Temperature at Top of Inversion Layer

[Lon33]

Help me remember (or learn) what the significance is of the temperature at the top of an inversion level.

For example, the Area Forecast Discussion for KLAX said that at 1714Z this morning, "there was a surface based inversion with a top near near 1400 ft with a temp of 31 C." The KLAX field level is 128 MSL, and the temperature at field level at that time was 26 C, i.e., less than the top of the inversion.

So, does the 31 C at the top of the inversion mean that the temperature increased from field level to 1400 MSL, but began to decrease above 1400 MSL? Or does it mean that there was a layer of even warmer air above 1400 MSL?

 

[dtuuri]

Temperature is supposed to get colder as you go up. It got warmer. At 1400' the craziness stopped and started behaving normally again.

 

[Todd82]

Help me remember (or learn) what the significance is of the temperature at the top of an inversion level.

For example, the Area Forecast Discussion for KLAX said that at 1714Z this morning, "there was a surface based inversion with a top near near 1400 ft with a temp of 31 C." The KLAX field level is 128 MSL, and the temperature at field level at that time was 26 C, i.e., less than the top of the inversion.

So, does the 31 C at the top of the inversion mean that the temperature increased from field level to 1400 MSL, but began to decrease above 1400 MSL? Or does it mean that there was a layer of even warmer air above 1400 MSL?

Top of the inversion means just that's the top of where the normal temperature profile is "inverted" or backwards. Above that the temperature decreases with height once again.

 

[luvflyin]

Help me remember (or learn) what the significance is of the temperature at the top of an inversion level.

For example, the Area Forecast Discussion for KLAX said that at 1714Z this morning, "there was a surface based inversion with a top near near 1400 ft with a temp of 31 C." The KLAX field level is 128 MSL, and the temperature at field level at that time was 26 C, i.e., less than the top of the inversion.

So, does the 31 C at the top of the inversion mean that the temperature increased from field level to 1400 MSL, but began to decrease above 1400 MSL? Or does it mean that there was a layer of even warmer air above 1400 MSL?

Not so sure the temperature itself is that pertinent, but the difference is and the altitude it happens at. Wind shear and turbulence can be expected there.

 

[Jim Carpenter]

Assuming a standard temperature lapse rate above the inversion, that top temperature could be used as the starting point for determining temp/dew point convergence, and potentially cloud bases.

 

[sarangan]

Help me remember (or learn) what the significance is of the temperature at the top of an inversion level.

For example, the Area Forecast Discussion for KLAX said that at 1714Z this morning, "there was a surface based inversion with a top near near 1400 ft with a temp of 31 C." The KLAX field level is 128 MSL, and the temperature at field level at that time was 26 C, i.e., less than the top of the inversion.

So, does the 31 C at the top of the inversion mean that the temperature increased from field level to 1400 MSL, but began to decrease above 1400 MSL? Or does it mean that there was a layer of even warmer air above 1400 MSL?

This is what the sounding chart would look like for the scenario you describe. The top of the inversion is where the temperature peaks and starts to decline again.

 

[Tantalum]

This is fairly common in these parts.. basically just means it's going to get even hotter when you first takeoff