Cold fronts

A cold front is represented by a blue line with triangles oriented in the direction of the front movement. A cold front represents the leading edge of a cold air mass that pushes it way under a warmer, lighter air mass, forcing it to rise rapidly, as a bulldozer effect. This rising motion often creates towering clouds, showers, or thunderstorms, especially if the warm air is moist. As the front passes, there's typically a sudden drop in temperature, a sharp wind shift (often veering), and a quick rise in air pressure. Cold fronts usually move fast and bring abrupt, sometimes violent weather changes, making them especially important for sailors to anticipate. Wind can shift from SE (Jugo) to W or NW in Bora situations.

Example of a cold front moving over England and Britany on 14 July 2025

Warm fronts

A warm front is the leading edge of a warm, lighter air mass that slowly rises over a retreating cold air mass. Because the warm air ascends gradually, it forms layered clouds (starting with high cirrus and thickening to stratus), often bringing steady rain or drizzle over a long period. The approach of a warm front is marked by a slow drop in pressure, increasing humidity, and winds that back (e.g., from east to southeast). After the front passes, temperatures rise gently, the rain eases, and pressure stabilizes or rises slowly. Warm fronts usually move slowly and bring more subtle but prolonged weather changes than cold fronts.

Example of a warm front moving eastward across Ireland, https://meteo.hr/prognoze_e.php?section=prognoze_model&param=web_fronte_sutra12

When a warm front passes, the changes are more gradual and subtle than with a cold front, but they still can have a big impact on sailing... 

Mesoscale drivers, understanding regional weather drivers in the Northern Adriatic

When the synoptic map shows nothing special, the real action often comes from local and regional weather drivers.

In the Northern Adriatic, weather conditions are often influenced not just by global and synoptic patterns but by mesoscale drivers, regional-scale systems that operate over tens to hundreds of kilometres. These drivers can change wind strength and direction dramatically over just a few hours or even minutes, especially near coastlines and islands.

Understanding these mesoscale effects is essential for safe and comfortable sailing in this highly variable and geographically complex region.

40 knots bora katabatic wind in Senj, while only 10 knots in Mali-Lošinj, 

from Northeast over the Triest and Senj area on 9 June 2025.