The Strong off shore upper ridge has set up some strong upper troughing over CA and Western NV. Although Southern Mono Clounty should be spaired today from major rains….The upper forcing should shift south Thursday into Friday with better action for the Mammoth and June areas. Expect showers and Thunder with even the sierra crest getting some snowflakes during that time. There may be some areas that will get 1/2 inch of rain, especially Thursday afternoon into the night and Friday looks unsettled as well. By Friday night, a part of the trof shifts east and we get a break in the weather for the most part Saturday. Another chance to slight chance of showers returns Sunday and Monday. Temps will be in the 50s in Mammoth Thursday, Friday with low 60s returning over the weekend with 30s at night.  There is likely to be unsettled periods of WX during the month of June as well.


EL Nino From the CPC:

So far, the subsurface warming of ocean water below north of the Equator has been modest with some suggestion that a Modoki type El Nino may be in order as the Nino 3.4 area show modest warming.  The Modoki El Nino tends to provide most of the warming near the dateline and possibility the central american coast.  There is a strongwarm pool off the Central American Coast so this suggests the possibility of a Modoki event. Many Modoki El Ninos bring dryer winters to CA.

This discuession below suggests a stronger surge of sub surface warming is on the way this Summer, with the intensification of El Nino as it rises to the surface. The potential sub surface warmer surge would be due to a strong downwelling Kelvin Wave event.  If successful, this change would give better odds for a wetter winter than the typical Modoki event for California.


Last Updated – 05/23/23
Valid – 05/31/23 – 06/13/23
An active Madden-Julian Oscillation (MJO) signal remains apparent in various atmospheric fields, and continues to project well on the RMM-based and CPC upper-level velocity potential based MJO indices. Recent observations have indicated that other modes are interfering with this intraseasonal signal. Notably, the large circulation of Typhoon Mawar over the West Pacific, and persistent anomalously strong upper-level westerly winds over the East Pacific have caused a slowdown in the eastward propagation of the MJO, which had been on the fast end of the 30-60 day circumnavigational envelope throughout much of the Boreal Spring. The confluence of these modes has resulted in a very strong westerly wind burst (WWB) along the equatorial West Pacific, co-located with the warmest waters of the West Pacific warm pool. This WWB is likely to generate a strong and breaking downwelling oceanic Kelvin wave, which would serve to reinforce and increase the influx of warmer upper-ocean water across the equatorial Pacific. Therefore the MJO slowdown and tropical cyclone activity over the Pacific increases confidence in a transition towards El Nino conditions.