Slow cooling trend the next few days….Then back to the mid to upper 60s this weekend…..Changes still in the longer range next week…..
Wednesday October 8, 2014
Posted at 9:30 am by Howard
Today’s guidance continued to show the upper ridge over the far west weakening and at the same time….more instability aloft. Not enough to warrant putting showers in the forecast but a few sprinkles might not be all that surprising. Heights aloft are probably a bit higher than climo and so temps today will still be a bit above normal. At 500mb the circulation shows a very weak baggy trof within a long wave ridge. Temperatures will continue their slide to near climo by Friday. At the same time, Upper ridging will develop off shore and expand eastward into this weekend, allowing temperatures to recover a bit Saturday and Sunday as the 588DM iso-height visits California one last time?
As mentioned in past discussions….the tropical western pacific is quite active producing strong Typhoons now. Typhoon Phanfone last weekend hit Japan and hits energy is now wrapped up in a deep low over the West central pacific. A stronger Cat 5 typhoon VongFong is currently re-curving to the NW and continues to spin up with sustained winds of 165MPH and gusts near 200MPH predicted before the end of today. VongFong is the strongest Tropical storm in the world so far in 2014. Why do the Dweebs mention these tropical storms in it discussion’s? Because in October, there is a link between tropical storms in the western pacific, their phasing with the westerlies and west coast weather.
It appears that this time, the phasing effects of VongFong will bring cooler unsettled weather to the central west coast the second half of next week with even the chance of precipitation and below normal temperatures. I am using the support of the MJO which strongly protruds into phase I of the Wheeler-Hedon Phase Space.
See: Phase 1 Composites for Precip http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Precipitation/SON/combined_image.png
See Phase 1 Composites for Temperatures http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/SON/combined_image.png
Some interesting curiosities….
Looking at the SSTA’s over the mid latitudes there is a cold pool at about 175E with legs that is stretched back to the NW pacific and at the same time, the SSTA loop shows a tongue of cold water extending westward as well to about 150west. This may eventually lead to a strenghting of the positive PDO that has been weakening that past few months. See: http://bobtisdale.files.wordpress.com/2014/04/figure-13.png
There is a modest warm pool in the subtropics at about 170W that is really Juxtaposed to the cold pool. The warm pool will probably weaken over time.
For the record…..the last few months has shown the +PDO indices headed toward 0 and weakening.
Kelvin Wave action… There is plenty of it and so expect more warm subsurface water to be pushed east with it rising over time.
Dr Howard and the Dweebs………………………..:-)