Precipitation nowcasting ("rain starting in ~X min") #88

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opened 2026-07-18 05:31:47 +00:00 by claude-bot · 1 comment

claude-bot commented

2026-07-18 05:31:47 +00:00

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Short-range "minutely" precip prediction for a location — the single most-used feature of consumer weather apps and a natural fit for the per-location model. RainViewer (already wired as the radar fallback, radar.py) exposes nowcast frames, so there's a low-friction path to a first version; a richer version could ride a dedicated nowcast API. Could surface on the dashboard card and/or as an opt-in "precip incoming" notification. Missed because the forecast surface was scoped to NWS period/hourly forecasts, not sub-hourly nowcasting. Effort M, value Medium-High.

Filed from the 2026-07-17 codebase audit (docs/.internal/report-2026-07-17.md), finding I-18.

Short-range "minutely" precip prediction for a location — the single most-used feature of consumer weather apps and a natural fit for the per-location model. RainViewer (already wired as the radar fallback, `radar.py`) exposes nowcast frames, so there's a low-friction path to a first version; a richer version could ride a dedicated nowcast API. Could surface on the dashboard card and/or as an opt-in "precip incoming" notification. Missed because the forecast surface was scoped to NWS period/hourly forecasts, not sub-hourly nowcasting. Effort M, value Medium-High. --- _Filed from the 2026-07-17 codebase audit (`docs/.internal/report-2026-07-17.md`), finding I-18._

claude-bot added this to the v1.5.0 - Feature enhancements milestone

2026-07-18 05:31:47 +00:00

claude-bot added the

type:feature

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2026-07-18 05:31:47 +00:00

rbrooks referenced this issue from a commit

2026-07-19 16:00:12 +00:00

Add precipitation nowcast ("rain starting in ~X min") (#88)

claude-bot referenced this issue from a pull request that will close it,

2026-07-19 16:00:23 +00:00

v1.5.0 Phase 4: precipitation nowcast (#88) #115

claude-bot closed this issue

2026-07-19 16:07:44 +00:00

claude-bot referenced this issue from a commit

2026-07-19 16:07:44 +00:00

Merge pull request 'v1.5.0 Phase 4: precipitation nowcast (#88)' (#115) from feat/v1.5.0-phase4-radar-viz into main

claude-bot commented

2026-07-19 16:07:53 +00:00

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Done in #115 (merged). A short-range point precip nowcast per location using RainViewer's nowcast frames: services/nowcast.py samples the location's tile pixel (zoom 8) across the latest past frame + up to 7 future frames and derives "rain starting in ~X min" / "rain easing" / "no precip expected soon". Served at GET /api/locations/{id}/nowcast (auth + visibility, cached ~5 min, fully fail-soft → never raises), and shown as a lazy-loaded 💧 line on each dashboard location card (hidden on error/disabled — never blocks render). PRECIP_NOWCAST_ENABLED (default true). 16 tests; bulk 739 passed.

Documented caveats: RainViewer is a global mosaic (coarser than the authoritative NWS NEXRAD radar), single-pixel sampling is imprecise, and the horizon is short (~30 min) — it's a heads-up, not a forecast; NWS alerts remain the source of truth. A richer version on a dedicated nowcast API + an opt-in "precip incoming" notification remains a possible follow-up.

Done in #115 (merged). A short-range point precip nowcast per location using RainViewer's `nowcast` frames: `services/nowcast.py` samples the location's tile pixel (zoom 8) across the latest past frame + up to 7 future frames and derives "rain starting in ~X min" / "rain easing" / "no precip expected soon". Served at `GET /api/locations/{id}/nowcast` (auth + visibility, cached ~5 min, fully fail-soft → never raises), and shown as a lazy-loaded 💧 line on each dashboard location card (hidden on error/disabled — never blocks render). `PRECIP_NOWCAST_ENABLED` (default true). 16 tests; bulk 739 passed. Documented caveats: RainViewer is a global mosaic (coarser than the authoritative NWS NEXRAD radar), single-pixel sampling is imprecise, and the horizon is short (~30 min) — it's a heads-up, not a forecast; NWS alerts remain the source of truth. A richer version on a dedicated nowcast API + an opt-in "precip incoming" notification remains a possible follow-up.

claude-bot referenced this issue

2026-07-19 16:39:52 +00:00

Add v1.5.0 changelog #117

claude-bot referenced this issue

2026-08-01 01:25:59 +00:00

Precip nowcast says "no precip in the area" from one dry pixel while storms cover the tile; silently degrades when RainViewer has no nowcast frames #162