HIGHLY UNSTABLE (TUMULTUOUS) WEATHER - WHY WE CHOSE TO STAY PUT JUST A LITTLE LONGER

We have been here in Stuart for the last week.  We have had a nice time.  We have accomplished a number of boat projects that needed doing, and we have managed to reprovision ourselves slowly.  We are definitely taking our time.  We have time to kill at this point since Titusville is only 90 miles to the north and we still have three weeks to get there.  So, we are definitely not in any kind of a hurry.

Over the last couple of days, strange weather patterns have been emerging.  I am pretty sure this is a seasonal thing and reflective of the normal patterns for this time of the year in this area.  We are in a transition area during a transition time period.  It would seem that the weather in northern Florida is quite different from the weather in southern Florida.  We are basically in central Florida at this point.  Also, we are moving from winter into spring. 

In this part of the world, not unlike many others, when warm fronts meet up with cold fronts, you get tumultuous weather.  At the least, the weather is unstable.  Many of you know that the quality of the weather in an area is directly related to the position, direction, and proximity of pressure, air pressure that is.  This is a function of surface and air temperature and the mass of the air in question.  High pressure air always flows to areas of lower pressure.  So, if you are on the edge of a pressure zone, be it high or low, you can expect wind.  You might be on the leading edge of a pressure zone or on the following edge.  It makes no difference (except perhaps in terms of the direction of the wind).  There will be breeze.

When you are running in protected waters such as the ICW, the breeze is not as big a factor since the wind has so little water distance to travel over (fetch) that it does not produce much in the way of waves.  It can, however, create plenty of wind "chop".  The National Whatever Service generally describes the conditions to be expected on the intercoastal waters as "smooth", "light chop", "moderate chop", "choppy" or "rough".  Our boat has seen all of the aforementioned conditions.  "Moderate chop" is on the far edge of comfortable, whereas "choppy" or "rough" will have us using our windshield wipers regularly, but nothing gets tossed off the shelves, unless it is on the beam. 

Also, depending on the direction of the winds, it can have a distinct impact on the water levels encountered along the way.  In the Gulf, for instance, a northerly wind will tend to blow water out of the bays and the water levels on the ICW can drop by as much as 2 feet below MLLW.  This is a problem when you have to transit an area in a boat that draws 4.5 feet and the depth at MLLW on the charts says 5 feet. 

I use the word "tumultuous" to describe the weather we are having now.  By that I mean that it is highly unstable and capable of doing just about anything with very little notice.  This condition is characterized by the meeting of fronts.  At this point, we have a cold front (high pressure air) descending from the north (the same front that slammed California several days ago), and a warm front (lower pressure air) ascending from the south.  It is rare for these fronts to meet head on.  Rather, they will "edge" together, and at some point, form a "hook".  Once that "hook" forms, then the two air masses tend to pull into one another with great force while starting to twist in a counterclockwise direction (at least in the northern hemisphere).  In the area of the "hook and twist", conditions ripen for tornadic events and, when that "hook and twist" takes place over the water (usually the ocean), there is a possiblity that conditions will ripen for the appearance of water spouts.  The area behind the "hook and twist", where the two air masses are pulled and smashed together, becomes fertile ground for thunderstorms, possibly severe, including lightning. 

In our case, the northern high pressure flow seems to have stalled just north of us.  The pressure is simply not great enough to push the low pressure southerly front out.  The "hook and twist" is not that far away; there may be tornadoes in northern central Florida -the conditions are right.  The temperature has been rising the past couple days, as has the humidity, and the barometer has been behaving like a "sleenkee".  The two pressure masses are in contact, but the twist seems to be stalled, but it, like a thin flint, is on the verge of breaking.  As a result, the two pressure areas are staying in contact with each other and constantly rub.  You know what happens when they do that - friction.  Friction causes heat.  Heat and friction in the atmosphere causes lightning and thunderstorms.  There are not many birds in the air, and even the ubiquitous mosquito has trouble flying. 

However, if the air masses are not really moving, then there will not be as much friction and heat.  The problem is knowing just when they will start moving.  When they do, it will result in an event similar to an earthquake - a major sheering force will result in a major and rapid dissolution of the weather.  This is what is expected to happen sometime during the next 24 to 36 hours.  And, when it does, it will be like a great atmospheric "breaking of wind", so to speak, and the weather will be quite exciting for several hours.  In the wake of this great barometric flattulence, there will be relief and the weather will get good again.

Air moving behind these frontal zones becomes turbulent and when this happens, you get what the NWS refers to as upper level or lower level disturbances.  This is kind of like the wake from a boat bounding off of something in its path, such as an island, or a breakwall.  The wave is broken, split, or otherwise deprived of its open path where it might otherwise, in the absence of other things, go on indefinitely.  These upper level disturbances, while wonderful for sunrises and sunsets, drive meteorologists crazy.

Presently, the air masses are stalled.  They are sitting high above rubbing against one another.  Sooner or later, something has got to give.  Will it be the high, or will it be the low?  The National Whatever Service thinks it will be the high, and that cold air will descend upon us in the wake of the front which is expected to move east, north-east tonight or tomorrow.  Yesterday, the forecast was vastly different than it is today.  I suspect that, by this afternoon, it will be vastly different than it is this morning.  This is why I call the weather "tumultuous".  It's too unpredictable under the circumstances and is a function of all the variables I have discussed.

What does this mean for boaters?  If you ain't got no reason to be on the water, it is prudent to just stay put.  It is a wise time to make sure you have plenty of anchor scope out (or that you are otherwise securely attached to your mooring ball).  It is a good time to check your chaffe gear, and make sure you are monitoring your weather surroundings.  If you've got a good book you are reading, keep reading.  Some mariners will chose to go.  They probably do well in Vegas given their gambling spirit.  Perhaps they make it unscathed.  Perhaps they get caught.  If they get caught, they'll deal with it.  We chose to wait until the weather becomes more stable.  What's the rush?  If we were heading south, it would not be an issue as we would be moving away from the unstable weather.  We, however, are moving north, and our projected path takes us right into the teeth of tumultuousness.  I ain't no sissy.  But we have another 7000 miles ahead of us in a 29 year old boat.  Just too risky.  By Friday, we should be on our way.  No problem.  We just picked a fresh bottle of Ron Rico and can make plenty of ice.