Teachable Moments: Get used to ’em.

Washington Monthly:

You might ask yourself, aren’t hurricanes supposed to weaken as they head north? Why are these pressures so low? Or as the Weather Channel’s Bryan Norcross put it: “What the hell is going on?”

Norcross’ answer: “This is a beyond-strange situation. It’s unprecedented and bizarre.”

These historic low pressure levels simulated by the model are equivalent to a category 3 or 4 hurricane, which have peak winds over 115 mph. But Sandy’s winds will not be that high, because as it transitions into this hybrid hurricane-nor’easter, its core will unwind. So its peak winds will diminish, but strong winds will be felt over a vast area. Think of a compressed slinky expanding as you let it go.

WJLA meteorologist Ryan Miller notes 66,549,869 people live in the National Hurricane Center’s track zone for Sandy. A large percentage of these people will likely contend with tropical storm force winds – 40-60 mph, if not somewhat greater….

A very prominent and respected National Weather Service meteorologist wrote on Facebook last night,

I’ve never seen anything like this and I’m at a loss for expletives to describe what this storm could do.

Bloomberg:

Sandy may combine with a second storm coming out of the Midwest to create a system that would rival the New Englandhurricane of 1938 in intensity, said Paul Kocin, a National Weather Service meteorologist in College Park, Maryland. The hurricane currently passing the Bahamas has killed 21 people across the Caribbean, the Associated Press reported, citing local officials.

“What we’re seeing in some of our models is a storm at an intensity that we have not seen in this part of the country in the past century,” Kocin said in a telephone interview yesterday. “We’re not trying to hype it, this is what we’re seeing in some of our models. It may come in weaker.”

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Sandy’s apparent weakening doesn’t accurately predict the storm it may become, said Matt Rogers, president of Commodity Weather Group LLC in Bethesda, Maryland. Computer models suggest the hurricane may transform into a hybrid system over the weekend because of another storm moving in from the Midwest.

“When the storm phases with the energy from the west, it is forecast to deepen rapidly,” Rogers said. “Indeed, it is expected to continue weakening until phasing really takes place late Sunday into early Monday.”

The 1938 hurricane killed more than 500 people after crossing Long Island and battering Connecticut and Rhode Island.

“We can say even now our worst fears may be realized,” Kocin said. “If we were seeing what we’re seeing today one day out, we would really be shouting the alarms.”

Key takeaways on the eve of this significant storm:

Climate Change is changing the weather. The last several years have been marked by a series of extreme weather events that fit the characteristics of a changing climate

A warmer atmosphere provides more energy for storms

A warmer atmosphere holds more water, and that can make storms more destructive

Storm surges are now riding on top of elevated sea levels, amplifying flooding along coastal areas

Right now, Sea surface temps along the Northeast US coast are about 5 F above average, which is likely to keep the  storm powered up and load extra moisture, fueling heavy rains. September had the second highest global sea surface temps on record

In the Northeast US, sea levels are rising up to 4 x faster than the global average, making this area more vulnerable now, and in the future

Multiple high tides may help drive flooding fueled by a triple climate-whammy: storm surge from a storm kept alive due to elevated SSTs, sea level rise driven by global warming, and extra heavy rains due to the additional available moisture