yeah, blog post titles are getting cheesier by the day........what can i say?........hope it's at least a little more exotic than, say, cheddar or american or swiss.............ultimately, however, i think this one's fitting....we'd better start swimming or we'll sink like a stone......................................................
you know what prompted this post? the local weather guys; and in particular the two younger guys (one on each of lafayette's 2 big stations)...........as this summer wears on, they conclude on just about every weather airing: "well, that's just south louisiana summer weather for you.....heat and humidity....."
having spent most of 50+ years living here, my conclusion re: present-day summer weather is different from theirs...........what we're seeing/feeling here in summer 2010 is not at all "typical," for our region; nor have any of the past 12 summers been "typical".
here in south-central louisiana, our typical summer climatic picture most often began (like beginning in late may/early june) with a dominating, temperate high-pressure dome centered somewhere around colorado or wyoming, and another way east, centered around bermuda...............winds move clockwise around high pressure domes, thus south louisiana was a battle-ground between drier northerly breezes coming off the continental dome, and wetter southerly breezes coming off the bermuda high...........most often, this pattern would result in an isolated to scattered thunderstorm pattern each afternoon, where hotter/wetter air came up north out of the gulf (the "seabreeze effect"), condensing into enormous clouds as it piled on top of the gentler, drier breezes coming down from the north..............................
these days, we are not dominated by a temperate high to our northwest and a temperate/sub-tropical high to our east......................................we are instead dominated by a massive, squishy, tropical high to our south.........all summer long, this tropical high pressure dome expands and contracts, sometimes (as it is now) bulldozing its northern edge all the way up into the midwestern u.s.; sometimes only as far north as the mid-south; sometimes only as far north as our gulf coast.............the tropical air that it brings is far warmer and wetter than anything we ever got from the "old" bermuda high, often carrying this tropical air far north of louisiana (as it presently is), wreaking havoc at the border where the northbound tropical air meets with the stationery temperate air..................
often, the north-central gulf coast sits directly under this big tropical high-pressure dome for days or weeks at a time.....................so it's like we're sitting in a pressure-cooker.......the tropical high pressure directly above us stymies vertical cloud formation; so we get clouds, but most of them cannot build up high enough into the cool upper reaches of the atmosphere (say 20,000+ feet) to condense into thunderstorms......more often than not, we just sit here, cooking, whilst storm tracks form well to our north and to our south.........................................
when we do get rains, more often than not they are tropical rains, gushing down at rates of 1-2" per hour.....and more often than not, these rains are the result of tropical/nearly tropical waves rolling in from the south, "denting" the soft, squishy tropical high-pressure dome above us for a few days at a time, and bringing scattered torrential rains in the process..............and this general pattern is not confined to the summer months only...............last january 12, for example, we went to a john prine concert in new orleans......a low-pressure wave rolled in from the southeast, dropping 5" of rain onto canal street in about 3 hours.......
in short, this dominating tropical high-pressure dome oscillates north and south on a year round basis; but seems to spend more and more time centered over the gulf of mexico (instead of well to the south of the gulf, back in the day)...........................................
for us, the result of this northward shift in tropical high-pressure dominance is a corresponding northward shift in general weather pattern, or climate...............i believe that we can actually trace its beginnings to the end of the spring of 1998, when we (the u.s. gulf coast) fell under a killer-drought...........from may 1998 through october 2000 it didn't rain much here; and average rainfall totals per rainfall episode dropped dramatically as well...............from 1998 through present, we've been getting way more 0.25-0.50" rains; and whenever we get a more substantial rain, it's usually at or over the 1.5" mark..............bottom line: it don't come like it used to; and when it does come, it comes in buckets.................
back around 2000 i remember writing that our lafayette weather was more and more resembling that of corpus christi.......hotter, more humid air with longer periods of very little or no rain, punctuated by the occasional frog-strangler..............................................................presently, i stand by that conclusion, as for the past 10 years (with the exception of 2004) this same generalized climatic pattern has endured.................................................the climate has changed, ya'll.................................
to all who disagree with my assessment, no hard feelings, ok? nevertheless -- and please don't take this personally -- only the malinformed would believe that the billions of tons of carbon-dioxide and other waste gases that we've ADDED to the pre-industrialized global atmosphere -- particularly over the past 60 years (think: in any given moment, how many jet aircraft are taking off, how many coal-fired electrical plants are burning, how many automobiles are running [tens of millions in the u.s. alone are sitting parked at drive-thrus as we speak], lawnmowers?, how much slashing and burning in the tropics, etc etc etc) has not resulted in any appreciable change in our global atmosphere.............................................our (humanity's) waste gas output has climbed through the roof........................with no apparent effect in our global atmosphere?
besides my relatively haphazard conclusions based on local rainfall amounts and intensities alone (admittedly shaky ground to be making such statements; but hey, i'm pretty sure i'm a weather savant....), some of us have also noticed a northerly shift in the distribution ranges of a number of tropical/sub-tropical animals.......... over the past 10-20 years around lafayette we've watched white-winged dove, inca dove, brown widow spider, and rio grande chirping frog all establishing permanent homes here...........in new orleans, add greenhouse frog and cuban anole to the list.....................
are we in some pathologic state of denial or what?
the climes are indeed changing...................................................and allow me to end with some real dylan:
"Praise be to Nero's Neptune
The Titanic sails at dawn
and everybody's shouting
'Which Side Are You On?' "
(--from 'Desolation Row')
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