Impact of the Atlantic warm pool on United States landfalling hurricanes

[bluewave]

http://www.aoml.noaa.gov/phod/highlights/research/load.php?pFullStory=20111101_20111201_Chunzai.html

In this study highlighted in the Editors' Choice of Science Magazine (issue of Oct. 21, 2011), NOAA scientists have identified a relationship between large–scale climate factors, the Atlantic warm pool, and hurricanes making landfall in the U.S. This relationship indicates that a large warm pool is an unfavorable condition for hurricanes to landfall on the United States coast.

http://www.aoml.noaa.gov/phod/docs/Wang_etal_2011.pdf

[gil888]

Wasn't 2005 a rather large warm pool year? The figure shown below is not very convincing...

[bluewave]

Wasn't 2005 a rather large warm pool year? The figure shown below is not very convincing...

Yes, they had a paragraph near the end of the paper on it.

[20] The factors controlling the TC track are complicated, determined by the TC internal dynamics and large‐scale climate as well as synoptic weather patterns. As an example, 2005 was a busy season and also had more landfalling hurricanes. Five of fifteen hurricanes in 2005 made landfall in the United States. Four hurricanes were formed in the MDR in 2005. Of these four hurricanes, one made landfall in Central America and the other three moved northward with- out landfalling in the United States. The AWP in 2005 was large although it was smaller than that in 2010 (Figure S8a). The SLP anomalies are negative in the AWP region, but near neutral over the U. S. (Figure S8d). The lack of SLP response over the U. S. may be due to different teleconnections induced by different AWP heating patterns or different latitudinal positions of the subtropical jet [Lee et al., 2009]. Associated with the SLP distributions are the steering flow anomalies showing the westward and northwestward flows in the trop- ical North Atlantic and the AWP region (Figure S8c), which were favorable for hurricanes to make landfall.

[icebreaker5221]

In summary:

"In this paper, we use the data from 1970–2009 to identify large AWP years by the top quartiles of the AWP index (1987, 1998, 2001, 2003, 2004, 2005, 2006, 2007, 2008, and 2009) and small AWP years by the bottom quartiles of the AWP index (1971, 1974, 1975, 1976, 1982, 1984, 1985, 1986, 1992, and 1994). These ten large and small AWP years are respectively associated with 31 and 13 hurricanes that form in the MDR, of which 7 and 5 hurricanes make landfall in the United States. This indicates that (1) the large AWP increases the number of hurricanes formed in the MDR, and (2) but the large AWP decreases the ratio of U. S. landfalling hurricanes by about 40%."

So, the part that I was looking for: years with anomalously warm MDRs still have more total hurricane landfalls than years with cool MDRs, just a lower percentage of the total.