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<span-size:10.0pt;font-family:"Courier New"">WTNT44 KNHC 241748
<span-size:10.0pt;font-family:"Courier New"">TCDAT4
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<span-size:10.0pt;font-family:"Courier New"">Hurricane Harvey Special Discussion Number 17
<span-size:10.0pt;font-family:"Courier New"">NWS National Hurricane Center Miami FL AL092017
<span-size:10.0pt;font-family:"Courier New"">100 PM CDT Thu Aug 24 2017
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<span-size:10.0pt;font-family:"Courier New"">This special advisory is being issued to update Harvey's initial
<span-size:10.0pt;font-family:"Courier New"">and forecast intensities through the 48-hour period. The storm
<span-size:10.0pt;font-family:"Courier New"">surge values in the public advisory have also been updated based on
<span-size:10.0pt;font-family:"Courier New"">the new intensity forecast.
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<span-size:10.0pt;font-family:"Courier New"">Recent data from Air Force Reserve and NOAA Hurricane Hunter
<span-size:10.0pt;font-family:"Courier New"">aircraft indicate that Harvey's maximum sustained winds have
<span-size:10.0pt;font-family:"Courier New"">increased to 75 kt. The Air Force plane measured maximum 850-mb
<span-size:10.0pt;font-family:"Courier New"">flight-level winds of 88 kt and reliable SFMR winds around 75 kt.
<span-size:10.0pt;font-family:"Courier New"">Based on the hurricane's current rate of intensification, the
<span-size:10.0pt;font-family:"Courier New"">forecast intensities at 12 and 24 h have been raised by 15 kt,
<span-size:10.0pt;font-family:"Courier New"">with a 10-kt increase at 36 h. There are no changes to the track or
<span-size:10.0pt;font-family:"Courier New"">wind radii forecast with this special advisory.
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<span-size:10.0pt;font-family:"Courier New"">It is critical that users not focus on the exact forecast track
<span-size:10.0pt;font-family:"Courier New"">of Harvey, since cycle-to-cycle adjustment are likely. All
<span-size:10.0pt;font-family:"Courier New"">locations within the hurricane and storm surge warning areas should
<span-size:10.0pt;font-family:"Courier New"">be preparing for the possibility of major hurricane-force winds and
<span-size:10.0pt;font-family:"Courier New"">life-threatening storm surge.
<span-size:10.0pt;font-family:"Courier New"">
<span-size:10.0pt;font-family:"Courier New"">Note that this special advisory takes the place of the scheduled
<span-size:10.0pt;font-family:"Courier New"">100 PM CDT (1800 UTC) intermediate advisory.
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<span-size:10.0pt;font-family:"Courier New"">Key Messages:
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<span-size:10.0pt;font-family:"Courier New"">1. Harvey has intensified rapidly, and is forecast to be a major
<span-size:10.0pt;font-family:"Courier New"">hurricane at landfall, bringing life-threatening storm surge,
<span-size:10.0pt;font-family:"Courier New"">rainfall, and wind hazards to portions of the Texas coast.
<span-size:10.0pt;font-family:"Courier New"">Preparations to protect life and property should be completed by
<span-size:10.0pt;font-family:"Courier New"">tonight, as tropical-storm-force winds will first arrive in the
<span-size:10.0pt;font-family:"Courier New"">hurricane and storm surge warning areas on Friday.
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<span-size:10.0pt;font-family:"Courier New"">2. A Storm Surge Warning is in effect for much of the Texas coast.
<span-size:10.0pt;font-family:"Courier New"">Life-threatening storm surge flooding could reach heights of 6 to 12
<span-size:10.0pt;font-family:"Courier New"">feet above ground level at the coast between the north entrance of
<span-size:10.0pt;font-family:"Courier New"">the Padre Island National Seashore and Sargent. For a depiction of
<span-size:10.0pt;font-family:"Courier New"">areas at risk, see the Storm Surge Watch/Warning Graphic at
<span-size:10.0pt;font-family:"Courier New"">hurricanes.gov.
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<span-size:10.0pt;font-family:"Courier New"">3. Life-threatening flooding is expected across much of the Texas
<span-size:10.0pt;font-family:"Courier New"">coast from heavy rainfall of 12 to 20 inches, with isolated amounts
<span-size:10.0pt;font-family:"Courier New"">as high as 30 inches, from Friday through early next week. Please
<span-size:10.0pt;font-family:"Courier New"">refer to products from your local National Weather Service office
<span-size:10.0pt;font-family:"Courier New"">and the NOAA Weather Prediction Center for more information on the
<span-size:10.0pt;font-family:"Courier New"">flooding hazard.
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<span-size:10.0pt;font-family:"Courier New"">4. The Potential Storm Surge Flooding Map is available on the NHC
<span-size:10.0pt;font-family:"Courier New"">website. This product depicts a reasonable worst-case scenario -
<span-size:10.0pt;font-family:"Courier New"">the amount of inundation that has a 10 percent chance of being
<span-size:10.0pt;font-family:"Courier New"">exceeded at each individual location. This map best represents
<span-size:10.0pt;font-family:"Courier New"">the flooding potential in those locations within the watch and
<span-size:10.0pt;font-family:"Courier New"">warning areas.
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<span-size:10.0pt;font-family:"Courier New"">FORECAST POSITIONS AND MAX WINDS
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<span-size:10.0pt;font-family:"Courier New"">INIT 24/1800Z 24.4N 93.6W 75 KT 85 MPH
<span-size:10.0pt;font-family:"Courier New"">12H 25/0000Z 24.9N 94.2W 85 KT 100 MPH
<span-size:10.0pt;font-family:"Courier New"">24H 25/1200Z 26.0N 95.3W 105 KT 120 MPH
<span-size:10.0pt;font-family:"Courier New"">36H 26/0000Z 27.3N 96.3W 110 KT 125 MPH
<span-size:10.0pt;font-family:"Courier New"">48H 26/1200Z 28.3N 97.0W 100 KT 115 MPH...INLAND
<span-size:10.0pt;font-family:"Courier New"">72H 27/1200Z 29.0N 97.7W 40 KT 45 MPH...INLAND
<span-size:10.0pt;font-family:"Courier New"">96H 28/1200Z 28.5N 97.5W 35 KT 40 MPH...INLAND
<span-size:10.0pt;font-family:"Courier New"">120H 29/1200Z 28.5N 96.5W 30 KT 35 MPH...INLAND
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<span-size:10.0pt;font-family:"Courier New"">$$
Forecaster Berg