Caribbean Dust, And New England The New Miami-Dade

Same two views on the island of St Barthelemy, before
the dust, top, and during the current outbreak of
Sarahan dust.  Photos by Mirco Ferro, via Twitter

We've got a this n' that post for you today, as the weather always fascinates.  Or at least gets weird pretty often.

So let's get started

SAHARA DUST

Time to head to a nice Caribbean island to enjoy the dust storms.

Wait, what?

I'm exaggerating when I'm calling the current weather in the tropical Atlantic a dust storm, but it is pretty damn dusty down there.

A huge plume of dust from the Sahara Desert in Africa has blown westward and is crossing the Atlantic Ocean.

Visibility on some islands was down to three miles or so, a sharp contrast to the deep blue skies and long views that residents and vacationers are accustomed to.

The dust will reach the U.S. Gulf Coast this week, causing hazy skies, beautiful sunrises and sunsets and maybe suppressing thunderstorms.

This cloud of dust from the Sahara desert actually isn't all that weird. These plumes of dust cross the Atlantic frequently from late spring to early fall.  This episode is just more intense than usual. Some observers are saying this plume is the thickest in five decades.

In one important respect, the dust clouds are a good thing, even if it does reduce visibility and hurt people with pre-existing respiratory problems.

The dust clouds suppress the thunderstorms needed to give birth to tropical storms and hurricanes. Such dangerous storms are much less likely when there is a plume of Sahara dust over the Atlantic.

It's early in the hurricane season now, so there probably wouldn't have been any tropical storms anyway this week, but if more dust clouds form and move out over the Atlantic, there's a chance it could reduce what is expected to be a busy hurricane season.

Don't count on that, though. Just because there's a big cloud of dust now doesn't mean it will keep happening with the same intensity all summer. and fall.  This just happens to be a random big outburst.

FLORIDA MOVES NORTH

Tropical style thunderstorm erupting Satiurday in Florida  oops
I mean Vermont. Things are a bit topsy turvy

The weather in New England has consistently been just like what you'd expect in Florida during the summer the past few days.

Heat waves hit New England almost every summer, of course. But this one has taken on the characteristics of a Florida summer.

In the Deep South, there are typically few major weather systems coming through in the summer. Cold fronts from Canada don't make it that far south, and no big storm systems come across the country to stir up the weather.  

Which means local conditions rule the roost when it comes to the weather.

In Florida's hot, humid weather sea breezes push inland, and form little weather fronts separating the marine air from the hotter conditions over land. These little weather fronts create just enough lift for daily thunderstorms in Florida during the summer.

Meanwhile, local updrafts  create more thunderstorms over interiror Florida.

Up here in New England, we're usually far enough north so that the usual roughly west to east flow of weather systems continues.  A cold front will come through with a burst of thunderstorms, followed by coolish, dry sunny weather, then a bout of hot, humid conditions, followed by another cold front, rinse and repeat.

You know the drill.

The past several days, and today, are featuring a pattern much more like Florida. There's no weather systems moving through, just a dome of hot, humid air over New England and southeastern Canada.

Which means New England is temporarily the new Miami-Dade. One of those sea breeze fronts created scattered thunderstorms a little inland from the coast in Massachusetts yesterday.

Meanwhile, local updrafts continued the daily rounds of scattered storms in interior New England. Unlike Florida, we have mountains, which are more than enough to create the initial updrafts to create those slow moving thundersetorms. They pop up, dump a big downpour on a small area, then dissipate. Then a few more form and do the same thing until the sun sets.

We'll finally revert back to typical northern weather patterns starting Tuesday.  The west to east flow of systems will resume.  A couple weak cold fronts will come through, creating a better chance of showers and storms later Tuesday and Wednesday.

The heat will then diminish, at least for awhile, starting at the end of the week.

Speaking of heat, Burlington has a shot of tying the record for the most 90 degree days in the month of June. The record is seven, set in 1949.

We've had five such days this June, and we are on track to tie the 1949 record. High temperatures in Burlington are expected to reach 90 degrees today and tomorrow.