small bug fixes

src/routes/weather/options.ts

@@ -479,3 +479,37 @@ export const ensembleModels: WeatherModel[] = ensembleModelGroups.flatMap((group
 
 export const findEnsembleModel = (value: string): WeatherModel | undefined =>
 	ensembleModels.find((model) => model.value === value);
+
+/**
+ * A city inside each regional model's domain, used to offer a way out when the
+ * chosen model has no data for the current place. Keyed by the model-id prefix
+ * so new variants of a domain are covered without another entry.
+ */
+const IN_DOMAIN_CITY: [string, { slug: string; label: string }][] = [
+	['meteoswiss', { slug: 'zurich', label: 'Zürich' }],
+	['italia_meteo', { slug: 'rome', label: 'Rome' }],
+	['icon', { slug: 'berlin', label: 'Berlin' }],
+	['dwd', { slug: 'berlin', label: 'Berlin' }],
+	['meteofrance', { slug: 'paris', label: 'Paris' }],
+	['arpege', { slug: 'paris', label: 'Paris' }],
+	['arome', { slug: 'paris', label: 'Paris' }],
+	['ukmo', { slug: 'london', label: 'London' }],
+	['knmi', { slug: 'amsterdam', label: 'Amsterdam' }],
+	['dmi', { slug: 'copenhagen', label: 'Copenhagen' }],
+	['metno', { slug: 'oslo', label: 'Oslo' }],
+	['ncep', { slug: 'new-york', label: 'New York' }],
+	['gfs', { slug: 'new-york', label: 'New York' }],
+	['hrrr', { slug: 'new-york', label: 'New York' }],
+	['nbm', { slug: 'new-york', label: 'New York' }],
+	['gem', { slug: 'toronto', label: 'Toronto' }],
+	['jma', { slug: 'tokyo', label: 'Tokyo' }],
+	['kma', { slug: 'seoul', label: 'Seoul' }],
+	['cma', { slug: 'beijing', label: 'Beijing' }],
+	['bom', { slug: 'sydney', label: 'Sydney' }]
+];
+
+/** Where this model definitely has data, or null for a global model. */
+export function inDomainCity(model: string): { slug: string; label: string } | null {
+	const hit = IN_DOMAIN_CITY.find(([prefix]) => model.startsWith(prefix));
+	return hit ? hit[1] : null;
+}

src/routes/weather/week/[location]/+page.svelte

@@ -22,6 +22,8 @@
 
 	import { ChartContainer } from '$lib/components/charts';
 
+	import { href } from '$lib/i18n';
+	import * as m from '$lib/paraglide/messages';
 	import {
 		type FriendlyWeatherError,
 		type WeekForecastResult,
@@ -30,7 +32,7 @@
 	} from '$lib/services/weather';
 
 	import { useHeroActions } from '../../hero.svelte';
-	import { defaultParameters } from '../../options';
+	import { defaultParameters, inDomainCity } from '../../options';
 	import { computeDayNightWeatherCodes } from '../../utils/weather-codes';
 	import DailyStripSticky from './DailyStripSticky.svelte';
 	import DaySummary from './DaySummary.svelte';
@@ -114,6 +116,14 @@
 	// for the same place once their range is exhausted.
 	let locationRoute = $derived(buildLocationRoute(location));
 
+	// When a regional model has no data here, point at a place it does cover
+	// rather than only offering to abandon the model.
+	let suggestedCity = $derived.by(() => {
+		const city = inDomainCity(params.models?.[0] ?? '');
+		// pointless to offer the place we are already on
+		return city && city.slug !== locationRoute ? city : null;
+	});
+
 	let mounted = $state(false);
 	let loading = $state(true);
 	let loadError = $state<FriendlyWeatherError | null>(null);
@@ -157,6 +167,36 @@
 		return fd ? formatZoned(selectedDay, fd.timezone, 'yyyy-MM-dd') : '';
 	});
 
+	// A model swap can leave the open day outside what the new model covers (a
+	// short-range model after a 15-day one, say). Rather than showing an empty
+	// day, fall back to the nearest day that does have data - searching forward
+	// first, then back.
+	$effect(() => {
+		const fd = fetchedDaily;
+		if (!fd || wantedDay) return;
+		const days = fd.dailyDates;
+		if (days.length === 0) return;
+
+		const covered = (i: number) => {
+			const max = fd.daily.temperature_2m_max[i];
+			return max != null && Number.isFinite(max);
+		};
+		const current = days.findIndex(
+			(d) => formatZoned(d, fd.timezone, 'yyyy-MM-dd') === selectedDayKey
+		);
+		if (current >= 0 && covered(current)) return;
+
+		const from = current >= 0 ? current : 0;
+		for (let step = 0; step < days.length; step++) {
+			for (const i of [from + step, from - step]) {
+				if (i >= 0 && i < days.length && covered(i)) {
+					selectedDay.setTime(days[i].getTime());
+					return;
+				}
+			}
+		}
+	});
+
 	// Charts intentionally keep their current range: they show the full week
 	// unless the user narrows it via the range presets or Ctrl+scroll.
 	const switchDay = (date: Date) => {
@@ -324,12 +364,20 @@
 					>
 						Try again
 					</button>
+					{#if suggestedCity}
+						<a
+							class="cursor-pointer rounded-md border border-border bg-background px-3 py-1 text-xs font-semibold text-foreground transition-colors hover:bg-muted"
+							href={href('/weather/week/[location]', { location: suggestedCity.slug })}
+						>
+							{m.no_data_try_city({ city: suggestedCity.label })}
+						</a>
+					{/if}
 					{#if params.models?.[0] !== 'best_match'}
 						<button
 							class="cursor-pointer rounded-md border border-border bg-background px-3 py-1 text-xs font-semibold text-foreground transition-colors hover:bg-muted"
 							onclick={resetToBestMatch}
 						>
-							Switch to Best match
+							{m.no_data_best_match()}
 						</button>
 					{/if}
 				</div>
@@ -362,18 +410,27 @@
 					/>
 				</svg>
 				<div class="min-w-0 flex-1">
-					<p class="font-semibold">No forecast data for this model here</p>
+					<p class="font-semibold">{m.no_data_title()}</p>
 					<p class="text-[13px] opacity-90">
-						The selected weather model doesn't cover {location.name} — regional models only provide data
-						inside their own area.
+						{m.no_data_body({ location: location.name ?? '' })}
 					</p>
 				</div>
-				<button
-					class="cursor-pointer rounded-md border border-amber-500/50 bg-background/60 px-3 py-1 text-xs font-semibold transition-colors hover:bg-background"
-					onclick={resetToBestMatch}
-				>
-					Switch to Best match
-				</button>
+				<div class="flex flex-wrap items-center gap-2">
+					{#if suggestedCity}
+						<a
+							class="cursor-pointer rounded-md border border-amber-500/50 bg-background/60 px-3 py-1 text-xs font-semibold transition-colors hover:bg-background"
+							href={href('/weather/week/[location]', { location: suggestedCity.slug })}
+						>
+							{m.no_data_try_city({ city: suggestedCity.label })}
+						</a>
+					{/if}
+					<button
+						class="cursor-pointer rounded-md border border-amber-500/50 bg-background/60 px-3 py-1 text-xs font-semibold transition-colors hover:bg-background"
+						onclick={resetToBestMatch}
+					>
+						{m.no_data_best_match()}
+					</button>
+				</div>
 			</div>
 		{/if}