Rain-shadow tendency
Leeward of the mountain
A LITTLE CURIOSITY. A WHOLE NEW ATMOSPHERE.
Brainstorm.
Build a weather world.
Move the city. Shape the land. Change the wind.
Discover why the weather takes a different turn.
YOUR WORLD, YOUR WHAT-IFInteractive learning sandbox
Start somewhereLooking for Pattern Finder? ↗
LIVE EXPLORATIONIllustrative cross-section · not to scale
Drag the city, mountain, or lake handle. All positions are also adjustable below.
FOLLOW THE CHAIN REACTION
What changes for your city?
Your city sits behind the mountain. Air rises on the approaching slope, then descends toward the city; warming as it descends can reduce cloud formation.
Inland temperature swings
Water changes temperature more slowly than land. Airflow and distance affect its reach.
No lake in this world
Cold air + relatively warm open water + a downwind city. These ingredients allow snow; they do not guarantee it.
Keep a world. Change a variable.
Save this version, then experiment to see what changes. Saved on this browser.
What this world can teach you — and what it leaves out
This is a qualitative teaching model, not live weather, a climate projection, or a forecast. Position and height controls are abstract diagram units. Cloud icons show a mechanism that can favor cloud formation; they do not show measured cloud cover. The diagram is a single cross-section with fixed airflow and no time evolution.
Mountains can lift moist air and favor precipitation on the windward side, while descending air can produce a rain shadow. Near a coast, water can moderate temperature swings, particularly with onshore flow. In the cold scenario, an open lake is assumed warmer than the incoming air; freezing it removes that moisture source. Wind speed, stability, actual temperatures, lake fetch, fronts, storm tracks, and precipitation amounts are not calculated. A mountain between the lake and city marks an interrupted path rather than predicting lake-effect snow beyond it.
Learn more: NWS · airflow over mountains · NWS · lake-effect snow. For observed patterns, try Pattern Finder in In-depth Data Analysis.