Buresh Blog: February averages... 2019 disasters... proposed new measure of hurricane strength

Buresh Blog: February averages... 2019 disasters... proposed new measure of hurricane strength

Jacksonville, Fl. — The first half of January was warm, the last half not so much but still averaged well above average by more than 6 degrees.

So it’s on to February (leap year so 29 days!). Averages at JIA:

1st: 43 / 66 degrees.... 29th: 47 / 71 degrees

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Rainfall: 3.19″

Sunrise / Sunset: 1st - 7:17am / 6:02pm.... 29th - 6:53am / 6:25pm - gain 47 min. of daylight(!)

NOAA has organized the 2019Significant Climate Anomalies & Events”. U.S. highlights included hurricane Dorian brushing the Florida & Carolina coasts after devastating the Northern & NW Bahamas.... lots of flooding across the middle of the country... & very warm Alaska.

(NOAA)

Global 2019 temps. compared to avg. (Jax warmer than avg.):

(NOAA)

Global 2019 precip. anomalies (blue is wet!) [Jax drier than avg.]:

(NOAA)

An interesting paper has been published by Dr. Phil Klotzbach - longtime tropical cyclone researcher - in the AMS (American Meteorological Society) online journal - * here *. In short, Dr. Klotzbach points out that surface pressure (how low) is a better predictor of hurricane damage vs. “maximum sustained winds”. I have a tendency to agree as wind speeds are often way over-estimated & sometimes under-estimated. The abstract:

“Atlantic hurricane seasons have a long history of causing significant financial impacts, with Harvey, Irma, Maria, Florence, and Michael combining to incur more than 345 billion USD in direct economic damage during 2017-2018. While Michael’s damage was primarily wind and storm surge-driven, Florence’s and Harvey’s damage was predominantly rainfall and inland flood-driven. Several revised scales have been proposed to replace the Saffir-Simpson Hurricane Wind Scale (SSHWS), which currently only categorizes the hurricane wind threat, while not explicitly handling the totality of storm impacts including storm surge and rainfall. However, most of these newly-proposed scales are not easily calculated in real-time, nor can they be reliably calculated historically. In particular, they depend on storm wind radii, which remain very uncertain. Herein, we analyze the relationship between normalized historical damage caused by continental United States (CONUS) landfalling hurricanes from 1900-2018 with both maximum sustained wind speed (Vmax) and minimum sea level pressure (MSLP). We show that MSLP is a more skillful predictor of normalized damage than Vmax, with a significantly higher rank correlation between normalized damage and MSLP (rrank= 0.77) than between normalized damage and Vmax (rrank= 0.66) for all CONUS landfalling hurricanes. MSLP has served as a much better predictor of hurricane damage in recent years than Vmax, with large hurricanes such as Ike (2008) and Sandy (2012) causing much more damage than anticipated from their SSHWS ranking. MSLP is also a more accurately-measured quantity than is Vmax, making it an ideal quantity for evaluating a hurricane’s potential damage.”

(Phil Klotzbach/Phil Klotzbach)