Harvey’s toll continues

Weather forecasting is a challenge of science and a stimulating process for many of us as meteorologists. Many of us look at garden variety weather forecasts as sport. When it comes to Harvey, this isn't fun and games.

Harvey's meteorology is fascinating and unique. The human toll is already tragic. Harvey's economic shock waves will reverberate for weeks, if not months and years.

For now, we're still in life-saving mode. We're getting numerous 30 inch-plus rainfall totals recorded now, with isolated 40-inch totals northeast of Houston.

Houston has already set daily rainfall records. The record for wettest year on record is about to fall. In August.

Harvey coming up for air

Harvey is drifting slowly south today. As the center moves back over the still heat and moisture-laden Gulf of Mexico, Harvey will breathe in again. This will allow the storm to regain strength and enhance rainfall feeder bands on the storm's north and east sides.

The model consensus brings a stronger Harvey just offshore tomorrow, then turns the storm north once again. Right back toward Houston Wednesday.

Another 20 to 30 inches ahead?

I am hoping the overnight model runs are exaggerated. The National Oceanic and Atmospheric Administration's Global Forecast System model has been pretty good so far in estimating rainfall totals. The overnight 06Z run cranks out another 20 inches to near 30 inches close to Houston this week.

Worst flooding still ahead?

As water runs downstream toward Houston, any new rainfall on top of that may still produce the highest flood crests. Buffalo Bayou is already above record flood stage and forecast to rise another 11 feet in the next two days.

Bay City, Texas, is still expecting 10 feet of water downtown.

Massive Houston

The sheer size of this ongoing disaster is daunting. Houston, the nation's fourth largest city, is mostly underwater.

Katrina-level impacts?

Here's a great read from Weather Underground's Bob Henson on the likely economic impacts from Harvey.

The situation on the ground in Houston is gaining uncomfortable resonance with 2005’s catastrophic Hurricane Katrina. Instead of compromised levees, we have an extraordinary prolonged and intense rain event atop one of the nation’s largest and most flood-vulnerable cities.

As with Katrina, there have been numerous reports of people trapped in attics, and countless roads across the city are impassable. Given the unrelenting rains and flooding, there is real concern that some people will be unable to leave their homes or places of refuge for multiple days—a potentially life-threatening situation for those with special medical needs or without enough food and water.

It is too soon to tell exactly how many people are in such dire need, but the number of 911 calls and other cries for help suggest the number is far too large for comfort.

Harvey is sure to inflict a massive economic toll as well. Katina (2005, around $100 billion) and Sandy (2012, around $75 billion) were the nation’s two costliest hurricanes on record.

It’s easy to imagine Harvey rising into that range, although experts say it’s simply too soon to know for sure. Steven Bowen (Aon Benfield) told me: “We've got multiple days to go, and since we're already in uncharted territory for this type of flood event in Houston/Galveston, it's hard to fathom what might come next. There is no question that this is a catastrophic event that is going to have severe financial implications. The economic cost - from both direct damage and direct interruption impacts - is going to be well into the billions. We just don't quite know how many billions as of now. It's going to take weeks to fully take stock of the totality of the damage."  

Bowen points out that only 1/6 of Houston residents are insured through the National Flood Insurance Program, so thousands of people are likely to face devastating financial hits.

11 trillion gallons

How much water has fallen so far? Eleven trillion gallons.

Climate perspective

Here's an excellent read on climate links to Harvey.