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 Riverton, 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.
Area Forecast Discussion · National Weather Service Riverton (RIW) · issued Friday, November 13 at 4:12 AM MST.
Messages
Dry and mild conditions persist across the Cowboy State today with breezy winds from Rock Springs to Casper and into Johnson County.
A weak disturbance will bring showers to portions of western and southern WY Saturday. Light accumulating snow may be possible for the higher elevations with overall impacts remaining minimal.
Mild and dry conditions return for Sunday into the start of next week.
There is the potential for a system to bring colder temperatures and widespread precipitation chances by the middle of next week.
Discussion
A fairly quiet day is forecast across the Cowboy State for Friday. Temperatures to no surprise remain mild with values 10 to 15 degrees above normal. Highs are expected to reach the upper 50s to low 60s east of the Divide and low to mid 50s for the west. Aside from mild temperatures, winds will increase in the afternoon ahead of an approaching disturbance. These winds will be mostly restricted to the Wind Corridor from Rock Springs to Casper and into Johnson County. Speeds are likely to range from 15 to 25 mph with gusts of 30 to 40 mph a few gusts up to 45 mph cannot be ruled out.
The aforementioned disturbance is in association with a trough that will begin to make its way onshore Friday afternoon. This disturbance continues to weaken and become more unorganized which will lead to lesser impacts for the area. Showers begin to move into western WY Saturday morning with much of the moisture staying across the higher elevations. That being said showers will be possible for the lower elevations of western WY throughout the day. Temperatures should be cold enough to support snow showers during the morning before warming temperatures transition any low elevation precipitation into rain. Some showers may be possible across southern WY as well but similar to other low elevation locations amounts will be minimal. East of the Divide will be quite similar to what has occurred over the past week or so. Mild temperatures and mostly dry conditions prevail as southwesterly flow will be unfavorable for showers. Due to the unorganized nature of the system much of the precipitation will end by Sunday. Overall, a coating to maybe an inch of snow is possible across the higher elevations of western WY. A very wet coating of snow cannot be ruled out for some low elevation locations Saturday morning but the warm temperatures should quickly melt any accumulation by the afternoon. Per usual locations east of the Divide will remain dry with mild temperatures. Breezy winds will be possible across the same locations as Friday.
The remainder of the weekend sees cooler but still above normal temperatures with mostly dry conditions. Above normal temperatures and dry conditions persist into the start of next week as ridging builds back in over the Inter Mountain West. Another disturbance is lurking around the corner for the middle of the week. Models show a trough digs across the western CONUS Monday before moving into the Great Basin by Tuesday. This disturbance makes its way over the area Tuesday into Wednesday and then quickly ejects into the Northern High Plains. The timing of this may be a little quick with models possibly slowing the trajectory by 12 to 24 hours as we get closer. At this time, the main things to watch will be the track and how well this system can organize. Models currently show it remaining mostly unorganized until it begins to leave the area where a more defined low begins to develop but by then it will be to the northeast of the area. If things stand, the greatest impacts look to be focused across western and northwestern WY. These locations would have the most favorable dynamics to see steady precipitation. As for other locations, there does look to be the possibility for some widespread precipitation but it would likely be on the lighter side. Temperatures may hinder any daytime snowfall mainly for locations east of the Divide. Overall, chances for accumulating snowfall will be the best across the higher and even lower elevations of western WY. Probabilistic guidance is currently showing a 30-50% chance for an inch or more of accumulating snow for the western valleys such as Star Valley and Jackson Hole. The higher elevation mountains of western WY have a 30-60% of 3 or more inches of snow. Other locations see much lower chances for any accumulating snowfall due to less favorable dynamics and warmer temperatures. However things are not set in stone and could possibly change as we head through the weekend, it definitely bears monitoring.
Colder more seasonable temperatures look to follow in behind this system as it moves out of the region for the second half of the week. Longer range models show another disturbance quickly move in for the end of the work week into the weekend. As mentioned in yesterdays discussion, this system is looking more potent. There looks to be greater potential for widespread precipitation possibly in the form of snow for mostly all elevations. Not to be a pessimist especially for those east of the Divide but with how things have gone the past winter, its best not to get overly excited for 200+ hour model depictions. So stay tuned as we wait and see what kind of trends may develop over the next few days.
This is the plain-text edition, decoded without AI so it loads anywhere. Read the whole Riverton discussion at /o/RIW/, see what changed since the last one, or open The National Desk for where the weather is today.