Plaincast
What the forecast actually says — NWS Area Forecast Discussions, decoded into plain English.
Plaincast decodes the National Weather Service's Area Forecast Discussion — the real forecast, written 3 to 4 times a day by the meteorologist on shift — into plain English. The discussion is where a forecaster explains their reasoning: which models disagree, what they are watching, and how confident they are. Below is the current edition for Denver, with its shorthand expanded. The full experience — an AI plain-English summary beside the annotated original — loads with JavaScript, and every one of the 68 forecast offices has its own edition.
Cooler weather returns this weekend with chances for rain, mainly for the eastern plains.
Still a rather uncertain precipitation forecast for much of the I-25 corridor and mountains. but increasing chance for light rain/snow Saturday night and again Sunday night.
A cool start to next week, but a warming and drying trend likely by mid-week.
Another day closer to this weekend's storm system, and almost all of the details regarding precipitation potential remain unclear.
We'll start with what we know. A fairly strong surface cold front is still on track to arrive Saturday morning, sometime not too long after sunrise for most of the Denver metro. Unlike many of our cool season fronts, it will take some time to saturate the low levels, meaning that low/mid cloud cover will be slow to develop in the morning before stratus becomes more widespread during the afternoon hours. High temperatures Saturday afternoon may only rebound into the low 50s across most of the lower elevations.
Meanwhile, the main upper level low of interest is spinning over far southern California tonight, and should track off to the north and east during the day Saturday. Today's trends have been towards a slower (further west) and slightly stronger low. As a result, the deeper plume of moisture also ends up a touch further west. Most of tonight's CAMs throw a large precipitation shield from south to north during the afternoon and evening hours, with modest (~0.05-0.25") amounts as far west as the foothills and as far north as a Longmont - Greeley line. However, most of the global/regional deterministic guidance is not nearly as bullish with this potential, nor are most ensemble members during this time. It will be worth watching if either of these solutions fold with the 06/12z guidance later tonight. Of note - some of these wetter solutions also bring in favorable south-southeasterly flow into Park County where there could be a few inches of snow through Sunday AM.
By Sunday, forecast guidance really likes the idea of spinning up a well-defined Denver cyclone. As noted in the previous discussion, temperatures will probably warm up into the upper 50s to low 60s where clear skies develop, while many locations along the northern I-25 corridor and northeastern plains remain socked in stratus and see temperatures similar to Saturday. The upper low is expected to pivot across the region from Sunday afternoon into Monday morning. Again, one notable trend is to have this low be stronger/better defined, with a negatively tilted trough axis noted by Sunday night. As a result, the surface low over eastern Colorado ends up a bit more defined and low-level upslope is a touch stronger, while QG ascent is placed over our forecast area. Again, guidance is all over the place with the actual track of both the upper level and surface features. The the European model has been relatively consistent placing more substantial expected rainfall over our central/northern mountains into the adjacent plains, while many of this evening's CAMs kept most of the meaningful expected rainfall closer to the CO/WY border. Our preference here was closer the the blend-of-models forecast/the European model ensemble mean, though I would anticipate more changes to the forecast over the next 24-36 hours. At the very least, there's two well-defined periods for potential rain (and mountain snow) this weekend for those looking to see their favorite hydrometeors fall out of the sky.
Once the trough lifts to the north of our area Monday, we'll re- enter another period of dry weather through most of the week. Cool temperatures are still expected to stick around on Monday, with a warming trend by Tuesday under a broad warm air advection regime. Highs most days next week look to be somewhere in the 60s to near 70F.
Forecast confidence does decrease pretty quickly next week. Most models show a complex (or simply messy) pattern across most of the western CONUS. The dominant features will be a couple of strong shortwaves/closed lows across the Pacific Northwest and the northern Great Plains, with a couple weaker shortwaves associated with the subtropical jet. The general pattern supports warm and dry conditions, though there could be a couple periods of cooler/cloudier weather based on the track of those. There are signs that the subtropical jet becomes more active by next weekend. but it's difficult to translate that into an actual forecast at this time. We'll let this current weekend pass by before worrying too much about it.
This is the plain-text edition, decoded without AI so it loads anywhere. Read the whole Denver discussion at /o/BOU/, see what changed since the last one, or open The National Desk for where the weather is today.
Data from the National Weather Service. Translated by Claude. About · For developers & agents · Subscribe: RSS feed for this office · Source on GitHub