jinftl wrote:Beautiful day on Saturday....but temps weren't anything except normal to still above normal here in south florida....
AINLAND SOUTH FLORIDA TEMPERATURE AND PRECIPITATION TABLE
NATIONAL WEATHER SERVICE MIAMI FL
1005 AM EST SUN DEC 23 2007
...HIGHEST TEMPERATURE YESTERDAY...LOWEST LAST 12 HOURS...
AIRPORT OBSERVATIONS HIGH LOW
FORT LAUDERDALE INTL 80 69
MIAMI INTERNATIONAL 80 66
WEST PALM BEACH 76 66
Why do you believe this is a consistent annual trend in recent years? Do you think the urban heat island may have influenced overnight lows, thus resulting in above normal temperatures? This has been mentioned in another thread, but I have noticed some decadal changes in the USDA hardiness zones, especially along the east and west coasts of FL. I recently observed a 3-4' coconut palm growing outside in New Smyrna Beach, FL (closer to Jacksonville than Miami) during August without any protection. The Tampa area is much more tropical (vegetatively) than previous decades, largely because of the heat island. Regardless, I think some climatological changes could be influencing the northward migration of plant hardiness zones.
There are other factors that dictate vegetation, including soil content, pH, and climatological precipitation, so there are some complexities that should be taken into accounts. Additionally, some historical decades may have been similar to our current period, so it is hard to pinpoint the "authenticity" of the current warming trend, whether it reflects global warming or local regional changes.
Although this is south Florida, I can't remember too many long-lasting cold events during 2003-2007 vs. the 1990s and previous decades. It could be an illusion, but it seems like the SE ridge has been more persistent in recent winters. The 1970s were a polar opposite of recent years. Note that the 1970s featured widespread cold in the Deep South during several winters. There was the notable January 1977 snow event in south Florida, too.
There are historical accounts that suggest the Saint Johns River (NE and central FL) regularly froze during winters in the 1800s, so there has definitely been some climatological changes in the Sunshine State over subsequent decades.