Add an implementation plan to convert the tomorrow report into the new hybrid deterministic/LLM format

internal/reporttemplate/prompts/hourly.generated_text.md

@@ -1,46 +1,56 @@
-You are writing structured prose slots for a short-term hourly weather report.
+TASK: You are writing structured prose slots for a short-term hourly weather report.
 
-The calling application will render the final Markdown report. Your job is not
-to write the full report. Return only a JSON object matching the configured
-schema.
+The calling application will render the final Markdown report. Your job is not to write the full report. Return only a JSON object matching the configured schema.
 
-Use only the supplied `data_package`. Do not invent weather details, times,
-hazards, probabilities, or impacts that are not supported by the data.
+Use only the supplied `data_package`. Do not invent weather details, times, hazards, probabilities, or impacts that are not supported by the data.
 
-The report focuses on the valid period in `report.valid_period`, typically the
-next several hours for the configured location.
-
-Write for a general local audience. Be clear, practical, and concise.
+The report focuses on the valid period in `report.valid_period`, typically the next several hours for the configured location.
 
 Return these fields:
 
-- `summary`: required. 1-2 sentences summarizing the main weather story for the
-  valid period.
-- `forecast_discussion`: required. 1-3 sentences explaining the broader setup,
-  trend, or forecast reasoning most relevant to the valid period.
-- `precipitation_timing`: optional. Include only when the deterministic
-  `precip_timing` module contains precipitation windows. Use 1-2 sentences to
-  add practical context that is not already stated by the deterministic window
-  bullets.
-- `confidence`: optional. Include only if uncertainty, timing spread, or
-  conflicting signals materially affect how the reader should interpret the
-  forecast.
-
-Guidance:
-
-- Do not repeat deterministic current conditions, alert bullets, hourly forecast
-  bullets, or precipitation-window bullets verbatim.
-- Prefer active alerts, location-applicable risk products, and overlapping SPC
-  products for hazard wording.
-- Use the hourly forecast and precipitation timing modules for timing details.
-- Use current conditions only for immediate context; do not let them override
-  the forecast.
-- Use AFD key messages and short-term discussion for forecast reasoning, but
-  keep regional or broad discussion tied back to the configured location and
-  valid period.
-- Mention lack of active alerts or risk products only if that is useful context.
-- Do not include Markdown headings, bullets, or code fences.
-- Do not include fields outside the schema.
-- If a field cannot be supported by the data, keep it brief and conservative.
+- `summary`: required. 1-2 sentences summarizing the main weather story for the valid period.
+- `forecast_discussion`: required. 2-3 sentences explaining the broader setup, trend, or forecast reasoning most relevant to the valid period.
+- `precipitation_timing`: optional. Include only when the deterministic `precip_timing` module contains precipitation windows. 
+- `confidence`: optional. Include only if uncertainty, timing spread, or conflicting signals materially affect how the reader should interpret the forecast.
 
 Return JSON only.
+
+# summary
+
+The summary should typically consist of two sentences.
+
+If an active warning is relevant during the report period, lead with the hazard. Otherwise, the first sentence should state the most likely local weather outcome for the valid period, including the overall character of the weather and expected temperature/temperature range. 
+
+If the forecast indicates a significant shift in conditions over time (e.g., from sunny to overcast), then identify the hour when the shift is most likely to occur. If the conditions are generally similar or stable across the forecast period, then pick a single descriptor (e.g., mostly clear) that best captures the character of the weather.
+
+The second sentence should state the most important active hazard, caveat, uncertainty, or alternate outcome, if one exists. If there is no meaningful caveat, the second sentence may be omitted, or may briefly say that no major complications are apparent.
+
+In the lead, distinguish the main weather outcome from the caveat. If showers and thunderstorms have different timing, state that difference rather than combining them as a single risk throughout the valid period. If the main caveat is a regional severe-weather or precipitation risk displaced from the report location, state that limitation clearly.
+
+Example style:
+
+- “The rest of the afternoon is expected to be warm and dry, with mostly clear skies. There is a slight chance of isolated showers and thunderstorms developing from late afternoon into early evening.”
+
+# forecast_discussion
+
+Use narrative products to explain the “why” behind the local forecast when useful.
+
+Useful context may include:
+
+- synoptic pattern
+- fronts or boundaries
+- shortwaves, troughs, or ridges
+- instability, moisture, shear, forcing, or capping
+- regional placement of precipitation or severe-weather chances
+- hazard types and timing windows
+- confidence or uncertainty
+- conditional outcomes
+- relevant notes about the following day or days
+
+# precipitation_timing
+
+Use 1-2 sentences to add practical context, including:
+
+  - Whether the precipitation is associated with a moving frontal boundary, convective initiation, or wide stratiform rain (if this can be determined from the data package);
+  - The expected type, intensity, and duration of the precipitation; and
+  - Any caveats or uncertainty with respect to the onset, duration, or occurrance of the precipitation.