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 Portland, 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 Portland (PQR) · issued Saturday, October 24 at 3:48 AM PDT.
Synopsis
Dry weather is expected through Saturday with overnight and early morning frost/freeze conditions across much of the region. Rain chances increase early Sunday morning as a broad upper level low moves over the region. An semi-active pattern continues through the middle of next week, with a brief period of dry conditions expected Tuesday with another round of light precipitation expected Wednesday. Beyond Wednesday, uncertainty increases as models ensembles diverge significantly from each other.
Discussion
Today through Friday. Transient upper-level ridging continues through this evening bringing clearing skies and light, offshore flow to the region. However, by tonight a broad upper level trough from the Gulf of Alaska will bring precipitation back into the forecast through at least early Monday morning. Current, high resolution ensemble guidance has rain beginning at the coast early Sunday morning and reaching inland locations through the afternoon, with the bulk of the precipitation expected to cease by Monday morning across the region. At this point, the chances for 0.25 inches of rain or more from 5 AM Sunday through 5 AM Tuesday are 80-90% along the coast and Coast Range, 70-80% along the I-5 corridor, and 60-70% in the Cascades and foothills. Even with the influx of precipitation into the region, seasonable conditions with milder overnight temperatures are expected to persist through at least the middle of next week. As the middle of next week approaches, forecast confidence decreases as the early week low pushes eastward, although long-range guidance does continue to support additional chances for rain, with 30-40% of ensemble members bringing another weather system to the Northeast Pacific Wednesday/Thursday, this system is not expected to be as impactful as the Sunday/Monday one. Overall, seasonable temperatures are favored to continue into the final week of October. As for those wondering what is expected for the final Saturday in October, ensemble guidance is pointing towards a drier solution with overnight lows above freezing. /42-36
This is the plain-text edition, decoded without AI so it loads anywhere. Read the whole Portland discussion at /o/PQR/, see what changed since the last one, or open The National Desk for where the weather is today.