Why do we not see storms structured like a strong hurricane over land?



You see storms that have a low pressure center and spin, but you don’t see the iconic tight spiral like you do with hurricanes where there’s an eye of the storm and everything. Why is that?

In: Earth Science

Hurricanes require warm, moist air to form. There simply isn’t enough of that on land, so they peter out. And megastorms such as these never form over land in the first place. But, I assume you have heard of tornadoes which are a more localized rotating storm event. Massive inland thunderstorms can spawn hundreds of tornadoes.

Cyclones happen all over the world, but how they behave depends on how much energy they have.

If they form in the tropics near the US then we call them Hurricanes, in the west Pacific they’re Cyclones or Typhoons. If they form in the North Atlantic and bring lots of snow to the US northeast then we call them Nor’easters.

The iconic tight spiral you see in hurricanes is thanks to the immense energy within them. The warm air circles around the hurricane in tighter/faster spirals as you approach the eye of the storm. In the eye the winds form a tight corkscrew going upwards and this updraft pushes the clouds out of the middle and creates the defined eye and eye wall. The air then moves outwards and cools and falls in bands creating the rain bands that you get with hurricanes and creating their distinctive shape.

The more energy that the storm has, the more water and wind are involved and the crisper these effects are. One of the big things the NHC looks for when moving a storm from a tropical depression to a tropical storm is the formation of an eye wall, once this forms it helps hold the storm together.

Tropical cyclones have massive amounts of energy to gather up. Atlantic hurricanes have the shortest run to gather energy but even they generally get a couple thousand kilometers to gather energy from warm surface waters (30C+). Pacific Typhoons can be massive with Typhoon Tip hitting 2,220 km in diameter since there’s just massive open ocean with very few islands or ridges to break it up.

Extratropical cyclones (nor’easters) can still get the banding effect if they’re strong enough but they get their energy from high/low pressure differentials and don’t get to build up over thousands of miles. Their lower energy means less total precipitation (hurricanes can bring 1m+ of rain, 1m of snow is considered huge) and much much lower winds.