the engine to start. So if the water in this analogy was warm enough at the surface over the Nino Basin, there could be “Temporary” coupling in the usual areas like drier than normal conditions over NE South America or wetness over Texas,  East through the gulf states. This is not necessarily El Nino; just the usual teleconnections associated with the warm water over the Nino Basin associated with the KV.  Without the SOI being strongly Negative, (difference of surface air pressure between +Darwin and -Tahiti), there is likely to be no strong reversal of the trades to perpetuate and support the warm SSTA over the Nino, 3.4 to 1 region, through the Winter of 2016. Follow the SOI and ONI, They are the most significant indexes. Strong spikes into negative territory of the SOI in the -2 to -3 range causes the greatest chances of a wet California next winter. It needs to be strongly negative in mid to late Fall!  PS…According to the CPC, the SSTAs near the Dateline hit Historic Warm Levels this month!

SOI: https://www.ncdc.noaa.gov/teleconnections/enso/indicators/soi/

 

“ONI” DESCRIPTION: Warm (red) and cold (blue) periods based on a threshold of +/- 0.5oC for the Oceanic Niño Index (ONI) [3 month running mean of ERSST.v3b SST anomalies in the Niño 3.4 region (5oN-5oS, 120o-170oW)], based on centered 30-year base periods updated every 5 years.

ONI:  http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

 

Other interesting links: 

http://www.bom.gov.au/climate/current/soihtm1.shtml

http://www.bom.gov.au/climate/current/soi2.shtml

 

 

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Temperatures will remain well above normal this week as heights aloft remain above normal. At the same time, a weak trof will develop near the west coast increasing west winds, (Zephyr) during the afternoon and early evening hours Wednesday. It may be breezy again Thursday PM.

Lower heights develop over the weekend enough to destabilize the atmosphere and increase lapses rates. Over the higher elevated heat sources….isolated thunder will develop as early as Thursday PM areas mainly east of Mammoth with the areal coverage increasing each day through Monday as PWAT increases over Eastern CA. Temperatures will be the warmest the next few day reaching between 10 to 15 degrees above Climo then cool a bit with the afternoon clouds….

High temps this week will climb to the upper 60s in Mammoth beginning today.
Weekend outlook:

A 20% chance of thunderstorms Saturday PM  and Sunday PM increases to a 30% chance by Monday PM. Temps will be a little cooler but still remain above normal Monday because of the extra cloud cover by then….

Lows at night in the 30s this week…..

 

Longer Range:

It should be noted that we are under California Nino Condition’s Climatically which enhances springtime showers and Thunder over CA.  This is due to the exceptionally warm water off Baja and the CA coast. This is not El Nino, but the seasonal shift in the Spring months shifts the thermal Anchor from over the far eastern pacific inland allowing for wetter Spring conditions. Check out the post from two Scientist’s that work at the JAMSTEC and their report. http://www.jamstec.go.jp/e/about/press_release/20140425/

 

The Dweebs looked at the Global models this AM for next week. The GFS Ensembles shows a weak but full latitude trof coming through the west coast Tuesday/Wednesday 5th and 6th. Heights are low enough for a few showers…However, most likely clouds, cooling and wind Tuesday into Wednesday will result.  The ECMWF Ensemble’s are even less convincing as the 570 DM line is also near highway 80, there is a rather wide split in the flow as southern stream energy is diverted south down the coast into a subtropical trof that will spin up the subtropical jet over Baja next week.  The next opportunity of precipitation will not be until about the 2nd weekend of May or the 9th or 10th Mother’s Day weekend but that at this time is not all that exciting as there are significant differences between the two global models.

Always remember that model confidence is at biannual lows in both Spring and Fall.