We Actually Managed To Get Tropical Storm Arlene Out In The Atlantic

The swirls clouds in the center of this satellite photo of a
lot of clouds in the North Atlantic is Tropical Storm Arlene,
which was expected to get absorbed into the rest of the
clouds and dissipate later Friday. 

The other day, I told you about a subtropical storm trying to get going way out in the Atlantic Ocean.

It did, and did something I told you was highly unlikely: It turned into a pure tropical storm.

Yep, Tropical Storm Arlene was spinning way out in the Atlantic Ocean early Friday morning, way northwest of the Azores and way northeast of Bermuda.  It had sustained winds of 50 mph.

It joins Ana in 2003 as the only tropical storms known to have formed in the Atlantic in April.

Arlene is also the furthest north a tropical storm was found in the Atlantic this early in the season.

That doesn't mean it never happened before. Arlene was a tiny little thing embedded in a big area of storminess in the North Atlantic.

Before, say, 1970, when satellites really started taking pictures of the Earth's clouds from above, little tropical storms like this would almost surely have gone undetected.

Who knows? There might have been many April tropical storms that we never knew about.

Subtropical storms, as I mentioned the other day, are hybrids between storms with warm cores, and regular storms, that have cold upper level cores along with cold and warm fronts.

Arlene managed to transition to a warm core storm, but a lame one.

That's because it's core is indeed warmer than its surroundings, but its surroundings are cold. Water temperatures beneath Arlene are a little under 70 degrees. Usually you need water temperatures several degrees warmer than that at least to sustain a tropical storm. '

In any event, Arlene will get sucked up into the other storminess around it today and cease to exist. It poses no threat to any land areas.

Rare April Subtropical Storm Might Be Forming In Atlantic Ocean

A rare - for this time of year anyway - subtropical storm might be forming way out over the Atlantic Ocean today. 

This swirl of clouds way out over the Atlantic Ocean
could become a subtropical storm today. If it does,
it would be named Arlene.

Subtropical storms are hybrids between pure tropical storms and hurricanes, which have warm cores.

Most other kinds of storms have cold air at their cores, and have cold and warm fronts attached to them. 

Subtropical storms have elements of regular storms, such as a cold pocket of air within them. 

However, like tropical storms, subtropical storms have no cold or warm fronts, and thunderstorms spinning around an often cloud-free center. 

Subtropical storms are given names, just like tropical storms, and would show up on a list of any year's tropical storms or hurricanes if they form. 

Tropical or subtropical storms in the Atlantic Ocean are very rare in April, when ocean tempeatures tend to be coolest. Most of these storms need warm water to survive. 

The last time there was an Atlantic subtropical storm was Ana in 1993.

The possible subtropical storm now is forming way out there in an expanse of ocean between Bermuda and the Azores. The National Hurricane Center gives it a 70 percent chance of becoming a subtropical storm. 

If it does form, it will be named Arlene. 

Deciding whether a storm like this one is subtropical or not is pretty subjective. I've seen some pretty spirited arguments on Twitter today from weather geeks as to whether this one qualifies or not. 

If it's decided a subtropical storm forms today, it won't last long. Forecasters expect it to be swallowed up by a larger regular storm on Thursday. 

Subtropical storms can grow and change into purely tropical storms, with totally warm cores and no cold air anywhere near them. 

The only time this has been known to happen was with the already-mentioned Ana in 1993. 

If a subtropical storm forms today, it is very unlikely to become purely tropical.