The calm before the storm

I’m starting to realize just how stressful it is, being hypervigilant. This morning, they’re saying the models are starting to indicate Sandy will be coming ashore in the vicinity of the Delmarva peninsula (where I live) and along the I-95 corridor (I live a few blocks from I-95), just as the “longshot” European model has said all along. They also make a point of saying it doesn’t much matter where the storm makes landfall, it’s still going to have a massive impact. Still thinking about storm surge and flooding ALL. THE. TIME. It would be hard not to, when NOAA is predicting coastal waves of 15-36 feet. (Thanks, petroleum lobbyists!)

The thing is, it’s also really dangerous to travel when there’s so much flooding. So I’m probably going to stay put until the storm passes, and then if the power’s out, I’ll go stay with friends.

Sandy was downgraded to a tropical storm last night, but NOAA is reporting hurricane-force winds again this morning. They’ve said all along not to be fooled by a downgrade, that the closer it gets, the more powerful it will become as it passes over the abnormally warm Atlantic ocean.

With a major storm headed my way really my neuroses are in full bloom!

The Mid-Atlantic and Northeast coasts should be prepared for a storm surge no matter their exact location. A large portion of the coast will feel the impact of up to 60 mph winds and heavy rain. According to the most recent H*Wind analysis from the Hurricane Research Division is that storm surge has a destructive potential of 4.8 out of 6.0, which is a slight increase from previous analyses. Wind damage potential is holding steady around 2.3 out of 6.0. NOAA’s HPC is forecasting rainfall totals of 5 to 10 inches in the Mid-Atlantic and Northeast, and possibly more in coastal locations close to the core of the storm. Widespread power outages from Maine south to Virginia are likely, due to the combination of long-lived gale-force winds, leaves on trees, and rain that will moisten the soil and possibly increase the chances of falling trees. Snow in the Appalachians is also possible as the intense moisture meets the cold air being pulled south by the mid-latitude trough.

During September 2012, ocean temperatures off the mid-Atlantic coast in the 5×10° latitude-longitude box between 35 – 40°N, 65 – 75° W were 2.3°F (1.3°C) above average, according to the UK Met Office. This is the 2nd greatest departure from average for ocean temperatures in this region since reliable ocean temperature measurements began over a century ago (all-time record: 2.0°C above average in September 1947.) These unusually warm waters have persisted into October, and will enable Sandy to pull more energy from the ocean than a typical October hurricane. The warm waters will also help increase Sandy’s rains, since more water vapor will evaporate into the air from a warm ocean. I expect Sandy will dump the heaviest October rains on record over a large swath of the mid-Atlantic and New England.

Hurricanes are expected to dump 20% more rain in their cores by the year 2100, according to modeling studies (Knutson et al., 2010). This occurs since a warmer atmosphere holds more water vapor, which can then condense into heavier rains. Furthermore, the condensation process releases heat energy (latent heat), which invigorates the storm, making its updrafts stronger and creating even more rain. We may already be seeing an increase in rainfall from hurricanes due to a warmer atmosphere. A 2010 study by Kunkel et al. “Recent increases in U.S. heavy precipitation associated with tropical cyclones”, found that although there is no evidence for a long-term increase in North American mainland land-falling tropical cyclones (which include both hurricanes and tropical storms), the number of heavy precipitation events, defined as 1-in-5-year events, more than doubled between 1994 – 2008, compared to the long-term average from 1895 – 2008. As I discussed in a 2011 post “Tropical Storm Lee’s flood in Binghamton: was global warming the final straw?”, an increase in heavy precipitation events in the 21st Century due to climate change is going to be a big problem for a flood control system designed for the 20th Century’s climate.

For those of you have never lived in hurricane country, the approach of a major storm is always accompanied by several days of ominious overcast skies, the outer cloud band that covers hundreds of miles. We haven’t seen much of the sun for the past week.

Today I need to get my plants and patio furniture out of the way, and get my cooler out of the garage, since it would be nice to have some real food through this ordeal.