The Rain Season

Contents:

Introduction

When is the rain season?

How does this affect our fishing or other daily activities?

Heavy rainfall and fishing:

Why do we not get hurricanes?

Storm Preparation

Introduction

It is incredible how many people will not visit our coastal vacation spots during our “rain season”, even though they may actually get as much rain as we do where they live. These people visualize monsoon downpours lasting 24 hours a day for weeks on end…with very little break in the action. The bad news for these people is they are ill informed. The good news is I am about to enlighten you. To me, living full time here in Ixtapa / Zihuatanejo for over 16 years now, the rain season is the best time of the year for me. I really look forward to it.

My training is as a civil engineer, contractor, turned sport fishing captain, fly fishing guide, author. Because of my formal education, and original calling in life, I have been keeping rainfall records for all of the 16 years I have lived here, the dates, and the hours of duration. I moved here in August of 1998 and had brought my trusty 6 inch capacity rain gauge from Southern California with me.

About 3 weeks later, during early September, the tail of a hurricane had whipped over the land, and stalled. The hurricane was being pushed further offshore by factors which I will explain later. My “trusty” 6 inch rain gage was filled and overflowing in the first 4 hours. Being it was early morning; I went out and reset it (I dumped the water out). Four hours later, it was over flowing again. This really upset me being I didn’t have a clue as to these conditions and what was happening.

Among the stuff I had brought down from California was a clear plastic tube of 3 feet long and 2 inches in diameter. I threw my “trusty 6 inch rain gage” in the (wet) trash, glued on a base to the 3 foot tube, and set it out. I had two thoughts while doing this. The first one is I was way over my head (pun intended) with the rainfall here. The second thought was my boat was on the trailer and parked in front of the house. If the damned rain got over the 3 foot tube, at least we had the boat.

During this stalled tail of the storm, and most important, there was no wind, we recorded 48 inches of rain in 4 days here. The government sent in troops to help the washed out home owners who illegally built high up on the hillsides, with no thought to drainage. A lot of homes were literally washed away, with our cleaning lady having one of those homes. With any measurable wind, it could have been a real disaster.

It was a heck of way to break me in to living here, but we have not have had anything like that since. It was a great opportunity for me to open my eyes and understand what can happen here, and how to prepare.

Let’s go back to the “wind” situation. We can, and do, get a lot of very intense rainfall. I consider a 6 inch rainfall in 4 hours a very good amount of rain for us. But, if there is no wind, there is no damage done, because this coast has existed for millennia, and runoff is all taken care of in a few hours. Now, here is the kicker…Almost 90% of our rainfall durations come between 7:00 in the evening and 3:00 in the morning. Because of the Sierra Madre Mountains close behind us, our weather here is dictated 100% by the ocean and the currents. The 9,000 foot Sierra Madres block any influence of Mexico’s mainland weather patterns. If the water is 82° or more, we get thunderstorms.

Even though our thunderstorms rarely have wind of any magnitude or duration, I can also recall many exceptions to the rule, but again they were spread out over 16 years. I remember Paul Phillip’s Fintastic 100% Tag and Release Tournament for sailfish, when a huge storm, with wind, moved in on us. The storm lasted all day on November 9, and wiped out the fishing for inshore and offshore.  The storm even moved a sailboat off its anchor and beached it next to the municipal pier.

Another time, in mid-October, I was the director of Baja On The Fly’s roosterfish tournament for fly fishing roosters and jack crevalle. During our first evening’s Captains Meeting / dinner, the hotel got an emergency fax on a weather update to close everything down and batten up. It went from a clear and beautiful evening, to a torrential downpour. There was about 12 inches of rain in 6 hours, with no previous warning. It was kind of like a tornado situation, with hotels in Ixtapa losing tables and dishes on the ocean fronted restaurants. We were wiped out as an inshore tournament, because the heavily silt laden rivers, carrying a huge volume of water in a very short time, dirtied up all the inshore waters for miles to the north and south. As a side note…we also lost about 20% of all the trees here in Zihuatanejo and Ixtapa during this intense storm, which had gusting winds of almost 90 mph. being it was near the end of the rain season, the ground was already saturated. About 1 in every 5 trees was either knocked over and laying in the street, or had huge limbs torn off. I was really impressed by how the local city government had the whole thing cleaned up and hauled off in two days’ time.

Plus, I remember a day in February just a couple of years back. We got 12 inches of rain in an 18 hour period. I had never seen rain in February, yet alone so intense.

            

When is the “rain season”? As shown above, there are always exceptions to the rule, but our “normal” rainfall year sees about 50 inches of rain between June and the middle of October. This can be summarized as about 10 inches in June, and another 10 inches of rain in each of the months of July and August. September, and a little into October, is where we get about 20 inches of rain, and often will get three to four port closures due to the rains coming during daylight hours. These intense rains are often the tail of a named storm swinging over us, with the eye of the storm being a hundred miles or so offshore.

Our first light rain starts about the last week of May, with most of the heavy stuff, with lightning and thunder being up in the 3,000 to 7,000 foot Sierra Madres just back behind us. And, all of this usually happens late at night (remember this statement). After about June 10 we can expect our rain season to kick off in earnest. The thunderstorms usually give us between a half an inch to 2 inches, and spread out over 2 to 3 hours. The rain generally comes at night, and maybe in back to back increments of 2 to 3 nights in one week. Then we get nothing for another week or so.

But, what we do get is a countryside with a thousand shades of green. After the end of a normal rain season, we may not get another drop until early June. In the dry months, the surrounding hills and countryside turn an ugly brown and dust has settled on everything. By no later than June 20, after a few good rains, the hillsides become vibrant and alive, and explode into all shades of greens and various colored flowers.

During the rain season we get some incredible sunrises as last night's rain clouds dissipate once the sun touches them.

How does this affect our fishing or other daily activities? A typical fishing day will see us going to the municipal pier in Zihuatanejo at dark thirty in the morning. The streets are still wet from the previous night’s rain, and there may even be lightning flashes in the sierras or far out on the ocean. We head out and fish, enjoying a great day on the water, with all thunderstorm activity dispersing once the sun touches it. About 2.00, when we are back at the pier, we notice a lot of large cumulus clouds developing, and stacking up against the sierras. In this way, the Sierra Madres assist in our weather pattern. As the day lengthens, the clouds keep stacking up, trying to rise up and over the sierras. The only way they can get lighter, to rise higher, is to drop their heavy burden of moisture, which they eventually do. As the clouds keep stacking, this happens in the afternoon in the sierras, and later in the evening or night on the coastal plane.

Heavy rainfall and fishing: When we get rainfall of 6 inches in 4 hours, or similar large quantities in short durations, the numerous rivers and streams on this coast handle it well, but they are heavily laden with silt and debris. This does several things, and happens about once a month, but keep in mind once the normal conditions have returned, it will be business as usual.

1) The heavy influx of cold fresh water will move the blue water, which had been on the beach a day earlier, sometimes clear out to the 20 mile mark. This makes for tough blue water fishing with a fleet which is geared up for fishing a normal day in the 12 to 18 mile areas.

2) For the inshore fisherman, especially for the hard fighting roosterfish, he is going to be out of luck for a few days and until the clarity and salinity comes back. Plus, the most productive area to catch roosters is along the shoreline, on the back side of the waves. The fresh water sits on top the salt water, and gets mixed up by the pounding surf, lowering the salinity. Roosters are not like snook, which do well in brackish water, so the roosters go out to the deeper water and wait it out. A few days later they will be back on the beaches.

  

3) The rivers are also heavily laden with debris from trees, aquatic plants and other vegetation. This makes for a nasty mess when the weed infested offshore areas are broad, fouling the trolling lines. But, once the currents take over, and the weed lines form up, the dorado are attracted in huge numbers.

  

Why do we not get hurricanes? One factor a lot of people are justifiably apprehensive about is the possibility of being caught in a hurricane. Several times a year we have hurricanes form right off our coast and out about 200 miles. You can watch them on the satellite maps with one hurricane northwest of us, another a couple of hundred miles to the southeast, and us sandwiched in the middle.

But, when you talk to the locals, they just shine them on. This is because in their lifetimes, we have never been hit by a hurricane. However, the year before I moved here to Zihuatanejo, Acapulco got hit head on by a hurricane, causing a lot of property damage and deaths. Why we have never been hit, when for 16 years I have observed at least 5 or 6 hurricanes a year forming out in front or just to the south has always bewildered me. The engineer in me tells me it is only a matter of time before it does happen. Then one day I had the fortunate luck to fish with a meteorologist from the NOAA (National Ocean and Atmospheric Administration).

While discussing this perplexing problem with him, he told me that (once again) the high Sierra Madres are our friends. He stated the high pressure in an area needs to break down before a storm can move into the area. As the high pressure over our small coastal plain breaks down, like the water it moves in front of it creating tide surges, the hurricane also moves a huge mass of air. With the hurricane on one end, Zihuatanejo in the middle, and the Sierra Madres at the other end, the air is compressed against the sierras. This creates an artificial high pressure zone, and the storm bounces back out to sea. It will usually repeat this scenario a few times before finding a groove and heading out west to die in cooler water or slamming into Cabo San Lucas or other points north.

But, while the storm and the Sierra Madres fight over property rights, the tail can stall over us, like it did in early September years ago, and Zihuatanejo can get a lot of rain. So the storm does get a bit of satisfaction while the sierras just remain majestically silent.

Storm Preparation For those of you who own property here, and even those of you who are guests, please remember these points. Most significant is when the electricity goes out over a widespread area, all services are also gone. And, even though I have yet to see it, a major storm with wind, can knock out the electricity in a broad area for a week or more.

Just imagine the things you will not have without electricity. Banks will be closed because the computer system will be down, and you will have no ability to get cash. Gas for your vehicle will only be what is in your tank, because the pumps will not function at the gas station (unless they have a generator like they have at the gas station near Buena Vista on the road to Troncones). The larger supermarkets will be closed because their checkout scanners and cash boxes will not function, leaving you to buy necessities from the low inventory small mom and pop stores, which the locals will deplete rapidly.

In your home you will have only the water in the tinaco (tank) on the roof. You pressure pump or the ability to get water out of the cistern will not be available, other than a bucket. Plus, the street water service will no longer exist; because the municipality’s well pumps have no electricity. When your existing supply is gone, you will have no water. Even bottled drinking water will no longer deliver, because they need electricity to run the pumps and the osmosis process.

 Your refrigerator will be useless, and unless you cook up the food, it will have to be thrown away, and even then, cooked food will not last long. And, can you imagine how miserable it would be without even a fan when the humidity is 90%. About the only thing you have which will function normally is your stove. We use propane gas here, and as long as the bottle or tank it is near full, it will last weeks. And, you can at least boil your water for drinking.

Fortunately with today’s computer and satellite service, we have plenty of warning when a major storm is developing and starts to move. Here are three excellent web pages I utilize daily during the rainy season: The first is the NOAA hurricane center 
http://www.nhc.noaa.gov/index.shtml?epac 
The NOAA page gives excellent data for named, or developing potentially named storms, Their paths, intensity, and locations.

The second is the Weather Channel for Mexico  http://www.weather.com/maps/geography/northamerica/mexicosatellite_large.html
This web page gives a decent view of what is actually going on the overall picture, and what you can possibly expect for the next 48 hours. The data is usually just a few hours old. The view is for all of Mexico.

The final web page is Weather Underground.  http://www.wunderground.com/global/stations/76758.html
The data on this satellite photo is usually no more than 3 minutes old. And, by clicking on the photo, it will scale down to a small map showing just our area, and about 50 miles to the north and south. When looking at the forecast on this web page, it will almost always indicate 20% to 40% chance of rain or thundershowers. The forecast is correct, but you would be incorrect assuming this is for Ixtapa/Zihuatanejo. Also included in our "area" are the Sierra Madres, where the rain will fall first. If it does make it down to the coastal plain, it will probably be at night anyway, so don't cancel a vacation because you think it will be raining the whole time.  

When I see a potential threatening storm, the first thing I do is I go to the bank and make a substantial withdrawal. Cash will be needed and plastic will not work. Then I top off my Suburban with gas and fill a couple of 40 liter containers for extra fuel for my small generator I have at home. The small light plant will power a couple of the new style fluorescent light bulbs, the fridge, and a fan.

I always have 3 jugs (garafons) of drinking water, but water is not a problem for me, as I have an open well. I can get all the water I need as long as my arms hold up from lifting the bucket.  

I also check to be sure my pantry is well stocked with canned goods, rice, beans, and other long lasting foods. 

The locals think I am crazy, but I do not want to stop this routine, because the one time I do…is when we will get slammed.

Oh, and my 3 foot long plastic rain gage of several years back… has been replaced with a straight sided 5 gallon bucket I set on an unobstructed high point. It works well….So far.

Ed Kunze