Wednesday, September 30, 2015

With Or Without Joaquin, East Coast In For A Flood

Visible satellite view of Hurricane Joaquin this morning
It could threaten the increasingly soggy East Coast Monday. 
The first round of torrential downpours is crossing the Northeast,  having trekked from the Gulf Coast through the Mid-Atlantic States and on into New England.

Flood alerts are up. This is the first wave of what promises to be several waves of dangerous downpours for much of the eastern United States. Beware, this could be scary in spots.

Yesterday, I said that things were totally uncertain and there was a mix of hype and genuine forecasting concern out there.

That's still true today, but things are a little more in focus now. Still, expect big changes in the forecasts in the coming days, with various areas coming under threat from floods at different times.

Hurricane Joaquin is going to enter the picture. We don't know exactly what effect he'll have on this mess. But whether or not the hurricane ultimately comes ashore on the East Coast or stays well off the coast, there's still going to be a bunch of rain. And I mean a BUNCH!

These flooding threats over the next week or so are going to hit some of the most populated areas of the nation. I wouldn't be surprised, if some of the forecasting models are right, that this has the potential to be a billion dollar disaster, given the huge area of the country under threat from the downpours.

I don't think I've ever seen computer models forecast seven or more inches of rain over several days in one, 1,000 mile stretch of the nation. But I've seen it this time.


The first wave of rain caused flooding Monday in the Mobile, Alabama area and in the Florida Panhandle. Tuesday, parts of the mid-Atlantic states were targeted, especially western Virginia.

Today, the focus of heavy rain is across New England and eastern New York. More than four inches of rain might fall in some areas, especially Maine, parts of New Hampshire, the southern half of Vermont and northern Massachusetts.

Already, Burlington, Vermont had had a storm total of 2.78 inches as of 8 a.m. Wednesday,  It was still raining steadily there.

Even though New England had a dry September up until now, there is a real threat of flooding today.  Nothing like Hurricane Irene in 2011, for sure, but still something to be careful about. Already, flood warnings were flying for much of western New Hampshire and southwestern Maine as of 8 a.m.


The focus then shift south of the Mid Atlantic states, possibly as far north as southern New England as a stalled front, tropical moisture moving north and a strong high pressure system from the north feeds in gusty Atlantic air from the east.

The potential for heavy rain over the next couple of days, into Saturday have little to do with Joaquin, which will still be drifting vaguely toward the United States, but still east of the Bahamas.

The U.S. rains later this week and into the weekend are called a "predecessor" storm. Often along the East Coast, before a hurricane, the weather pattern features fronts and moisture that slam certain areas with flooding rains.

The devil is in the details here, as we don't know where the focus of heaviest rain will be, but somewhere between North Carolina and Maryland, at least half a foot of rain could come down between Thursday and Saturday. A few computer models forecast a FOOT of rain.

This would lead to flooding, obviously, since it's already rained hard there the past couple days. If things come together just right, the flooding could be particularly severe and disastrous in some areas.

Again, stay tuned.


Formerly weak Tropical Storm Joaquin strengthened robustly overnight and as of 8 a.m. was a Category 1 hurricane with top sustained winds of 75 mph.  .

During El Nino years, which we have now, strong upper level winds tend to rip apart nascent tropical storms in the Atlantic and we've seen that over and over this year. 
Various computer models are a little more focused
on Joaquin's future track than yesterday. Many
bring the hurricane into the U.S. East Coast
but there's still no guarantee that will happen.

This time, the upper level winds are relaxing in a small part of the Atlantic. The part where Joaquin is. So it can strengthen.

Also, in general, the warmer the water, the better chance a tropical storm has of strengthening.

Water temperatures are at record high levels east of the Bahamas, which again happens to be right where Joaquin is hanging out.

Joaquin is taking full advantage of that and it will almost surely strengthen today. 

The next question is, What's Joaquin up to after drifting slowly on vacation slowly westward or southwestward east  of the Bahamas the next few days.

Well, eventually, the stalled front and big trough of low pressure causing all those flood problems on the East Coast will pick it up and fling Joaquin northward.

But exactly where? Things are a little more clear with Joaquin's path than yesterday, but they're still very uncertain. Joaquin could move northeastward, off the coast. That would fling some moisture back into the already wet East Coast storminess and make the flooding that much worse, but it wouldn't be a worst case scenario.

Other computer models take Joaquin and have it come ashore, maybe Monday somewhere in the Carolinas or Mid-Atlantic Coast. That would be a HUGE disaster, given the wind, the storm surge and especially the inland flooding that result in the Mid-Atlantic and Northeast.

As a side note, you might remember that in 2012, the European computer model, well in advance, told us Superstorm Sandy would hit the U.S. East Coast while the other models said it would miss.

Well, the European model was famously right and warned us well in advance.

This time, the European takes Joaquin far out to sea while many of the other forecasting models have the  hurricane hitting the coast.

Just because the European model was right with Sandy doesn't mean it will be right with Joaquin. Residents should still start preparing for a possible hurricane. But it will be interesting to see what happens.

The idea of Joaquin coming ashore is a scary scenario, but we just don't know if it's going to happen yet. Keep an eye on it. You'll see updates everywhere, including in this blog thingy.

Meanwhile, if you're anywhere in the eastern United States, keep an ear to forecasts. If there's any kind of flood warning, do what they advise. If they say evacuate now, do it. Now.

Every time there's a flood, people also drive onto flooded roads and get stuck. Or worse, washed away. I have no idea why people ignore the "Turn Around, Don't Drown slogan.

Please, don't be an idiot.

And we'll keep an eye on this weather event, which is pretty wild, if you ask me.

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