8.2 KiB
Generate a Daily Weather Report from the following weatherreporter JSON data package.
The report may be for today or tomorrow. Determine the correct framing from report.variant, report.validPeriod, briefing.metadata.validPeriod, and briefing.daily.forecastSummaryDate.
Use Markdown.
CORE EDITORIAL GOAL
This is a personal weather-nerd briefing, not a generic public forecast. The report should answer:
- What is the most likely weather outcome for the day?
- What caveat, uncertainty, or alternate outcome matters relative to that most likely outcome?
- If precipitation is likely or meteorologically meaningful, when will it begin, when will it end, how intense will it be, how much is expected, and is severe weather expected?
- What should each daypart generally look and feel like?
- What broader meteorological setup or forecast dependency is worth watching?
SOURCE PRIORITY
Use the package in this order:
- Use
briefing.daily.bottomLinefor the overall daily theme, temperature range, and maximum precipitation probability. - Use
briefing.daily.daypartsfor daypart timing, temperatures, precipitation chances, wind, dominant conditions, and notable conditions. - Use
briefing.daily.narrativePeriodsto confirm and reconcile the official day/night forecast wording. - Use
briefing.daily.discussion.keyMessagesfor broader forecast context. - Use
briefing.daily.discussion.shortTermfor meteorological setup, local/regional nuance, confidence, uncertainty, and forecast dependencies that affect the report’s valid period. - Use
briefing.daily.discussion.longTermonly if it affects the valid day, the overnight period immediately following it, or a brief note about the following day/days. - Use
briefing.metadata.alertsand any alert details if present. - Use
recentChanges.itemsonly if it contains meaningful changes. - Use
sourceWarningsonly to avoid overclaiming. Do not mention missing internal sources unless they materially limit the report. - Use
currentConditionsonly as context at generation time. For tomorrow or future reports, do not describe current conditions as if they are forecast conditions.
LEAD REQUIREMENT
Begin the report with a two-sentence lead before any section headings.
The first sentence must state the most likely weather outcome for the day, including the overall character of the weather and the expected high temperature.
The second sentence must state the most important caveat, uncertainty, or alternate outcome, if one exists. If there is no meaningful caveat, the second sentence may briefly say that no major complications are apparent.
Examples of the desired style:
- “Saturday is expected to be warm, mostly cloudy, and mostly dry, with a high around 83.”
- “A few isolated showers or thunderstorms are possible during the afternoon and early evening, but coverage looks limited and most of the day should remain dry.”
Do not open with generic planning advice.
PRECIPITATION RULES
Do not overstate low precipitation probabilities.
Use precipitation wording consistently:
- 0–14%: usually omit unless relevant to a trend or caveat.
- 15–24%: “slight chance,” “isolated,” “spotty,” or “brief passing shower/storm possible.”
- 25–39%: “chance,” “scattered,” or “some showers/storms possible.”
- 40–59%: “good chance” or “showers/storms likely enough to plan around.”
- 60%+: “likely,” “wet,” or “unsettled,” if consistent with the narrative forecast.
Include a separate ## Precipitation Details section only when precipitation is likely, potentially impactful, or meteorologically interesting. In that section, address as many of the following as the data supports:
- likely start time
- likely end time
- most likely precipitation window
- expected intensity
- expected rainfall amount
- thunderstorm potential
- severe weather potential
- uncertainty in timing, coverage, or placement
If the package does not provide rainfall amounts, say nothing about totals unless the forecast discussion provides a supported qualitative signal. Do not invent QPF.
If precipitation chances are low and no meaningful impacts are expected, do not create a full precipitation section. Mention the caveat in the lead and relevant daypart bullets only.
DAYPART RULES
Include a ## Daypart Forecast section.
Write one concise bullet per available daypart. For generally dry or quiet dayparts, one short sentence is enough. Include the expected temperature range or trend and general conditions.
If precipitation is likely to begin, end, peak, or become more intense during a daypart, include more detail for that daypart.
Do not force equal detail across all dayparts.
AFD / METEOROLOGICAL CONTEXT RULES
Use the forecast discussion to explain the “why” behind the local forecast when it is relevant.
Useful AFD-derived content may include:
- synoptic pattern
- surface boundaries
- shortwaves/troughs/ridges
- instability, moisture, shear, or forcing
- regional placement of precipitation chances
- confidence or uncertainty
- conditional outcomes such as “if X occurs, Y becomes more likely”
- relevant notes about the following day or days
Do not quote or summarize the AFD at length. Translate it into concise plain English.
If AFD context describes hazards mainly outside the report location, preserve that limitation. Do not imply a direct local threat unless the hourly forecast, narrative forecast, alerts, or discussion clearly support it for the report location.
If briefing.daily.discussion.longTerm contains interesting context about the following day or larger pattern, you may include one short note in ## What to Watch, but do not let the long-term discussion dominate the Daily Report.
OUTPUT FORMAT
Use this structure:
[Today’s/Tomorrow’s] Weather — [Location Name]
[Valid date]
[Two-sentence lead.]
Daypart Forecast
- Morning: ...
- Midday: ...
- Afternoon: ...
- Evening: ...
- Overnight: ...
Only include dayparts present in the package. Use natural language timing where helpful.
Precipitation Details
Include ## Precipitation Details only if:
- precipitation probability reaches at least 30% during the valid period;
- thunder is mentioned and the timing/coverage is meteorologically interesting;
- the AFD discusses intensity, rainfall rates, flooding, severe potential, or meaningful uncertainty;
- recent changes materially affect precipitation timing, coverage, or intensity.
Recent Changes
Include this section only if recentChanges.items contains meaningful changes. Summarize the changes in plain English. Do not fabricate changes.
What to Watch
Include meteorological context, uncertainty, and conditional forecast factors. This is the right place to discuss the broader setup behind the forecast.
This section may include a short note about the following day or days if the forecast discussion supports something interesting or relevant.
In most cases, this section should include 2–4 sentences.
Sentence 1 should summarize the relevant local/regional meteorological setup. Sentence 2 should describe the main forecast uncertainty or conditional factor, if present. Sentence 3 should briefly mention the next day or broader pattern if the AFD supports it. Sentence 4 may be omitted unless there is a meaningful change, hazard, or longer-term pattern note.
Do not introduce mechanisms that are not stated or clearly implied by the forecast discussion. If the AFD does not identify the mechanism, describe the uncertainty more generally.
STYLE RULES
- Plainspoken, precise, and weather-literate.
- No generic public-safety filler.
- No umbrella/rain-jacket/snow-boots advice unless unusually warranted by the forecast.
- No commute or outdoor-plan boilerplate.
- No unsupported precision.
- No raw JSON, internal field names, source hashes, endpoint names, implementation details, or debugging notes.
- No apologies for missing data.
- Avoid phrases like “developing,” “moving in,” “clearing,” “threatening,” or “impacting” unless the timing and trend are clearly supported by the package.
- Prefer “most likely,” “possible,” “favored,” “conditional,” “limited coverage,” and “worth watching” when those phrases accurately reflect the data.