# North Atlantic Storm Atlas — Maproom Brief

## Atlas subject
North Atlantic weather and shipping: a layered storm atlas tracking North Atlantic storms, pressure systems, and the major shipping lanes that cross them. The story hook is convoy and hazard routes — the tension between the sea lanes and the weather that makes them deadly.

## Layer set
1. **Base layer** — bathymetric-style ocean basemap (deep blues, subtle contour hints) with major landmasses (North America, Europe, Greenland, Iceland)
2. **Pressure layer** — isobar lines with labeled centres (H/L), colour-coded warm vs cold fronts
3. **Storm track layer** — historically-styled cyclone symbols, colour-coded by month/season, with draggable annotation pins for named storms
4. **Shipping lane layer** — principal North Atlantic shipping lanes (lanes, Traffic Separation Schemes), faded to near-transparent so they don't fight the storm layer
5. **Narrative overlay** — a guided-tour mode that walks through 5–7 historically significant storm events along the shipping routes, each with a dated annotation and short contextual note

## Navigation model
- Pan and zoom (mouse drag, scroll wheel, pinch on touch)
- Click a storm or pressure centre to open a side panel with detail: name, date, central pressure, max wave height if recorded, ships lost or affected
- Layer toggles in a floating control panel (top right)
- A minimap in the corner for orientation
- A "replay tour" button that steps through the narrative events in order, briefly highlighting each and displaying its annotation

## Visual direction
- Dark ocean basemap: deep navy `#0a1628` with subtle `#1a2d4a` depth tints
- Storm symbols: vivid amber `#f59e0b` for winter storms, electric blue `#3b82f6` for summer tropical remnants
- Fronts: warm `#ef4444` and cold `#60a5fa` line segments with appropriate markers
- Shipping lanes: translucent white `#ffffff33` lines with dashed overlays for TSS zones
- UI chrome: near-black `#111827` panels with `#e5e7eb` text and `#f59e0b` accent highlights
- Typography: `'IBM Plex Mono'` for data values, `'Inter'` for labels and UI

## Data sources (embedded, no live fetch)
- Synthetic storm track data for 8–10 named North Atlantic storms across a realistic date range
- Realistic pressure centre data with isobar paths
- Shipping lane coordinates approximating the principal North Atlantic routes: from Newfoundland to Liverpool, from Boston to Liverpool, the Azores bypass

## Technical constraints
- Single `index.html` file, all CSS/JS inline
- SVG-based map rendering (no external tile server)
- No external images; all visuals are SVG paths, CSS, and Canvas overlays
- Responsive: works on 375 px wide screens and up
- All interaction states reachable by keyboard
- LocalStorage for visited-storm memory and filter preferences