Heads Up To The East Coast

This posting was made Tuesday, September 27, 2013. Forecasts change. This one has radically since it was published. – Geoff

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Last year, when Hurricane Sandy was a little pipsqueak south of Cuba, I noted how the European computer model was developing a storm unlike any I’d seen before. Its path took it toward the New York/New Jersey metro area, then Southern New England, moving toward land from the east.

The Euro was right. Sandy struck.

That’s why I’m a little uneasy about the last two Euro runs. Both bring a storm up a similar path.

Make no mistake, it’s very early. These two runs disagree on exactly where this storm will go, but they’re reasonably close. All the areas affected by Sandy are threatened again, probably late this weekend into early next week.

I can’t emphasize too strongly, computer modeling is notoriously suspect this far out. Beyond that, models like the European are made for synoptic scale weather–larger systems. Tropical cyclones are too small to be handled properly.

However, you can’t dismiss the Euro’s uncanny accuracy last year in a very similar situation.

There’s probably nothing you can or should do right now, except think about what you will do should this threat persist. If you’re in one of the affected areas, you’re already battle hardened.

Hurricanes and tropical storms seem romantic in the abstract. It only takes a day or two without the necessities of 21st Century life to bring you back to reality.

I hope the Euro is wrong.

During Hurricane Season I’m 24/7

Gulf storms NEVER come to New England while still a named storms. We can and do get their rainy remnants often.

Florence is more a Connecticut concern… though not very much right now. She is very far out in the Atlantic. Current predictions bring Florence to a position where it could threaten the East Coast.

I went to Sergio’s tonight to pick up dinner. Rena was there. Her dad was too, back in the kitchen. He lives part time in Connecticut and part time in Florida.

“I’ll try and keep Ernesto away from Florida,” I said, as if I had any influence.

Another customer waiting to pick up his order gave me a supportive look. Maybe I’m reading too much into this, but he liked the fact I was up on my tropical weather even though I was wearing jeans and an already shrunken too small Alaska t-shirt.

When I first started in weather it was tough to know what was going on unless you were at work. I didn’t have access to the pre-www Internet until the late 80s.

Nowadays, if I could convince my boss to put a camera here in the house, I could do the weather from here! I have access to a fire hose of weather data. In fact the biggest problem I have is deciding where and in what form I’ll get my data.

Bottom line is during hurricane season everyone expects me to be up-to-date 24/7. I don’t blame them.

It’s still early in the hurricane season. We are already ahead of schedule with storms. The “E” storm historically doesn’t get here until August 31!

There are different concerns with Ernesto and Florence.

Ernesto could move into the Gulf if it doesn’t lose too much strength when it hits the Yucatan. There are lots of sparsely populated places on the Gulf and the Yucatan. That’s the hope.

Gulf storms NEVER come to New England while still a named storms. We can and do get their rainy remnants often, not their wind.

Florence is more a Connecticut concern… though not very much right now. She is very far out in the Atlantic. Current predictions bring Florence to a position where it could threaten the East Coast. It’s way too early to worry.

Like I said I’m 24/7 during the hurricane season. I’ll write more on “E” and “F” as warranted.

Everybody’s Curious About Invest 97

Of course they can also hit Florida or the Gulf or even Southern New England

There’s been a lot of chatter about Invest 97, the pre-tropical storm still pretty far out in the Atlantic. Right now the system hardly exists! In fact the map I chose to show (above) is a forecast map because you can’t find it on the latest observed analysis!

In spite of this people are petrified. This storm is certainly worth watching. It has to do with climatology.

Tropical systems more than any other I talk about are seasonally affected. Certain times of the season certain specific tropical basins are ‘open for business.’ Storms that form within those zones also have a moderately favored trajectory. It too changes with the season.

Most of the storms that form where Invest 97 is located head northward up the East Coast. Cape Hatteras is a favorite target. Of course they can also hit Florida or the Gulf or even Southern New England&#185. Any threat is still at least a week away.

This is not a weather prediction. Only a fool would predict a tropical system this far out. This is just an examination of what similar storms have done in the past. It should concern a lot of people.

Click for a more detailed mathematical explanation.

&#185 – Approximately 1% chance of a Southern New England hit by this storm with hurricane force winds.

The 360 Hour From Now Hurricane That Won’t Happen

Here’s the good news. 360 hours out, especially in the summer, we have almost no skill at all!

Have you seen the 360 hour forecast from the 18z GFS? Don’t worry. I looked for you!

The GFS (Global Forecast System) is a dynamic atmospheric computer model. It’s one tool in forecasting the weather.

The +360h iteration (valid August 25, 2011 at 1:00 PM) puts some sort of hurricanish storm just south of Long Island. Ominous is a good word to describe what the map portrays.

Here’s the good news. 360 hours out, especially in the summer, we have almost no skill at all! Saying its late August is probably a more convincing argument for a nearby hurricane than anything the GFS outputs.

Every time I see one of these systems (nearly guaranteed not to be on the next model run) I ask myself the same thing: Why even bother going out that far?

I don’t think there’s a good answer.

Why Earl’s On My Mind

Forget the hurricane. It’s no threat. Keep your eye on the Tropical Storm–Tropical Storm Earl.

There’s a Category 4 Hurricane and a Tropical Storm both in the Atlantic right now. Forget the hurricane. It’s no threat. Keep your eye on the Tropical Storm–Tropical Storm Earl.

It’s likely Earl will graduate this weekend and become Hurricane Earl.

I’m not going to try and fool you. Most likely Earl is headed toward the fishes. Most Atlantic tropical systems miss land entirely! Not all of them.

There’s a huge downside to being wrong so I try and stay current with the situation.

I’ve attached the scariest computer output I could find. It’s the GFS model and that’s Earl off Cape Hatteras next Friday afternoon at 2:00 PM. It quickly gets less menacing catching a more easterly flow and turning northeastward farther into the ocean.

The projection is from a model not designed to work with tropical systems. Out 180 hours even small errors will multiply. It’s the best we’ve got.

Don’t worry. If Earl decides to become a factor in our lives I won’t hold back.

The Hurricane Forecast Arrives

That’s not to say I still don’t worry about a hurricane hitting the Northeast as happened tragically in 1938. I do. I worry a lot.

The Colorado State hurricane forecasters have issued their annual tropical weather call.

We continue to foresee above-average activity for the 2010 Atlantic hurricane season. We have increased our seasonal forecast from the mid-point of our initial early December prediction due to a combination of anomalous warming of Atlantic tropical sea surface temperatures and a more confident view that the current El Niño will weaken. We anticipate an above-average probability of United States and Caribbean major hurricane landfall.

What does this mean? Virtually nothing… and I’m not even going to take the cheap shot of mentioning this hurricane forecast comes from the very non-tropical and landlocked state of Colorado!

Unless you are an insurance underwriter or maybe someone selling building supplies hurricanes are anecdotal events. Individual places see hurricanes so infrequently that the difference between it being a 1% or 1.4% chance is meaningless. It’s like considering the odds you’ll get a straight flush every time you’re dealt a poker hand. It can happen, but it mostly won’t.

Even when judged by a broader view these studious projections have shown less than stellar accuracy lately. The same goes with forecasts from ‘for-hire’ forecasters. That’s not to say I still don’t worry about a hurricane hitting the Northeast as happened tragically in 1938. I do. I worry a lot.

In spite of the axiom, lightning and hurricanes often strike twice.