Thursday, July 2, 2009

June Re-Cap.....

Ok, so it's time for the re-cap on a very interesting month. Two things stood out in June, the cold & the wet.

Taking readings from the Truckee airport station June was 4.4 degrees below average, the coldest june in at least a decade. Taking an average of the temps in June, since 1999 June has averaged 1.04 degrees below average.

As far as precip there is a wide range in totals due to the spotty nature of downpours within the numerous thunderstorms in the month of June. The winner was Reno with 323% of normal at 1.52" of rainfall which put them 3rd all-time wettest June since records started in 1870. That was just shy of 1920 at 1.53" in the #2 spot. Just about all the reporting stations around the area were above average in rainfall. The Tahoe Basin was 120% of average overall which pushed them up to 79% of average so far on the water year. The Truckee River Basin was 184% of average overall which pushed them up to 89% of average on the water year.

That is three out of the last 4 months above average after a dry fall & start to winter. That makes sense since we started the shift towards our current weak el-nino in March, which may explain the moist flow that triggered thunderstorms in June. We will have to see what happens in July-Sept. The average precip for those months is low so it doesn't take much to go above average if we have some more unsettled weather. The weak El-Nino is forecast to hang around until the fall. Beyond that it could stay or we may begin to head back towards La Nina for next winter. We will have to monitor that into the fall. It would be easy for the El Nino to disappear with the rest of the Pacific being so cold, & once it's gone we may not see it again for a while. Hopefully it sticks around though, at least long enough to bring us a good fall & an early start to the season! BA

3 comments:

Frank said...

Hey, just wanted to drop by and say to say that I love your blog and have been following it closely since I discovered it last winter. In fact, it has been one of my inspirations to study the weather more, especially regarding long-term forecasting.

I have a question for you - you stated that though we are entering a slight el nino, there is a decent chance that we will go back into a la nina come fall. Looking at what the CPC has published recently, (http://www.cpc.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf, page 27 & 28 specifically) the CFS mean is shown peaking at +2 deg (a substantial el nino from what I have heard) at around NDJ (which would be awesome) and though a mathematical average is not shown for the other models, they look to be averaging at a little under +1 degree at OND-NDJ with only two models showing a dip below zero.

I know that weather has been proven unpredictable over a week out, but I'm assuming that is for something more along the lines of this location will get exactly 5.6 inches of snow in a period of 6 hours, etc. I am probably wrong though, so please correct me if I am. I am hoping that technology has improved enough that we can at least get an idea of what is going to happen :P

I'm hoping that the CPC and the models shown are credible enough that we can at least make generalized forecasts about what is going happen. Any thoughts on this? I know you have some :) Thanks, once again, for the wonderful blog that you run and I plan to continue following it for the winters to come.

BA said...

Hey Frank,

I have seen the CPC predictions, I take take them with a grain of salt. One of the sad things that has happened to weather in the past decade is that the research grants are only going to people who show data in favor of Global Warming. This to me has been evident in NOAA outlooks for a while now. They hardly ever show any below-avg. areas & make the warm areas warmer than they turn out to be. I try to keep a mix of privately funded meteorologists opinions & international because they aren't skewed by political agenda. I hope someday the weather is based on factual data & real science again instead of politics. I do think that we will have El Nino but not to the degree that those CPC charts show. There are several reasons El Nino could fall apart.

I have a professional subscription to Accuweather that is private & has really good forecasters that help in my forecasting. One free site with a ton of insight is Ed Berry's blog, "Atmospheric Insights" just google it. He is the one that I was reading that showed evidence of the breakdown of El Nino for next winter.

Long range forecasting will never be specific I think because the patterns never happen exactly the same. The longer we keep records though, & the more we pay attention to our own weather, the more we can predict what happens next based on what happened in the past.

BA said...

Current thinking is that the SOI being positive as well as the AAM heading towards the South could limit convection in the Pacific that would continue to blow up the warm water. It looks as if the models are overcorrecting as well for La Nina. Sadly, it looks as if El Nino may not hold on into the winter.