JACKSON, Wyo. – A quick-hitting system will bring rain and snow showers to the area on Thursday morning. Mild weather will return from Friday to Sunday, then a significant pattern change is on track for next week with winter-like temperatures and snow chances.
Recent Weather Conditions
Last Thursday, a 27-day dry streak was broken as a relatively minor storm system brought rain and snow to the area. Jackson received 0.35 inches of rain while ski resorts picked up 1-3 inches of snow.
While not a major storm, the cooler and wetter conditions were enough to significantly reduce fire behavior with the Pack Trail Fire.
This storm system also ended our balmy stretch of 70+ degree October weather. Last Thursday and Friday, high temperatures struggled to hit 50ºF in Jackson – nothing unusual, but much cooler compared to prior weeks.
Milder conditions have prevailed since Saturday with highs ranging from the upper 50s to mid 60s. But scattered clouds and gusty winds have kept it from feeling too warm in the afternoon, at least compared to prior weeks.
For the month as a whole, this has still been a very warm October with temperatures running 4.4ºF above average so far in Jackson. High temperatures have been well above normal this month, while low temperatures have been right around normal.
Quick Storm Thursday AM, then Drying Out This Weekend
A fast-moving disturbance will bring a round of showers to the area early on Thursday. A cold front will arrive at the leading edge with snow levels starting out at 8,000-9,000 feet initially before dawn, before dipping to 6,500-7,000 feet by the time precipitation ends by mid-morning Thursday.
Areas above 8,000 feet will pick up a quick 1-3 inches of snow (possibly higher at Targhee), with the potential for slushy pavement accumulations near the top of Teton Pass during the Thursday morning commute.
The towns of Jackson, Victor, and Driggs and other valley areas below 6,500 feet will see predominantly rain, with perhaps a few wet snowflakes mixed in toward the end. Rainfall amounts will be on the lighter side in the valleys, with most areas picking up less than a tenth of an inch.
Conditions will dry out on Thursday afternoon but temperatures will be cooler with highs in the upper 40s.
Dry and sunny conditions will prevail late this week and into the weekend. This may be the last weekend with good hiking conditions, so get out and enjoy while you can. Highs will reach the upper 50s on Friday and low to mid 60s on Saturday and Sunday, with winds picking up a bit on Sunday.
Much Colder Air Arrives Next Week, Along with Snow Chances
A significant pattern change will take place early next week as high pressure breaks down, allowing cold air to spill southward from Canada into our area. Two storm systems could also impact our area in the Monday (October 29) to Friday (November 2) timeframe.
The first storm is currently expected to arrive as early as Monday morning (exact timing subject to change this far out). The latest models are hinting that the strongest part of the storm may pass south of our area, but at the very least, the mountains could pick up some light snow, with a mix of rain and snow possible in the valleys.
Here is a 7-day snowfall projection, representing the average of 50 simulations of the European Model, through next Wednesday morning:
Another storm is projected during the middle to latter part of next week, right around Halloween. The Jackson Hole Valley may have a better chance of seeing its first snow accumulations of the season with colder air in place (if it doesn’t happen early in the week). But we’re still about a week away, so it’s only a “possibility” at this point.
Snow chances aside, next week could be our coldest stretch of weather since March. On Monday and Tuesday, highs are projected to reach the low 40s in the valleys, but from Wednesday to Friday, highs are only projected to reach the 30s.
Again, this is about a week away so the exact temperatures could change, but at the very least, below-average temperatures are likely. Average highs in Jackson at the end of October and the beginning of November are in the upper 40s, for perspective.
Here is NOAA’s 6-10 Temperature Outlook for October 29 to November 2:
In the mountains, temperatures will be winter-like next week with highs well below freezing, and snow that accumulates above 8,000 feet or so is likely not going anywhere until next spring/summer. In other words, whatever snow we receive next week will likely be setting the base for the season.
Alan Smith, Meteorologist
