2017 Hurricane season live blog – Harvey, Irma…




The 12-year-long US 'major hurricane' drought is over with the Texas Category 4 landfall of Hurricane Harvey. Hurricane Irma may become the second landfall in as many weeks.

'Major hurricanes' are category 3 and higher. The last major hurricane to make landfall in the US was Hurricane Wilma in Florida 2005. NASA's Dr Tim Hall has been following this year's storms for InsuranceLinked.

Dr Tim Hall Sep 9th, 20173:36 PM

Interaction with Cuba has weakened Irma to 110 kt sustained winds (NHC, 11am update). But it’s turning north toward Florida and the Florida straights are warm, so some re-intensification is forecast. After it crosses the Keys, the bulk of model tracks have it skirting up the west coast, making landfall somewhere between Naples and Tampa Bay late Sunday. But Irma is big; hurricane-force extend 70 miles out from the center.

Dr Tim Hall Sep 8th, 201712:35 PM

NASA Visible-Infraread Imaging Radiometer image from Thursday: Cat 1 Katia, Cat 5 Irma, and Cat 3 Jose, left to right. Read ’em and weep.

Dr Tim Hall Sep 8th, 20171:44 AM

Thoughts and prayers to the northern Leewards. Reeling from Irma’s devastation, in just 48 hours they may well get slammed by a second major hurricane, Jose.

Dr Tim Hall Sep 7th, 201710:10 AM

Massive damage on the tiny northern Leewards from cat-5 Irma’s direct passage yesterday. Irma’s NHC concensus track continues to have southern Florida in target for Sunday, though there is model spread, with ECMWF a bit further west and GFS brushing Florida’s east coast with possible first landfall on South Carolina. The storm weakened slightly overnight, though still cat 5. Cat-4 landfall near Miami a strong possibility. Surge would be huge, with 15 ft high water marks very possible for a high-tide landfall.

editor Sep 6th, 20174:42 PM

“It looks like it could be something that will be not good. Believe me, not good.” – you know who.

Dr Tim Hall Sep 6th, 20173:56 PM

Irma’s eye passed over Barbuda, St Barts, and St Martin this morning as a Cat 5. Irma is heading west northwest, but sometime around 3 days it will turn sharply north. The point at which that right-hand turn occurs strongly affects Florida. Since yesterday, the models indicate a slightly increased chance of it happening sooner, increasing the odds of the track passing just east of Florida and making first landfall on the Carolinas. Compare the GFS ensemble plot below from 600UTC Sep 6 to the one posted yesterday 1200UTC Sep 5. But direct Florida landfall is still a strong possibility.

editor Sep 6th, 201711:18 AM

The 2017 Citrus Re traded at 50.5 cents on the dollar yesterday according to Bloomberg. The sponsor is Floridian insurer Heritage. Shares in Heritage fell 16% yesterday – in line with other Florida focused insurers.


Dr Tim Hall Sep 5th, 20177:15 PM

Of the 20 members in the GFS’s 12:00-UTC ensemble Irma forecast shown below, 14 hit Florida (around day 5 or 6), another 5 make first landfall on the Carolinas. Only one misses (barely).

Dr Tim Hall Sep 5th, 20174:47 PM

Direct passage of Cat 5 hurricane over northern Leeward Islands (St. Martin, St, Barts, Antigua) in next 12 hours …

Dr Tim Hall Sep 5th, 20173:35 PM

At 155 kt sustained winds and 931 mb central pressure (11am eastern) Irma is now the most intense Atlantic hurricane ever reliably recorded outside the Caribbean/Gulf.

Dr Tim Hall Sep 5th, 20171:04 PM

Irma is now a Category-5 hurricane. Based on NOAA and USAF hurricane-hunter aircraft measurements of last several hours the NHC has raised the maximum sustained wind speed to 150kt. There’s no reason to expect significant weakening over next few days, as there’s plenty of ocean heat, moist air, and little wind shear in Irma’s path, barring significant time over Cuba.
Southern Florida is now in the NHC’s 5-day cone of uncertainty.

editor Sep 5th, 201711:25 AM

Wunderground blog looks at some of the potential long-term tracks for Irma.

Dr Tim Hall Sep 4th, 20171:11 PM

Irma is an increasingly good bet to hit the mainland US as a major hurricane. Irma’s five-day forecast has now shifted westward, before making a northward turn around the western edge of an expanding Atlantic high pressure system. Although the NHC’s cone of uncertainty does not yet reach the mainland US, it skirts across the northern edge of the Leeward Islands, Puerto Rico, Hispaniola, and eastern Cuba, and the various forecast models are tightly clustered at 5 days. Longer-range ensemble forecasts then have Irma turning northward, and in many cases plowing into southern Florida (see the figure below). Sea surface temperatures in front of Irma are anomalously warm and vertical wind shear is low. There’s no reason Irma can’t maintain its category 3 intensity or even strengthen. The NHC consensus forecast calls for slow strengthening over the next three days (though intensity forecast skill is notoriously low). After that, there is the possibility of some gradual weakening, if Irma passes directly over Caribbean islands.

Figure: Seven-day ensemble forecasts from the US NWS GFS initialized 2am Sep 4 US eastern. Purple indicates the inner 50% of ensemble members.

editor Sep 3rd, 20178:28 PM

Topical Storm Risk’s latest forecast out to September 8…

editor Sep 3rd, 20179:43 AM

RMS estimates economic losses from of $70 billion – $90 billion and National Flood Insurance Program losses of $7 billion – $10 billion. If NFIP losses exceed $8 billion then reinsurers will pick up $1 billion of the loss.

Dr Tim Hall Sep 3rd, 20178:05 AM

Harvey’s destruction will take months to tabulate. Some current numbers: 46 confirmed dead, 10,000s in shelters, many more without power or drinking water, standing floodwater water contaminated by sewage and industrial leakage, explosions at petrochemical plants, $8B-$12B in insured residential losses mostly flood (CoreLogic), $15B-$25B more in uninsured residential losses, and unknown multiples of that in total economic damage.

Meanwhile, Hurricane Irma is strengthening in central sub-tropical Atlantic and is forecast for Cat 4 intensity. Too early for any skill, but a significant fraction of ECMWF’s 15-day ensemble forecast have Irma making US landfall.

Dr Tim Hall Sep 3rd, 20178:05 AM

CoreLogic a leading global property information, analytics and data-enabled solutions provider, today announced preliminary residential loss estimates for Hurricane Harvey. According to the data analysis, insured flood loss for homes in the 70-county area in Texas and Louisiana affected by the storm is estimated to be between $6.5 billion and $9.5 billion, which includes inland, flash and storm surge flooding. An additional estimated $1 billion to $2 billion in insured loss is attributed to damage from wind. Residential uninsured flood loss for the same area is estimated to be between $18 billion and $27 billion. As a result, an estimated 70 percent of flood damage from Hurricane Harvey is not covered by any insurance.

Data Highlights:

· Insured flood
loss covered by the National Flood Insurance Program (NFIP) is estimated at $6
billion to $9 billion.

This includes inland, flash and storm surge

More than 98 percent of residential flood
insurance in the U.S. is provided through the NFIP.

· Insured
flood loss from private insurers is estimated at less than $0.5 billion.

· Uninsured
flood loss, which represents damage from storm surge and inland flooding not
covered by any insurance policies, is estimated at $18 billion to $27 billion.

· Insured
loss from wind damage is estimated at $1 billion to $2 billion.

Loss Estimates from Hurricane Harvey

CoreLogic Analysis

Flood Loss

Total Flood Loss

$25-37 B

Insured by NFIP

$6-9 B

Estimated Percent



Insured by Private Insurers

<$0.5 B


$18-27 B

Total Insured Flood Loss

$6.5-9.5 B

Total Uninsured Flood Loss

$18-27 B

Total Insured Loss Including Flood and Wind


Insured loss represents the amount insurers will pay to cover damage and loss.

This analysis includes residential homes, including contents, and does not include commercial, loss of business or other broader economic loss from the storm.

Dr Tim Hall Sep 3rd, 20178:01 AM

From August 29th 2017: Harvey is now one of the worst flood catastrophes in US history. After a record-setting 72 hours over land as a tropical storm, Harvey currently sits off the southeast Texas coast ready to make a third landfall overnight near the Texas-Louisiana boarder.

The NHC reports that Harvey has set the US record for total rainfall for a single tropical cyclone; at 3pm the Cedar Bayou station reported 52 inches four-day total, and other stations nearby are above 48 inches. Reservoirs have reached capacity, and a levee 40 miles southwest of Houston has been breached, forcing evacuations.

The Houston Convention Center is reaching its limit, with 9000 people camped there, long lines of evacuees waiting to enter and 1000s stranded. Heavy rains will continue intermittently for several more days over southwest Texas and Louisiana before Harvey moves north and inland.

Houston has now seen the bulk of its rain total, but rivers and tributaries continue to crest, and dams barely holding on will almost certainly be breached, either purposely by the Army Corps of Engineers, or otherwise.

Dr Tim Hall Sep 3rd, 20178:00 AM

From August 28th 2017: Wind speed does not begin to describe the horrors of this hurricane. Harvey is essentially a giant pump parked on the Texas coast extracting water from the Gulf and dumping it on Houston. The rainfall is astonishing and record breaking; 30+ inches in parts of Houston and 10+ inches more to come.

Harvey’s total rainfall on the Houston area will be roughly 1% of the entire annual rainfall on the US. The Washington Post’s Capital Weather Gang worked out some mind-bending volume equivalents for the 9 trillion gallons of rain to date: a cube of water two miles on a side; nine days of the Mississippi’s flow; the city limits of New Orleans at the bottom of a 128-foot lake.

Yes, water drains. But it’s had a hard time with that, because the coastal storm surge blocked inland drainage routes, highlighting the damaging interaction between coastal surge and inland rain. And when the inland water does drain, it’s doing it through Houston and environs.

Whatever the insured losses due to the 130 mph winds and the 2-6 ft of surge on coastal Texas (AIR and RMS early estimates range from $1 billion to $6 billion), they pale in comparison to the rain-driven flooding. Insured flood losses will be much higher (JPMorgan estimates $10B-$20B). And the total economic damage will be much higher still, since only 15-20% of properties in affected areas have flood insurance.

Dr Hall is a climate scientist at the NASA Goddard Institute for Space Studies in New York City. He specialises in hurricanes and their relationship to climate. He develops statistical hurricane and weather hazard models, and has worked as a consultant to RMS and reinsurance companies. Dr Hall can be reached at http://www.linkedin.com/pub/timothy-hall/a2/709/b27/.

Posted: Monday, September 4th, 2017