In the past, I haven’t written a lot about weather (other than a lightening strike), so now is the time. Disclaimer first, I’m going to keep this as simple as I can to avoid boring you. I consult way more resources than what I have listed here.
When you live on a boat, one of your daily jobs is to check various weather sources. The sources range from large scale modeling to local temperature forecasting. Interpreting these sources allows us to get a picture of not only what our day will be like, but what we can expect in the next 5-7 days. Unfortunately this week, the large scale models are showing some concerning things. I thought I would take this as an opportunity to talk through and explain why its concerning and what our options are.
So… The first resource we consult is a website (http://www.spaghettimodels.com/). Its run by a fella called Mike and is an awesome resource. Mike has essentially taken all the important resources on the Internet and consolidated them in one location. Here is a screenshot of the website.
Although it looks very busy, the essential information is front and center. We are most interested in the 2 images in the center and the Facebook feed to the right. The Facebook feed is live and changes as Mike assess the various resources and gives opinions on the situation. You will notice the lower image today has a big red cone over the map. Unfortunately this is exactly the thing we DO NOT want to see. Since those images are pulled from the National Hurricane center’s website we can click on them to take us there where we can further interpret what it means.
Once over on NOAA website we get a close up of the image as well as a professional forecaster’s opinion on the situation. In this situation, we are interested in the text labeled as #1. Here is an excerpt of the text:
“Disorganized showers and thunderstorms associated with a tropical
wave located about 1000 miles west-southwest of the southernmost
Cabo Verde Islands is moving westward at around 20 mph.
Environmental conditions are expected to be conducive for gradual
development of this disturbance, and a tropical depression is likely
to form later this week. Interests in the Windward Islands, the
southern Caribbean Sea, and the northern coast of South America
should monitor the progress of this system.
* Formation chance through 48 hours…low…20 percent
* Formation chance through 5 days…high…80 percent”
So as you can see, there is a “Tropical Wave” out in the Atlantic moving westward towards the lower islands (including Grenada) at about 20mph. The forecaster has put the likelihood of this wave forming into a “Tropical Depression” at 80% within 5 days (could happen sooner). My experience with NOAA shows that they always underestimate the probability. So I interpret this %80 as a %100. The next question I can hear you asking, “What is a Tropical Depression”. The escalations of storms is as follows.
Tropical Depression – 25-35mph winds (possible to ride out on a mooring ball)
Tropical Storm – 40-75mph winds (look for hidey hole in mangroves, tie up really good)
Hurricane 1 – 75-95mph winds (probably still ride in mangroves but not on board. Safely ashore with fingers crossed POF is unscathed)
Hurricane 2 – 96-110mph winds (some onshore damage likely)
Hurricane 3 – 111-130mph winds (massive onshore damage likely, boat loss likely)
Hurricane 4 – 131-155mph winds (massive onshore damage guaranteed, boat loss assured)
Hurricane 5 – Over 155mph winds (state of disaster, boats rarely survive this, pants pooping scary even on land)
So, we have a predicted tropical depression that appears to be passing right over the top of us…. Not good. However, that NOAA image is a very loose prediction and has a wide cone of potential path. That prediction is just not good enough for me as even 20 miles can make the difference of a “little wind” or “holy hell, its blowing like stink”. Unfortunately we (humans) have no solid way of predicting the path but super computers around the globe do their best and we can use these predictions to further zoom in on the potential track. The image below is a super computer prediction map (pulled from lower down on Spaghetti Models website).
Each of those lines are a computer model prediction (see why the above website is named Spaghetti Models?). Now that looks a little better as most of the predicted tracks are north of us. Now keep in mind, these are just predictions and historically not super reliable until the storm is about 2 days out. However, this makes me a little relieved as for now the odds are in favor of a miss on Grenada. You can bet your sweet patootie that I will be watching these models like a hawk over the next 4 –5 days. By Monday afternoon the models should be reliable enough that the path will be somewhere between the outer spaghetti lines.
The other thing in our favor is the speed at which the storm is moving. As long as it doesn’t massively speed up we will be hauled out and safely on the hard (strapped down) if/when it passes over. Although this won’t help our friends and neighbors that are in the bay. For them, they can use the above spaghetti models to make a decision on whether to site tight or run out of the path. If they do run, then these models will help them decide when and which direction to run.
As we have said over and over, “Its not all coconuts and rum drinks”! Wish us luck.