Diego From Italy, joined Apr 2001, 135 posts, RR: 0 Posted (10 years 1 month 2 weeks 3 days 16 hours ago) and read 1191 times:
Hi guys I am not sure if this question entirely fits this forum anyway I will post: if I can recall correctly the pressure at the passage of a cold front increases and then decreases while the opposite occurs in a warm front where as the front approaches the pressure decreases. Well it seems like I ma having an hard time to remeber the reason why this happen especially referred to the cold front. Another question how does the wind changes in a warm front and in a cold front and if it veers or backs, which one would be the reason for that happening? Also the temperature changes related to the fronts sort of puzzle me, not so much concerning the warm front but the cold front.
Thanks for your willingness.
AirWillie6475 From United States of America, joined Jan 2005, 2448 posts, RR: 1
Reply 1, posted (10 years 1 month 2 weeks 3 days 1 hour ago) and read 954 times:
As a front approaches, atmospheric pressure usually decreases, with the area of lowest pressure lying directly over the front. Pressure changes on the warm side of the front generally occur more slowly than on the colder side. When you approach a front toward the cool air, pressure drops slowly until you cross the front, then rises quickly. When you are crossing toward the warm air, pressure drops abrubtly over the front and then rises slowly. Remember warm air is less dense than cold air. Also cold fronts are pushed by intense high pressure systems. That is why after cold passage the pressure rises.
Wind Cold Front:
Prior to passage of front winds are SSW(south,southwest). During passage varable and after passage, WNW.
Wind Warm Front:
Prior to passage SSE, during passage variable, after passage SSW.
Temperature changes because the front introduces a different temperature to the local area. You notice a change in temperature on a cold front because they move faster.