This was pretty neat, this forecast map from yesterday’s 11 AM AST WRF-“GOOFUS” (GFS) run. Look at all the rain barging into Arizona and Catalina!
What’s remarkable is that the ensemble runs made yesterday’s prediction of rain, one discussed here, quite the “outlier” of the rest of the “members” of the spaghetti plots, so one wouldn’t be expecting to see any rain for Catalina again!
But, here was that rain again, and this whole storm complex along the California coast falling mostly within that time period where over the decades there has been a tendency for storms to strike the more southerly locations between the 10 and 20th of November, something that was mentioned yesterday as a bit of a conundrum. Rain, though not as much, was shown again in the next run based on 5 PM AST global data, and due to that prediction of less rain, I am not showing it.
Below is a comparison of how the ensemble outputs (shown as “spaghetti” plots of a couple of key contours at 500 mb (around 18,000 feet above sea level) have changed since yesterday. To this observer, its been an unusually large change in where the grouping of those key contours are in just 24 h (they always change some, of course).
Notice how the blue (contours of flow pretty much in the heart of the jet stream) and red lines (periphery of it) have been shifted 10 degrees latitude and more southward from the first plot to the second, latest spaghetti plot, indicating that we’re going to be more in the storm track at that time, and the likelihood of a rain threat on the 19th-20th is more credible, less subjectively based as was yesterday’s take. Maybe subjectivity in forecasting isn’t that bad afterall…
(unless I think of something later.)