Weather Briefing — Med Trip

Snapshot: Tue 18 Aug 2026 16:57Z • Area: 34–45°N, 6°W–36°E

> ⚠️ Note: voyage brief says "April 2026" but the charts are dated 18 Aug 2026. Briefing is written to the charts on the table. Please confirm intended dates.

Current synoptic setup

The Mediterranean is under benign, summer-pattern control. Chart 1 shows the Azores High ridging strongly into Iberia and the western Med with a 1025 hPa centre near 40°N 25°W and a 1020 hPa ridge axis running east across the Balearics into the Tyrrhenian. A weak 1015 hPa trough sags across the central Med (Adriatic/Ionian) with no closed low. The Atlantic storm track is well north — a 1000 hPa low south of Iceland and a 1005 hPa low off Norway — both far from the route. 500 hPa heights over the basin are 576–584 dam with no sharp shortwave. Chart 4 confirms light winds (mostly 6–14 kt) across the whole basin, with only local acceleration zones in the Gulf of Lion and Aegean.

72-hour outlook

Day 1 (Tue→Wed): Ridge holds. W/NW 8–14 kt western Med, NW 10–15 kt Gulf of Lion (local mistral touch, gusts to 20), NE 12–18 kt in the Aegean (etesian). Seas 0.8–1.5 m, Aegean 1.5–2.0 m. No fronts.

Day 2 (Wed→Thu) — Chart 2 (t+48): Azores ridge shifts slightly east; 1025 hPa centre now 42°N 15°W, ridge axis over Sardinia. Winds ease further in the western basin (W 6–12 kt), central Med light and variable 5–10 kt, Aegean etesian steady NE 15–20 kt. Seas 0.5–1.2 m west, 1.5–2.2 m Aegean.

Day 3 (Thu→Fri) — Chart 3 (t+96): A deepening 1000 hPa low tracks to ~55°N 30°W (well north of route) but its ridge amplifies over Iberia (1030 hPa noted west of Portugal). Med surface pressure 1015–1020 — still quiet. Expect W 10–15 kt western basin, Gulf of Lion freshening to NW 15–22 kt as the ridge steepens, Aegean NE 18–22 kt. Seas 1.0–1.8 m west, 2.0–2.5 m Aegean.

Top 3 risks to watch

• Mistral spin-up in Gulf of Lion. Chart 3 shows tightening isobar spacing between the Iberian ridge and Alpine trough by Day 3. Magnitude uncertain — GFS often under-forecasts channelled mistral by 5–10 kt. Trigger: Marseille/Cap Béar METAR gusts >25 kt or Perpignan pressure rising >1020 hPa faster than forecast — delay a Lion crossing.

• Aegean etesian persistence/strength. Chart 4 already shows 15–20 kt streaks; the Balkan thermal trough on Charts 2–3 will reinforce. Uncertain how far south it bites (Cyclades vs. Crete channel). Trigger: Mykonos/Naxos observed >25 kt sustained — route south of Crete or wait in lee.

• Atlantic low pushing troughs into western Med late. Chart 3 hints at height falls approaching Iberia beyond t+96. Timing uncertain — could accelerate or stall. Trigger: Azores 500 hPa heights falling below 572 dam, or a surface low <1005 hPa west of 15°W — reassess Balearic/Alborán legs.

Routing considerations

Window is open — depart now. Next 72 hours are as benign as summer Med gets in the western basin. Prioritise westward or Balearic legs early (Days 1–2) before the Day 3 mistral signal materialises; if crossing the Gulf of Lion, aim to clear Cap Creus by Wed 12Z. Central Med (Tyrrhenian, Ionian) is a light-air motor-sail all three days — carry fuel. For any Aegean leg, favour the southern/western semicircle of the etesian flow (lee of Crete, Peloponnese) rather than the exposed Cyclades chutes. Refresh GFS + OPC Atlantic surface analysis every 12 h; the Day 3+ picture depends on how far south that North Atlantic low's trough digs.

Advisory only — verify against your own obs and the next model cycle before committing to each leg.

Weather Briefing — Med Trip

Issued: Mon 17 Aug 2026 17:00 UTC · Valid through Wed 19 Aug 00Z

Area: 34–45°N, 6°W–36°E

---

Current synoptic setup

The Mediterranean basin is under broad high pressure, with a 1015–1020 hPa ridge extending from the Azores High (centred ~1025 hPa west of Iberia, Chart 1) across the western Med and North Africa. 500 mb heights over the basin are 576–584 gpdm — a warm, stable upper ridge with weak flow. The only active feature nearby is a 1000 hPa low over the northern North Sea / southern Norway (Chart 1) with a trailing frontal system draped across the British Isles; this stays well north of the route. Chart 3 shows the Med generally light: <10 kt across most of the basin, with the usual local accelerations — a Mistral/Ligurian NW'ly at 14–20 kt in the Gulf of Lion, and 12–18 kt Etesian N'lies in the Aegean. Ionian, Tyrrhenian and Balearic waters are near-calm to 8 kt.

72-hour outlook

Day 1 (Mon 17 / Tue 18): Western basin (Balearics, Sardinia): NW 8–14 kt, easing overnight. Gulf of Lion NW 15–20 kt, gusts 25 near the Rhône. Central Med: variable <8 kt. Aegean N/NE 12–18 kt (typical meltemi). Seas 0.5–1.0 m generally; 1.5–2.0 m in the Mistral fetch. No fronts reach the route.

Day 2 (Tue 18): Ridge holds (Chart 2 shows 1020 hPa still anchored over Iberia/W Med). Winds ease further in the west — Balearic/Tyrrhenian light and variable <6 kt, motoring conditions. Mistral relaxes to 10–15 kt. Aegean steady N 15–18 kt. Seas <1 m outside the Aegean.

Day 3 (Wed 19, Chart 4): A shortwave trough drops SE across the UK/North Sea with the 1000 hPa low deepening slightly over Scandinavia, but the Med ridge is undisturbed. Expect continuation: light W'ly-variable across the basin, Mistral 12–18 kt, Aegean N 15–20 kt. No frontal passage on the route through 72 h.

Top 3 risks to watch

• Mistral reinforcement in the Gulf of Lion. Chart 4 hints at a tightening pressure gradient between the Scandinavian low and the Iberian high by Day 3. Change plan if: Marseille/Cap Béar METAR shows sustained >25 kt or 1017 hPa isobar sags south of 44°N.
• Meltemi surge in the Aegean. Charts 3–4 already show a persistent N'ly 15–20 kt tongue; deep Scandinavian low could push this to 25–30 kt. Change plan if: Lemnos/Mykonos stations report gusts >28 kt or thermal low over Anatolia deepens below 1005 hPa.
• Thermal thunderstorms over central-Med islands. Chart 5 (E. Atlantic view — limited Med detail) doesn't resolve this; warm 500 mb (−5 to 0 °C) over hot SSTs supports afternoon convection near Corsica, Sardinia, Sicily. Change plan if: satellite/lightning shows organised cells on your track.

Routing considerations

Window is open — depart on schedule. The ridge is stable through at least 72 h with no frontal threat. Prioritise:

• Gulf of Lion crossing: transit in the next 36 h while Mistral is moderate (15–20 kt); after Day 3 it may reinforce.
• Bonifacio / Sicilian Channel: benign — take the direct line, expect motoring legs.
• Aegean legs: favour early-morning departures; meltemi typically peaks 14–20 L.
• If the Scandinavian low deepens faster than modelled, stay in the southern/eastern semicircle of any developing Mistral trough — i.e. hug the Spanish/Balearic coast rather than the Golfe.

Advisory only — verify against GRIB updates and local observations before each leg.

Weather Briefing — Med Trip

Snapshot: Sun 16 Aug 2026 16:50 GMT · Area: 34–45°N, 6°W–36°E

Current synoptic setup

The Mediterranean sits under a broad ridge, with the Azores High extending a 1025 hPa tongue across Iberia into the western basin (Chart 1). A weak thermal low (~1010 hPa) sags over North Africa/Tunisia, sharpening the pressure gradient across the Balearics, Sardinian Channel and Ionian. Aloft, the 500 hPa flow is zonal with heights 576–584 dam over the basin — no cut-off lows in the working area. The active weather is well north: a 1005 hPa low near Iceland with a trailing front sweeping the UK/North Sea (Charts 1, 4). Chart 5 confirms clear skies over the Med and cellular stratocumulus in the Atlantic trades — no organised tropical feature threatening Gibraltar approaches. Motion is slow: the ridge is quasi-stationary, the Icelandic low tracks NE.

72-hour outlook

Day 1 (Mon 17 Aug): Ridge holds. Western Med (Balearics–Sardinia): NE 10–15 kt, locally 18 in the Gulf of Lion mistral corridor (Chart 4 shows 16–20 kt streaks off the Rhône). Central/eastern basin: Meltemi NNW 15–22 kt in the Aegean, seas 1.5–2.5 m short-period. Tyrrhenian/Ionian lighter, 8–12 kt. No fronts.

Day 2 (Tue 18 Aug): By 00Z Tuesday (Chart 2) surface pattern near-identical — 1015–1020 hPa across the basin. Mistral eases to 10–15 kt, Meltemi persists NNW 18–22 kt, gusting 25 in Cyclades funnels. Seas Aegean 2–3 m. Western Med benign, NE–E 8–12 kt, seas <1.5 m. No frontal passage in the AOI.

Day 3 (Wed 19 Aug): Ridge slowly retrogrades west; trough digs into Biscay. Gradient tightens west of Sardinia: expect NE 15–20 kt freshening late. Meltemi still 18–22 kt. Alboran/Gibraltar approaches: easterly Levanter building 15–20 kt by evening as Atlantic trough approaches.

Top 3 risks to watch

• Meltemi reinforcement in the Aegean. Charts 1–2 show tight isobar packing between Balkan trough and Turkish thermal low. Uncertain: gust factor in island funnels. Trigger: Athens/Mykonos METAR sustained >25 kt → delay Cyclades legs.
• Levanter build at Gibraltar (Day 3+). Chart 3 (96 h) shows Atlantic trough pressing east, tightening the Strait gradient. Uncertain: exact timing. Trigger: Tarifa pressure fall >3 hPa/6 h → transit Strait westbound before it fills in.
• Mistral pulses in Gulf of Lion. Chart 4 already shows 16–20 kt off the Rhône. Uncertain: whether the next Biscay trough (Chart 3) drives a stronger surge. Trigger: Cap Béar >30 kt or 500 hPa cold pool <560 dam over France.

Routing considerations

Window is open now for western/central Med legs — depart with confidence Mon–Tue. Aegean skippers: the Meltemi is entrenched; plan overnights in lee anchorages, run south with it on the quarter, avoid beating north through Wed. Gibraltar-bound: move west before Wed evening to avoid Levanter build — favour the northern (Spanish) shore to stay on the weaker side of the Strait gradient. Gulf of Lion crossings: do them Mon night into Tue in the mistral lull; postpone if 500 hPa trough deepens on the next run.

Advisory only — verify against GRIB updates, local METAR/METEO France/HNMS bulletins, and your own barometer trace before committing.

Weather Briefing — Med Passage

Snapshot: Sat 15 Aug 2026 16:50 GMT | Area: 34–45°N, 6°W–36°E

---

Current synoptic setup

The Mediterranean basin sits under a broad ridge, with a 1015–1020 hPa surface high extending from the Azores across Iberia into the central Med (Chart 1). Aloft, 500 hPa heights of 576–584 gpdm confirm a warm, stable column — no significant shortwaves crossing the basin at t+0. The nearest active feature is a 1005 hPa low south of Iceland with a cold pool (–25°C at 500 hPa) well removed from the route. A weak Genoa/Ligurian trough is barely resolved. Chart 4 shows light-to-moderate winds across the basin: 8–14 kt general, with a 16–20 kt Etesian/Meltemi tongue in the Aegean (yellow shading east of Greece) and a modest Mistral signal in the Gulf of Lion (~14–18 kt). The Atlantic satellite view (Chart 6) shows no organised tropical or extratropical system threatening the Strait of Gibraltar approaches over the next 48 h.

72-hour outlook

• Day 1 (Sun 16 Aug): Ridge holds. Winds NW 8–14 kt western basin, NE 15–20 kt Aegean (Meltemi steady), light and variable Ionian/Tyrrhenian. Seas 0.5–1.2 m, Aegean 1.5–2.0 m short-period. No fronts.
• Day 2 (Mon 17 Aug): Chart 2 shows the Iberian ridge strengthening to 1020 hPa, low south of Iceland deepening to 1000 hPa — well north of route. Chart 5 confirms Med winds remain 10–15 kt, Meltemi easing slightly to 14–18 kt. Gulf of Lion 15–20 kt NW. Seas unchanged.
• Day 3 (Tue 18 Aug): Ridge axis drifts slightly east; a weak trough noses toward the Balearics. Expect W–SW 10–14 kt western basin, backing. Central/eastern Med benign. No frontal passage on route.

Top 3 risks to watch

• Meltemi reinforcement in the Aegean. Chart 4 already shows 18–20 kt; a tighter pressure gradient between the Balkan trough and Turkish heat low could push gusts to 25–30 kt in the Cyclades funnels. Change of plan trigger: pressure at Athens dropping below 1010 hPa or Meltemi forecasts above 25 kt sustained.
• Gulf of Lion Mistral pulse. Chart 2 suggests slight gradient tightening between the Iberian high and a Ligurian low signature. Charts don't resolve valley acceleration. Trigger: Marseille–Ajaccio gradient exceeding 6 hPa.
• Day 4+ pattern change beyond chart range. Chart 3 (96 h) hints at ridge breakdown as the Icelandic low migrates SE with a 1005 hPa feature near the UK. Not on route yet, but the Atlantic door may open by Day 5–6. Trigger: new run showing 500 hPa trough digging south of 45°N over Biscay.

Routing considerations

Window is open — depart now. The next 72 h are as benign as the season offers across the western and central Med.

• Aegean legs: run them early in the window; Meltemi will not ease meaningfully in 3 days but won't worsen either. Favour lee sides of islands, transit channels at dawn.
• Gulf of Lion crossing: complete within Day 1–2 before any Mistral reinforcement.
• If a system develops later in the trip, favour the southern semicircle of any eastward-tracking Atlantic low (winds veering, following seas) — stay south of 42°N when transiting west of Sardinia.

Advisory only — verify against GRIB and local observations before and during passage.

Weather Briefing — Med Trip, Fri 14 Aug 2026 17:27Z

Note: voyage brief says "April 2026" but chart valid times are August 2026 — briefing follows the chart dates.

Current synoptic setup

The Mediterranean basin sits under a broad ridge, with the Azores High extending east and a 1020 hPa cell centred over the central Med / Italy (Chart 1). The 500 mb pattern shows warm, high thicknesses (568–576 gpdm) across the whole route corridor — a classic summer blocking signature. Atlantic activity is well displaced north: a 1005 hPa low near Iceland/Greenland Sea and a weak 1005 low over the Barents, both far outside the area of interest. A shallow thermal trough runs across Iberia and North Africa (1015 hPa). Chart 4 (GOES full disk) confirms a largely cloud-free eastern Atlantic approach with no organised tropical feature threatening Gibraltar approaches. Motion: features are slow — the Med ridge is quasi-stationary, Atlantic lows tracking ENE well north of 55°N.

72-hour outlook

Day 1 (Sat 15 Aug): Light gradient across the whole basin. Expect NW–N 8–14 kt western Med (Balearics, Gulf of Lion sea-breeze reinforcement possible to 18 kt afternoon), E–NE 6–12 kt Ionian/Aegean (weak Etesian signal). Seas 0.5–1.0 m. No fronts.

Day 2 (Sun 16 Aug — Chart 3 valid): 10 m winds on Chart 3 show the Med in the 6–14 kt band (blue) almost everywhere, with a localised 18–22 kt yellow patch off Portugal/Cadiz — outside the route but relevant to any Gibraltar approach. Aegean shows a firmer NE 14–18 kt streak (Etesian). Seas 0.5–1.2 m; up to 1.5 m in the Aegean funnels.

Day 3 (Mon 17 Aug): Pattern holds. Light variable 5–12 kt west and central Med, NE 12–18 kt Aegean. No frontal passage indicated.

Top 3 risks to watch

• Aegean Etesian reinforcement. Chart 3 shows the NE flow already established; Chart 2 (T+96) keeps the Med ridge steady but the pressure gradient across the Aegean could tighten. Trigger: if 1015 isobar pushes south of Crete on next run, expect 25 kt gusting 30 in the Cyclades channels — reroute leeward of islands.
• Afternoon thermal gales, Gulf of Lion / Bonifacio. Not resolved by 1° GFS wind chart but implied by the tight land-sea thermal contrast (Chart 1, hot Iberia/France under the 500 mb warm dome). Trigger: local METAR/buoy showing >18 kt by 1400L — delay the strait crossing to overnight.
• Iberian trough deepening / Atlantic swell at Gibraltar. Chart 2 hints at a weak 1015 low drifting toward Morocco by T+96. Trigger: if central pressure drops below 1012 or isobars pack west of Gibraltar, expect W'ly swell 1.5–2 m into Alboran — time Gibraltar transit for slack/eastbound tide.

Routing considerations

Departure window is open. Conditions are benign and stable through at least 72 hr with no synoptic threat on the T+96 chart. Favour early departures to dodge afternoon thermal buildup in the Gulf of Lion and Bonifacio Strait. For Aegean legs, run west/south of island chains to stay in the lee of the NE Etesian. If routing via Gibraltar, cross before the Iberian trough sharpens — aim to be east of Alboran by Day 3. No approaching system requires semicircle choice on this route.

Advisory only — verify against updated GFS/ECMWF runs and local observations underway.

Weather Briefing — Med Passage

Snapshot: Thu 13 Aug 2026 17:28Z · Area 34–45°N, 6°W–36°E

> ⚠️ Note: voyage header says "April 2026" but all charts are valid 13–17 Aug 2026. Briefing is written to the chart dates. Please confirm.

Current synoptic setup

The Mediterranean sits under a broad ridge. Chart 1 shows a 1020 hPa surface high centred over the western basin/Iberia, with a 1015–1020 hPa tongue extending east across the central and eastern Med; 500 mb heights are 580–588 dam — a warm, stable summer pattern. The controlling Atlantic feature is a deep 1005 hPa low south of Iceland with an associated 552 dam upper trough (Chart 1), but its trailing frontal system stays well north of Biscay. A weak thermal low sits over Iberia/N. Africa. Chart 4 confirms light-to-moderate flow across the basin, with the strongest signal a green/yellow Etesian-type NW'ly (18–25 kt) funnelling through the Aegean. Motion: the Azores/Med ridge holds and even builds through 96 h (Chart 3, 1025 hPa reappearing west of Iberia).

72-hour outlook

Day 1 (Fri 14 Aug): Western Med (Balearics–Sardinia): NE–E 8–14 kt, seas <1 m. Tyrrhenian/Ionian: variable 5–12 kt. Aegean: N–NNW 20–28 kt, gusts higher in channels, seas 1.5–2.5 m (meltemi signature on Chart 4). No fronts in the AOI.

Day 2 (Sat 15 Aug, Chart 2/5): Ridge strengthens. Western Med: E–NE 10–15 kt, seas 0.5–1 m. Central Med: light and variable, <10 kt. Aegean eases slightly to N 18–24 kt, seas 1.5–2 m. Sea breezes dominate near coasts each afternoon.

Day 3 (Sun 16 Aug, interpolating to Chart 3 at 96 h): Continued ridge; 1020 hPa over most of route. Western/central Med 5–12 kt, seas <1 m. Aegean N 15–22 kt, easing. Still no frontal threat to the AOI.

Top 3 risks to watch

• Aegean meltemi. Chart 4 shows a persistent 20–28 kt NW/N jet; Chart 5 keeps it in by 48 h. Uncertainty is peak gust strength in the Cyclades funnels (charts are 1° resolution — under-resolves). Trigger to change plan: observed sustained >30 kt or building 3 m sea — delay a Cyclades crossing, stage via lee of Andros/Tinos.
• Atlantic trough digging south. Chart 3 shows the 552 dam trough amplifying near 45°N/20°W by Day 4. If it phases faster, a front could reach the Gulf of Lion by Day 5–6 with a mistral spin-up. Trigger: western Med MSLP falling below 1015 hPa in the next run, or 500 mb heights dropping under 572 dam over France.
• Thermal/coastal effects unresolved. Sat imagery (Chart 6) is Atlantic-centred and doesn't cover the Med — no direct verification of convection over N. Africa or Iberia. Trigger: afternoon CAPE >1000 J/kg on next run near your leg → expect gust fronts near coasts late afternoon.

Routing considerations

Window is open — depart on schedule for the western and central Med. Timing points:

• Aegean/Cyclades legs: favour early-morning departures; if routing E–W, ride the meltemi on a broad reach. Stay south of any low (favoured semicircle here is the southern side of the Aegean pressure gradient — lighter, less fetch).
• Gulf of Lion / Bonifacio: benign now, but plan to clear by end of Day 4 before the Atlantic trough (Risk 2) can influence.
• Sicily Channel / Ionian: light winds — motor-sailing likely; conserve fuel for later.

Re-check GFS 12Z + ECMWF before losing connectivity, and validate against local observations underway.