In the previous posting on the 15th (read it here) I discussed the transition period from the previous pattern to the new one. I discussed the "maybe" there would be a few opportunities for rainfall as the month ended. The "maybe" was because of this transition but if the same pattern was still dominating then that would boost confidence. That appears to be the case. Looking at this mornings upper air (jetstream) chart....
The red X over the Great Basin has been in place for a couple of days and is poised to to deepen into an upper low dropping south into New Mexico. But before that happens, a cold front will slide into the central plains and set up a zone of showers and thunderstorms. Gulf moisture was returning robustly (late September standards) and the interaction with upper level dynamics, the front and the surging moisture should bring widespread precipitation to the plains tonight (Wednesday) and tomorrow. A second round of more general rains will overspread the area as the aforementioned upper low lifts out into the central U.S., and the most likely time for that will be late Friday and Saturday. After that storm departs, it appears that it will be primarily dry for about a week.
Now, don't be misled. Not everyone will get a ton of rainfall through the weekend. The following map provided by the Weather Prediction Center gives an idea of where the heavier rain will be centered.
I think that almost everyone across the central and southern high plains will get at least 1/2 of an inch but there will likely will quite a few reports of 1 to 1 1/2 inches and a few locations over 3 inches.
Also in that previous posting, I had talked about the first cold snap during the first of the week of the 20th. That happened with low temperatures falling well into the 30s at many locations. I never saw a freezing report but a local event of freezing occurred it would have been very brief. Then later in the blog post I threw out the date of October 10 as a possible date of another cold snap but probably not a "killing" freeze. There is some support that date may be good.
Later into October - I'm not seeing much indication of a BIG cold blast. BUT - the new pattern is in the process of setting up and rapid changes can take place. More later....
I'll end this one with this graphic....
That zone between colder than normal and warmer than normal Pacific Ocean waters "MAY" be a big contributor in at least the fall and early winter cold shots. I'll try and address that in the next posting or two.