March 13th radiosonde launches

March 13th 8PM radiosonde launch

An inverted-V sounding demonstrates the dry air in the lower levels. The weak southeasterly winds at the surface did not cause any problems with the balloon and tower. The winds in general were weak at the low levels. As expected,  the nighttime inversion has started to develop in the boundary layer. The height of the boundary layer extended to approximately 610mb. 

March 13^th 4PM radiosonde launch

 

The most notable feature is the extremely dry layer around 500mb. Again, winds were light and northerly at the surface with a shift to northeasterly and then to west south westerly through the column. Clouds are more sparse and higher in altitude than at noon.

March 13th 12PM radiosonde launch

Downslope winds from the morning helped dry out the mid-levels which caused the stratus layer to dissipate. With fewer clouds, solar radiation eroded the earlier inversion. The boundary layer extended up to 750mb due to ample heating. The winds up to 350mb were northwesterly with a shift to southwesterly/westerly above this layer. Some convective clouds started to form (see image below). 

 View looking southeast from the BAO visitors center at noon.

March 13th 8AM radiosonde launch 

The day started out cool with a layer of stratus clouds. A shallow inversion was still visible near the surface. The air column was above 50% relative humidity up to 300mb, with a saturated layer between 700mb-610mb, which dried out by the noon sounding. Winds at the surface were light and westerly. Just above the surface, winds quickly changed to a more northerly direction and then again to a westerly direction.