In fact, you can have a very nice weather in a high pressure zone, with clear sunny sky and little wind, but during daytime, the pressure drops a little to climb up again during the night. That is a normal diurnal variation of pressure; when it is hot, air rises and pressure drops a bit. It is not the drop in itself but the rate of fall that is the most important point and that's why some people have barographs that register the pressure over time. An old seafarer's rule is that a pressure fall of ten millibars (today, called hecto-Pascal) in eight hours is a certain sign of a gale force wind coming in. And that is the only thing that is 100 percent certain in meteorology; a pressure fall must be followed by a wind of air trying to fill again the lower pressure.
Causes Of Enlarged Kidneys In Fetus. While in some cases, enlarged kidney may not be associated with any apparent cause, there are some common causes that have been identified, Vesicoureteral reflux: This condition is associated with faulty functioning of the valves which are present at the juncture of the ureters and the urinary bladder.
hydronephrosis of the working kidney. A baby with kidney dysplasia in only one kidney might have other urinary tract defects. When other defects in the urinary tract block the flow of urine, the urine backs up and causes the kidneys and ureters to swell, a condition called hydronephrosis.