It's the day before the 4th of July as I sit here and another thunderstorm moves through. We had a couple of dry weeks but the moisture is back with afternoon thunderstorms firing daily. Here is a pic I posted to the Tahoe Weather Instagram page which you can go to by clicking the pic.
We had a dry lightning strike fire in June down in Markleeville and then a couple of days ago a flash flood warning over the same area as a thunderstorm dropped heavy rain. Ironic... The month of June for the Tahoe Basin brought 134% of average rainfall, and 113% for the Truckee River Basin. The 3rd above average precip month in a row, except that doesn't say much since we don't receive much precip normally in these months. For the water year we are only up to 62% of average for the Tahoe Basin.
It was another warm month with temperatures a few degrees above average. The rain should only last through the 4th and then we dry out, but the heat should continue much of the Summer.
In the last post I updated on El Nino with caution on how strong it will stay into Winter. Another month has gone by and the waters continue to warm. The current update as of Monday from the CPC had 3 of the 4 ENSO regions into Strong territory.
You can see that the big difference since last Winter isn't just warmer water temps, but much warmer in region 1+2. That is a change from a central Pacific centered El Nino to a more classic extension to the West Coast of South America.
That image is the current Sea Surface temperature departures, but the one difference compared to the last big El Nino in 97-98 is glaring. Currently we still have a big warm blob of water off the CA coast that we blamed for the ridge and dry weather the past 2 seasons. Look at October 97 with the cold water off the coast.
In speaking with our new climatologist at Opensnow Dr. Amato Evan, who will be helping with our seasonal forecasts, the impacts of the warm water off the coast in conjunction with El Nino are not certain. The last 2 strong El Ninos had the warm water non-existent or further South.
That adds to my apprehensions about the El Nino from the last post, that it is still too early to know if it will stay strong through the 15-16 Winter. The CPC has upped the chances of El Nino conditions through the Winter to 85%, but that is not for a strong El Nino just any El Nino. The forecast models have predicted El Nino the last 2 Summers and it didn't happen. The difference this Summer is that we already have strong conditions.
What is also positive is the amount of Westerly wind bursts continuing with the tropical activity in the Western Pacific and MJO activity moving through the Pacific. The water should continue to warm for now increasing the chances that we will see strong El Nino conditions at least into the Fall. That could mean an active pattern for the Fall with some early snow.
As mentioned in the last post and over the last several years, a weak or moderate El Nino historically brings equal chances for below average snowfall during the Winter as above average. Chances increase with Strong El Nino. Still a little early to believe for sure the strong conditions will hold into the Winter. Even the model above shows conditions weakening when Winter starts. The warm water can cause the winds that caused it to weaken and ultimately an El Nino will eventually reverse, and it can happen fairly quickly. And then add in that we do not for sure know how the warm water off the coast will factor in.
Still, it is nice to dream as we look at the latest CFS precip forecast for CA next Winter!
So we are hoping for a Strong El Nino that historically can bring big rains to CA. But cautiously optimistic for next Winter. At least it will be different than the conditions we had the last 4 Winters and it can't get much worse so a change is good. In the spirit of the recent trend of posting flags over our profile pics to support our causes, I decided to post the El Nino flag over the Tahoe Weather FB profile pic in support of a Strong El Nino this Winter.
I hope everyone has a happy and safe 4th of July weekend. Please don't leave your trash on our beaches.