Also, I discussed the change in the jet stream that would finally benefit California. The influences in the weather this past fall were NOT strictly from El Nino! But, recently the flow aloft has changed in that, at least temporarily, California would benefit in regards to precipitation. Looking at this mornings satellite image there are many disturbances in the flow aloft. But, at the same time, the flow has become rather disorganized and chaotic, in part due to the forcing from the north Pacific, but also from the equatorial warm waters across the Pacific (the "El Nino influences).
In the image above (click for a larger picture if you need to) the green lines with arrows represent the strongest flow aloft (the jet stream) and there were many splits to the flow. This makes the forecast for the central plains very complicated. The three primary systems, that could impact the plains, on this map are the X's with the superscripts 1, 2 and 3. X1 brought brief rain, sleet and a little snow to parts of Kansas, Missouri and now into the upper midwest. It wasn't much. X2 was moving out of the southwest U.S. and was bringing snow to mainly higher elevations of the southern Rockies. This may bring just a bit more precipitation to the central plains, but again, not much. X3 was probably the strongest of the disturbances and it should bring rain and snow to the center of the country by Friday or perhaps Saturday. You need to go to weather.gov to get details about this weather maker. I don't foresee it being a "huge" storm but probably big enough to bring 2 to 4 inches of snow to parts of Kansas (most likely from southeast Colorado into north central Kansas) - again go to the weather.gov website for details.
The flow aloft, by the time X3 gets going across the plains, should become dominated by a dip from the north into the midwest. On the satellite image above that would be where the cold air was building. Thus, expect a turn to sharply colder into at least Oklahoma and the northern parts of west Texas. There is some question on how far south the cold will get. This airmass should be capable of bringing single digit high temperatures as far south as northern Kansas by the weekend, or at least highs in the teens. One of the products I look at is a graph of something called the Arctic Oscillation. When the index drops sharply (and especially into the negative), cold air from the high latitudes is dislodged and typically drops well into the states. Here is the latest index and the outlook....
On average, below normal temperatures should be present across the central and northern plains (and midwest), lasting for 10 to 14 days but with a couple of brief warm-ups across the western high plains. It should be the coldest period that we've seen this winter. The southern high plains will get a taste of the cold too, but not near as cold as farther north.
There is a high amount of uncertainty of any possible storm development during the cold period. I have a hunch there might be one storm that intensifies as it drops south across the Rockies. The most likely time for this would be around January 17-18, but that is just a hunch and I don't feel really confident at this point. Computer models have no hint of this at all.
Towards the end of January there should be a big warm-up but also an increased opportunity of several storms. Keep checking back for those opportunities. I'll try and update again this Friday or Saturday.
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