, °F

Personalized Forecasts

Featured Forecast

My Favorite Forecasts

    My Recent Locations

    Jesse Ferrell

    Hurricane Harvey becomes national disaster

    By Jesse Ferrell, AccuWeather meteorologist
    8/31/2017, 2:05:32 PM

    Share this article:

    Harvey/Irma Donation Banner


    AccuWeather's Joel Myers gathered key employees into a conference room at AccuWeather today to say that he doesn't think the media is grasping how bad Hurricane Harvey has been, and will be for the future of the United States. His official statements are available on AccuWeather.com, and I generally agree with them. Here's why:

    Meteorologically speaking, it's a record, unprecedented storm. Hurricane Harvey has dropped 25 to 50 inches of rain on Eastern Texas and southwest Louisiana (the white area on this map is over 20 inches in three days - so it's literally "off the charts"):

    Hurricane Harvey 3-Day Rainfall 8/30


    Up until today, there was some question as to whether the record for a continental U.S. tropical storm rainfall, set by Tropical Storm Amelia in 1978, had been broken. I had doubts about the data from some of the Harris County Flood Network data yesterday* but as of this morning, at least one Cooperative Observer station recorded over 48 inches, so I think it's likely that we do have a new record.

    It also happened over a very large area. Unlike Tropical Storm Allison, the most recent powerful rain storm that was held up as the last big event in Houston, and which dropped 20-30 inches of rain over a narrow corridor of Houston, Harvey has inundated the entire county with more than 2 feet (see maps below). The difference, frankly, is staggering.

    Tropical Storm Allison 2001 Rainfall - Harris County, Texas

    Hurricane Harvey Rainfall - Through 8/30 - Harris County Texas


    Harvey's flooding also extended beyond Harris County, Texas. In fact, some of the heaviest rain fell last night, with radar estimating up to 7 inches of rain per hour and 30 inches total! This is probably an overestimate; gauges are more sparse here, but one CoCoRAHs gauge did indicate over 15 inches. Port Arthur is "underwater" today while major roads to Beaumont are closed. Now, we're talking about a much larger area, and the storm is still ongoing. Not only is Houston more populated than New Orleans, we're talking about a much larger area. The population of the area that got hit with winds and flooding is over 6,000,000.


    The areas hardest hit may not yet be accessible. Like Hurricane Katrina, the death count started low, but will rapidly increase in the days and weeks afterwards. Incredible human suffering will follow - Houston is the oil and chemical capital of the country and much of the water may be toxic. Add to this continuing power and sewer outages, things get worse. We could even be talking about Harvey causing Zika to get a foothold once again in the U.S. High temperatures and humidity (normal for this time of year) will exacerbate problems if power remains out. Gas prices are going up; Joel thinks the GDP, and hence economy, for the entire nation will suffer.

    Static Harvey Hardships Ahead


    The NWS lists the highest total rainfall reports from Hurricane Harvey as follows:

    Texas:

    • Cedar Creek Bayou (HCFWS): 51.88 inches*
    • Clear Creek @I-45 (HCFWS): 49.40 inches*
    • Dayton (CoCoRAHs): 49.23 inches
    • Mary's Creek @ Winding Road (HCFWS): 49.20 inches
    • Beaumont Airport: 47.35 inches
    • Santa Fe (CoCoRAHs): 46.70 inches

    Louisiana:

    • Bayou Conway: 22.25 inches
    • Bayou Toro: 20.62 inches
    • Kenner Gully: 18.23 inches
    • Old Town Bayou: 18.15 inches
    • W-14 @ Joe Spears Road: 17.85 inches

    *HISTORY OF THE RECORD-BREAKING RAINFALL CLAIM:

    Yesterday afternoon, meteorologists (including me, live on Facebook) anxiously awaited the rain totals at the Harris County Flood Network to exceed 48 inches, which would beat and then tip over 50 inches, a new meteorological territory. At 11:08 a.m., on Aug. 29, the National Hurricane Center declared the record (preliminary) broken:


    At 5:13 p.m., the Associated Press removed the "preliminary" and stated the NWS had said the record was broken:


    In general, records shouldn't be declared broken until the World Meteorological Organization can confirm it -- a process that can has taken as long as 14 years. I had taken a quick look at the data and it appeared to not be off by a large factor compared to other gauges in the network, so I carried forth the note about the preliminary record.

    After a deeper dive into the data yesterday afternoon, however, I found a number of key problems with the Cedar Bayou gauge data, as well as the two runners-up: Clear Creek and Mary's Creek.

    Problems with Harris County Flood Gauge Data


    The Cedar Bayou gauge looked way off, all day, compared to nearby gauges for 6-hour precipitation data, often being 3-5 times as much. The Mary's Creek gauge had suspicious, repetitive data all night before the record was set, and zeroes when it was obviously raining yesterday. The most believable gauge, Clear Creek, had some fairly outrageous hourly rainfall totals early in the morning of Aug. 27, adding up to over 17 inches while no nearby gauges recorded over 14. Still, this is probably the most reliable reading of the three.

    In any case, today after the CoCoRAHs report came out, the record is preliminary broken even if you throw out all three of these stations. But, we may have not exceeded 50 inches.

    The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com

    Comments

    Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.

    Jesse Ferrell