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 Sunday, August 23 at 3:55 PM MDT.
Messages
Monsoonal moisture continues this afternoon and evening but not as widely scattered as Saturday with localized flooding possible in the strongest storms.
Strong to severe storms possible (30-40%) looking more like the evening time frame after 6PM with a line of storms from Idaho capable of producing damaging winds up to 60 mph.
Monsoonal moisture will linger much of the week, with a chance of showers and thunderstorms each day. Temperatures will be closer to seasonable for this time of year nearing the end of August.
Update
Much more ample sunshine across the forecast area for the noon update as compared to yesterday. As such, temperatures will be a couple degree warmer this afternoon as Saturday afternoon as well. With better mixing, there will be a stronger breeze to go along with it as well gusting up to 25-30 mph at times outside of any storm activity and outflow winds. Nothing on radar currently but HiRes data is still pinpointing development by 2-3PM off leeside of the Absarokas and pushing in from the south off the Uintas for Sweetwater County. Much of this activity will be isolated in nature compared to yesterday's showers but expect lightning and a brief outflow over 40 mph with its eastward progression through the evening. With this, chance of rain have been adjusted and especially after the CRON wiped out the night shift's work to account for this heading into the evening hours.
This is where it will get a bit more interesting at least for Wyoming standards. A line of storm activity looks to form from southern Montana and across eastern Idaho by 6-7PM before pushing east into western Wyoming shortly there after along and ahead of the cold front. This will track through the forecast area by Monday morning. SPC continues with the Marginal Severe Risk, with an introduced Slight to the southwest portions of the state to include hatched wind. This looks to be overdone, even though damaging winds are possible up to 60 mph from the outflows ahead of the front. The instability with DCAPE values less than 500 J/kg just don't look to impressive as it nears radiational cooling towards sunset. There might be an hour or so before darkness, but the frontal passage will be later further south for the forecast area with its positive tilt and progressive eastward push. Stronger winds than that don't look great in the least but something to keep an eye on between 6-10PM west of the Divide. Beyond that as it makes its way to the east after midnight, the juice of the storms will be lost with mainly shower activity in its wake. The cold front will push the warmer moist air south and southeast.
Beyond that, status quo, as the monsoonal pattern continues but to a bit lesser extent. Temperatures behind this aforementioned cold front will bring afternoon highs closer to seasonable for this time of year ending the month of August with 80s east of the Divide even into next weekend.
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.