Are the Tropics Cooking up an October Surprise? Don’t Look now, but Something’s Gaining on us…

October 24, 2012

Weather Underground:

The majority of the possible tracks now head into the Northeast, New England, or Atlantic Canada.

Could it really be a strong hurricane, as the European model predicts? We know that, occasionally, hurricanes do occur at these high latitudes at the end of October. Famously, the “Perfect Storm”, otherwise known as the Halloween Hurricane battered New England in 1991. Also, Category 2 Hurricane Ginny hit Nova Scotia in late October 1963. But, neither were of a scale and impact like the Euro is showing.

With the influence of the jet stream, you would think any storm that comes ashore would be subtropical in nature – part tropical and part like a nor’easter – but the NHC doesn’t allow for subtropical hurricanes in their naming scheme. It’s considered to be such a rare and nearly impossible event.

The spectacularly unusual confluence of events is the shape and orientation of the dip in the jet stream that is forecast to develop over eastern North America over the weekend – oriented in such a way to pull Sandy inland instead of pushing it out to sea, and the presence of a strong tropical or subtropical system where it can get pulled in. That’s so bizarrely unusual that I can’t think of another event like it.

This kind of thing occasionally happens with nor’easters, notably the Great Appalachian Storm of November 1950 which curved in off the Atlantic and dumped 20 to 30 inches of snow over a wide area in the Mid-Atlantic and Midwest, but the odds of it happening with a system that originated in the tropics – with all of the moisture that that implies – are extremely low.

A knowledgeable correspondent adds more:

Models are split on whether Sandy will hit New England (and New York City) Sunday night – Monday timeframe, but many of the more reliable weather models, including ECMWF & NOGAPS,  continue to hook Sandy inland early next week, sucked up in a larger-scale trough approaching the east coast.

Yesterday the NHC GFDL was sweeping Sandy out to sea, now it looks like a much closer track to the east coast. Only GFS whisks Sandy out into the Atlantic.

No idea how this might impact the election, but expect a fair amount of finger-pointing if there’s major damage from the Carolinas and Mid Atlantic coast to New England.

Models are hinting at a Category 3 storm or stronger. This brings back memories of “Grace” in 1991, which helped to fuel “The Perfect Storm” over New England.

This could get very interesting, a potentially unpleasant October Surprise

UPDATE from Jeff Masters at Weather Underground:

Sandy: a potential billion-dollar storm for the mid-Atlantic and New England
On Friday, a very complicated meteorological situation unfolds, as Sandy interacts with a trough of low pressure approaching the U.S. East Coast and trough of low pressure over the Central Atlantic. The Central Atlantic trough may be strong enough to pull Sandy northeastwards, out to sea, as predicted by the official NHC forecast, and the 06Z GFS, 00Z UKMET, 00Z Canadian, and 06Z HWRF models (00Z is 8 pm EDT, and 06Z is 2 am EDT.) However, an alternative solution, shown by the 00Z ECMWF, 06Z GFDL, and 06Z NOGAPS models, is for Sandy to get caught up by the trough approaching the Eastern U.S., which will inject a large amount of energy into Sandy, converting it to a powerful subtropical storm that hits the mid-Atlantic or New England early next week with a central pressure below 960 mb and sustained winds of 60 – 70 mph. Such a storm would likely cause massive power outages and over a billion dollars in damage, as trees still in leaf take out power grids, and heavy rains and coastal storm surges create damaging flooding. The full moon is on Monday, which means astronomical tides will be at their peak for the month, increasing potential storm surge flooding. A similar meteorological situation occurred in October 1991, when Hurricane Grace became absorbed by a Nor’easter, becoming the so-called “Perfect Storm” that killed 13 people and did over $200 million in damage in the Northeast U.S.


10 Responses to “Are the Tropics Cooking up an October Surprise? Don’t Look now, but Something’s Gaining on us…”

  1. rayduray Says:

    Re-insurer Munich RE has been a leader in comprehensive analysis of natural disasters for over 40 years. They’ve just issued a new 275 page report on natural hazards, including those as a result of climate weirding. I feel like the blind man feeling the elephant here. I’ve got the press release and a YouTube video intro to the new study. But the URL for the study remains elusive. Do any of you have it to share?



    Severe weather in North America

  2. rayduray Says:

    New blog post by Dr. Jeff Masters at WU on TS Sandy:

    At about 2 minutes into this weather video you can see how the models are starting to turn TS Sandy up into the NYC area on Saturday:

  3. rayduray Says:

    Another view toward a major storm in development.

    The latest is that the eye south of Jamaica is now at 974 Mb. Read below for the significance of this number….

    Here’s a fascinating article incorporating discussion of blocking patterns in the jet stream which we’ve discussed before quite possibly recurving Hurricane Sandy into the U.S. Mid-Atlantic Coast and spreading retrograde back to the Great Lakes region early next week. Talk about an October Surprise.

    Quoting meteorologist Marc Weinberg:

    “If all these events fall into place, we could be talking about a monster Superstorm in the northeast with flooding rains, major coastal flooding, significant beach errosion, and widespread power outages in the northeast. When you consider “The Perfect Storm” was 972 mb and the EURO shows this storm as a 944 mb low, you get the idea of the potential here. Remember “The Perfect Storm” produced 100 foot waves in the open sea and the EURO suggests this will be considerably stronger!”

    Ray again. Sandy has just been declared a Class 1 Hurricane. Winds are approaching 80 MPH and strengthening.

    • greenman3610 Says:

      thanks. Let’s track this, but not get too crazy just yet. One has to say the odds are still pretty long for this to become a threat to the East coast.

      • rayduray Says:


        Re: “One has to say the odds are still pretty long for this to become a threat to the East coast.”

        I’m highly confident that Hurricane Sandy is going to be epic. This is one of those rare instances that I would ever tender a bet on that particular outcome. 🙂

  4. guylacrosse Says:

    I wonder how this going to effect the voter turn out in the NE states.

    • ahaveland Says:

      We can but secretly hope that it knocks loudly enough on the doors of Congress without casualties to elicit an acknowledgement, but the now institutionalised Republican denial has almost become a clinically terminal phenomenon.

      This year’s massive and costly extremes didn’t nag any consciences, so I don’t really expect anything else than Business As Usual.

      I heard that it isn’t just about money for Republicans, it’s *only* about money. However, if that really were true, then why aren’t they paying more attention to insurance premiums? The survival of insurance companies depend on accurate risk assessments, so premiums should have the loudest voice of all to a smart Ferengi…

  5. […] Are the Tropics Cooking up an October Surprise? Don’t Look now, but Something’s Gaining … ( […]

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