My naive understanding is that the majority of temperature data comes from where humans are: the surface. Hurricanes are 3d, extending up for miles. The models go almost entirely off the surface temperatures, with very very sparse balloon data (which is a poor sample, since a balloon will follow the air it's put in). Wouldn't the whole volume, or at least a little of it, need to be observed, since the energy in that volume is what's powering the hurricane, not the energy on the surface? I would assume this is why the models have trouble.
Satellites also measure the temperature/height of clouds, and there's also some data from aircraft. A lot of commercial aircraft automatically report the temperature/pressure as they fly. The only problem is that a lot of their flight is in the stratosphere, but they give good data in their climb/descent.
Compared to weather balloons, it's quite a bit more data. In the U.S. there are only 91 weather balloon launching sites, so that's 182 observations per day. AMDAR has 700 aircraft, and each one probably makes about 4 flights per day, and they get a temperature profile going up and going down, so that's 5600 profiles per day. There are about 450 airports in the U.S. with regular commercial service, and the majority of these are covered.
My naive understanding is that the majority of temperature data comes from where humans are: the surface. Hurricanes are 3d, extending up for miles. The models go almost entirely off the surface temperatures, with very very sparse balloon data (which is a poor sample, since a balloon will follow the air it's put in). Wouldn't the whole volume, or at least a little of it, need to be observed, since the energy in that volume is what's powering the hurricane, not the energy on the surface? I would assume this is why the models have trouble.