long-range forecast<\/a>\u00a0for the upcoming winter season.<\/p>\nBased on current weather patterns, historical data and long-range modeling, Day believes it\u2019s going to be a longer, colder and snowier winter for Wyoming and the Rocky Mountain\u00a0region.<\/p>\n
\u201cFor this winter, overall, the whole state will be colder than last winter compared to the 30-year average,\u201d he said. \u201cThere should be more snow and cold this winter than last on both sides of the Continental Divide. I\u2019m sticking to that.\u201d<\/p>\n
So, does Day agree with Nunley and this two-week outlook? Not exactly, because it could be right for the wrong reasons.<\/p>\n
The Computer Said So<\/p>\n
Day\u2019s concern with Nunley\u2019s graphic is that it was produced by long-range weather modeling via computers.<\/p>\n
While an extremely potent tool for weather monitoring and forecasting, Day said\u00a0computer\u00a0modeling isn\u2019t the end-all, be-all and shouldn\u2019t be treated as such.<\/p>\n
\u201cYou see inconsistency with long-range modeling,\u201d he said. \u201cThe data is a tool, but when you post a graphic from a model verbatim, the possibility that it\u2019s going to change on the next model run is extremely high.\u201d<\/p>\n
Long-range modeling\u00a0uses current weather patterns to anticipate future fronts and systems and how they\u2019ll impact various regions. Day\u2019s concern is how much can change from day to day, let alone\u00a0over\u00a0two weeks.<\/p>\n
\u201cShowing a graphic from that particular run shows that it may snow the first week of September,\u201d he said. \u201cThree or four other model runs later, or even the next one, it may not show that.<\/p>\n
\u201cSo,\u00a0do you post the next model run that doesn’t show snow in September and say, \u2018Oh, just kidding?\u2019\u201d<\/p>\n
Day has cautioned against overreliance on long-range modeling for years, especially for Wyoming\u2019s forecasts. In his experience, Wyoming\u2019s weather is too erratic for confident forecasts two weeks out, let alone two months out.<\/p>\n
Extreme Prejudice<\/p>\n
Long-range forecasting puts Day in a difficult position. A modeling run that shows snow in the first week of September would support his long-range forecast for the upcoming winter, but he won\u2019t let it.<\/p>\n
\u201cThat graphic could end up being correct, but I don\u2019t have the confidence level to tell people right now, at this point in time, that it’s going to snow next week or that first week of September,\u201d he said. \u201cFrom what I\u2019m seeing, I can\u2019t say that.\u201d<\/p>\n
In Day\u2019s opinion, graphics like the one Nunley shared should be taken with \u201cextreme prejudice.\u201d<\/p>\n
The most reliable forecasts come from local sources, such as the National Weather Service offices in Riverton, Cheyenne and surrounding states that cover Wyoming.<\/p>\n
With a three-day weekend ahead, many Wyomingites are wondering whether to pack a swimsuit or a snowsuit for their outdoor excursions. Based on what he\u2019s seeing\u00a0Tuesday, Day felt confident enough to say snow will stay away for Labor Day.<\/p>\n
\u201cI don’t see it getting cold enough to snow in the mountains this Labor Day weekend,\u201d he said. \u201cOther than these afternoon showers and thunderstorms, especially on Saturday, I think it’s going to be a decent three-day weekend weather-wise.\u201d<\/p>\n
Day isn\u2019t ruling out snow during the first week of September, but two weeks is too far ahead for a forecast with strong confidence. Computers might say so, but he won\u2019t.<\/p>\n
\u201cWe kind of have to get the current pattern cleared out, see what evolves next as we go into sort of the next storm cycle, and see where things end up,\u201d he said. \u201cCould we get some high-country snowfall in early September? It’s certainly a possibility, but by no means is it a foregone conclusion.\u201d<\/p>\n
\u00a0<\/p>\n
Andrew Rossi can be reached at arossi@cowboystatedaily.com<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Snow in the first week of September? It\u2019s entirely possible, although some long-range forecasts can be misleading. Chris…\n","protected":false},"author":2,"featured_media":112411,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[191,74],"class_list":{"0":"post-112410","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-computing","8":"tag-computing","9":"tag-technology"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/112410","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=112410"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/112410\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/112411"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=112410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=112410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=112410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"A](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/08\/September-snow-map-Meteorologist-Chris-Nunley-8.26.25.jpg\")
A long-range computer forecast calling for snow in the first week of September, and possibly on Labor Day, can be misleading, meteorologist Don Day says. Those computer predictions \u201cdrive me nuts and gets people all ramped up,\u201d he says. \u201cI hate it.\u201d (Meteorologist Chris Nunley)Snowy Septembers<\/p>\n