Weekly Weather Watch: Monday, December 11th, 2023
The stars at night are big and bright, deep in the heart of Texas….unless a significant precipitation event comes through, which will be the top of the headlines for this Weekly Weather Watch. Generally speaking, we continue to see moisture favor the Northwest and Eastern Seaboard, but a system will develop this week over the Southwest and Southern Plains to douse the area in heavy rain and some snow. For my monthly members, the discussion I showed with scenario two - the lower probability outcome - is becoming more likely with this system. This one has the “feelings” of El Niño…
Total precipitation this week is shown, and a zoomed-in image of the Southern Plains.
A widespread one to three-inch water event looks likely during the next few days. Those two images show total precipitation, meaning rain, snow, ice, or a mix. So, just in terms of snowfall, there is heavy, wet snow on the way to New Mexico into the Panhandles.
That’s nice and all, but we have things to do…So, when does it hit? Here’s an animation to show the progression of precipitation this week.
That animation shows the development of heavy showers mid-to-late week before the system combines with some tropical energy and moves along the Eastern Seaboard into next week. There is also occasional moisture to hit the Northwest, but not quite to the extent we have seen recently.
A shift occurs along the West Coast due to the atmospheric pattern over Russia, Asia, and the Pacific Ocean. A strong jetstream flow will begin to look more like what we see during El Niño events: a screaming jet from the tropical Pacific toward the West Coast and across the southern states. This will take some time to form fully, but it is looking likely and will impact us later this month into January. This fits with the “textbook” timing of El Niño impacts.
So, with that said, we are more likely than not tipping our scales toward the moisture aspects of El Niño as we close out 2023 and get into 2024. This week’s system over the South feels very El Niño to me, although attributing any one storm to a single climate-driver is foolish and I’ll criticize myself for doing so. In next week’s Weather Watch, we have a glimpse at Christmas Week and how this pattern shift, and more active jetstream, may impact us.
A potent Pacific storm is bringing a wet and wintry start to the week for the western U.S., with Southern California and the Southern Rockies facing the risk of flash flooding. Heavy snow is piling up in the Sierra Nevada and will shift to the Northern Rockies by Wednesday. As the week continues, the storm moves east, bringing widespread rain to the Plains, Mid-South, and eventually the East Coast. Meanwhile, another storm system is set to push into the Pacific Northwest by late weekend, keeping the unsettled weather going into next week. Tropical Storm Lorenzo remains out in the Atlantic with no expected U.S. impact. Across Canada, heavy western moisture, including snow in the mountains. Elsewhere, semi-heavy moisture will move across the central and eastern Prairies toward Ontario. Also, widespread frost and freezing temperatures are possible for all provinces.