Science infographic prompt, landscape 3:2. A friendly flat-style infographic explaining how a cold wave forms, on a clean cream background with an ice-blue and warm-orange palette. Large title at the top reads HOW A COLD WAVE FORMS in bold navy letters. Four rounded modules in a row, connected by small orange arrows: first, a cold air mass gathering over snowy Siberian plains labeled COLD AIR; second, a high-pressure system pushing the cold air south labeled MOVES SOUTH; third, a cold front meeting warm air with wind swirls and snowflakes labeled COLD FRONT; fourth, a big thermometer plunging down labeled TEMPERATURE DROP. Simple flat illustrations, a small map of northern Asia with a curved arrow, tiny snowflakes and wind lines, short labels only, clean spacing, no long paragraphs, no logos, no watermark, crisp vector style.