weather watch Ron Bianchi
Technology has greatly changed the world of weather for the avid sailor in the
last 10 years. It’s now more convenient to look at our phone screens rather
than up to the sky for our weather information...But what do you do when
you lose power and your technology is not available?
RON BIANCHI,
GRAPHICS and
PHOTOGRAPHY,
ALICJA PARLAK
Technology has greatly changed the world of weather for the avid sailor in the last 10 years.
It’s now more convenient to look at our phone screens rather than up to the sky for our weather
information.
Thanks to the Internet, we now have access to a huge amount of weather data, as well as
forecasts, whenever we want them. Cell phone technology has grown by leaps and bounds in the
last few years, and now, with the latest smart phones and tablets, we all have super computers in
our pockets with the ability to access and process weather data like never before. These gadgets
have revolutionized our everyday lives and changed how we look at the weather.
But as I teach my weather courses and provide pre-regatta weather briefings throughout the
Greater Toronto Area, the question I get asked most often has nothing to do with the latest
website or app. Sailors just want to know if there are simple visual clues, in the clouds, that can
tell them what may happen weather-wise in the next few hours.
Cloud observations have been one of the most reliable predictors of local weather for centuries,
and have been proven to add value and help the sailor navigate the water in the near short term
and even as far out as 24 hours.
12 BOAT SHOW 2017
Say you saw it in GAM
To follow these cloud clues, the first thing you have
to understand is that there are mainly just three types
of clouds that you, as a sailor, need to worry about. The
first are the wispy, hair-like strands of high clouds, called
cirrus, followed by the layered, flat, “bed sheet” clouds
called stratus, and, finally, the famous cotton ball or
cauliflower shaped clouds called cumulus.
The thing to remember here, no matter which type
you’re looking at, is that the more clouds you see filling
the sky, the more unstable the atmosphere is, and the
greater the chances are the weather will change. The
fewer clouds you see, the drier and more stable the
weather is and it will probably stay the same for the next
24 hours.
Here are just a few rules of thumb that you can easily
follow to get a better picture of how the weather may
play out for your time on the water.
CIRRUS AND CONTRAILS
One of the best clouds to indicate weather change in
the next 18 to 24 hours is the cirrus cloud. It usually
invades the sky from the west into the southwest
quadrant, and continues to build and thicken into a thin
wispy veil. This usually indicates a weather system is on
the way and should affect the area in the next 18 to 24
hours. Cirrus clouds always ride ahead of active weather
systems so they are a great indicator to you that some
type of active weather is on its way.
Cirrus 1
If you don’t see any clouds in the sky, look for some
contrails. These aviation exhaust trails are really nothing
more than man made cirrus clouds, and they can also
indicate a change in the weather. If a contrail behind a jet
disappears quickly, it means that the air aloft is very dry
and is sinking, which is not conducive for weather system
development, so the weather should remain the same for Lakebreeze
the next 24 hours.
If the contrail lasts for more than an hour, widens and
has the appearance of a snake slithering slowly across the
sky, then a change in the weather should happen in about
24 hours. I have tested this rule of thumb many times
and it verifies quite well.
LAKE BREEZE AND THE CUMULUS TELL
There are many challenges faced by the long-distance
sailor on the Great Lakes, but a very specific local
weather phenomenon has proven to be one of the
greatest. The lake breeze usually occurs in the summer
under a weak, slack weather pattern. High pressure
moves in and flattens the wind gradient, and it becomes
difficult to have consistent wind. When winds die out
in the middle of the lake, look towards the shoreline for
answers. Small stationary cumulus clouds dotting the
Say you saw it in GAM Contrails
BOAT SHOW 2017
13
shore, without any other clouds present around the mid-lake
area, are your visual clue that you’re sailing in a lake breeze
situation. If you see this, just head towards the shoreline as
most lake breezes get stronger around three to five nautical
miles of shore.
THUNDERSTORMS AND SQUALLS
Thunderstorms and squalls are produced by very active
and rapidly vertically growing cumulus clouds. These
clouds then become huge towering cumulus and evolve into
cumulonimbus or thunderhead clouds. These can become
a real threat for the average boater. Unlike other clouds
(especially the cirrus and stratus clouds), which can give you
several hours notice ahead of a weather change, the clouds
in the cumulus family develop extremely quickly, often in
the tens of minutes, and before you know it, you’re faced
with strong gusty winds, heavy rain and lightning.
So how do you give yourself a little extra time? Look for
large, vertical cauliflower-shaped clouds. If you see these
classic big thunderheads in the area south and southwest of
your location, pay close attention, as they are most likely
heading in your direction; these clouds usually move from
the southwest towards the northeast. If you see one well
north of you, you should be OK.
Keeping a close eye out for a few subtle clues can also help
you gauge the severity of the oncoming storm. Pay attention
to the colours of the clouds. The darker a cloud is near its
base, the stronger the storm. Look for green and yellow
tints midway up the cloud. These also indicate a powerful
storm system. The lightning flash rate is also another good
measure of storm severity. If you see a lightning flash every
two to three seconds, this is not your regular garden variety
storm. Remember, by the time you see that pitch black base
to the south or southwest of your location, you may have
only 10-20 minutes to prepare for this event, so always stay
alert.
With the recent advancements in weather and personal
technology, we can now spend hours analyzing a plethora of
weather data. We can scroll through any number of short
and long term weather forecasts and pull out the
information that matters most to us. But despite all of this,
there is still great value to be found in putting that phone
back in your pocket, and just looking up.
Ron Bianchi is a senior meteorologist and the current
Director of Strategic Development for the Met–Ocean group
at Amec Foster Wheeler. He has held the position of VP of
Meteorology for the Weather Network/MeteoMedia, and
served as Operations Manager for Environment Canada’s
Storm Prediction Centre in Ontario. He is Past President of
the Canadian Meteorological and Oceanographic Society,
and a Fellow of the Royal Meteorological Society and
American Meteorological Society.
14 TOP: Squall Line formation, BELOW: Thunder Head
A CYA Sailing and Power Instructor from 1982 to 2000,
Ron has managed and taught sailing, meteorology,
navigation, and boat safety for several sailing schools
throughout the GTA.
He has also developed a process to model high-resolution
winds over most locations in Canada, and has taken that
development to the sailing community, helping various
regattas by providing very detailed hourly wind forecasts for
any race course.
HELPFUL WEATHER APPS
STORM
Storm for iPhone and iPad is the most advanced
severe weather app available, bringing you the
highest definition radar, advanced storm tracking,
and real-time severe weather alerts.
https://www.wunderground.com/micro/storm/
INTELLICAST WEATHER
https://play.google.com/store/apps/
details?id=com.wsi.android.intellicast&hl=en
PREDICTWIND APP
https://www.predictwind.com/apps/
BOAT SHOW 2017
Say you saw it in GAM