NOAA // US Gulf - Tropical Storm Michael
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<span-size:10.5pt;font-family:"Courier New";color:black">WTNT44 KNHC 072101
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<span-size:10.5pt;font-family:"Courier New";color:black">Tropical Storm Michael Discussion Number 5
<span-size:10.5pt;font-family:"Courier New";color:black">NWS National Hurricane Center Miami FL AL142018
<span-size:10.5pt;font-family:"Courier New";color:black">400 PM CDT Sun Oct 07 2018
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<span-size:10.5pt;font-family:"Courier New";color:black">Deep convection has continued to develop over the eastern
<span-size:10.5pt;font-family:"Courier New";color:black">semicircle of the cyclone, and data from the reconnaissance
<span-size:10.5pt;font-family:"Courier New";color:black">aircraft indicate that the center has re-formed farther east,
<span-size:10.5pt;font-family:"Courier New";color:black">closer to the convection. The Air Force aircraft has measured peak
<span-size:10.5pt;font-family:"Courier New";color:black">925-mb flight-level winds of 56 kt, and believable SFMR winds of
<span-size:10.5pt;font-family:"Courier New";color:black">40-45 kt. Based on these data, the initial wind speed has been
<span-size:10.5pt;font-family:"Courier New";color:black">increased to 45 kt.
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<span-size:10.5pt;font-family:"Courier New";color:black">Due to the center reformation, the initial motion estimate is a
<span-size:10.5pt;font-family:"Courier New";color:black">highly uncertain 020/3 kt. The overall forecast reasoning has not
<span-size:10.5pt;font-family:"Courier New";color:black">changed much since the previous advisory. Although there could be
<span-size:10.5pt;font-family:"Courier New";color:black">some additional eastward re-formation of the center, the tropical
<span-size:10.5pt;font-family:"Courier New";color:black">storm is forecast to begin moving northward between a ridge over the
<span-size:10.5pt;font-family:"Courier New";color:black">western Atlantic and a deep-layer trough over the west-central
<span-size:10.5pt;font-family:"Courier New";color:black">United States. A general northward motion at around 10 kt is then
<span-size:10.5pt;font-family:"Courier New";color:black">expected to continue during the next 2 to 3 days. After that time,
<span-size:10.5pt;font-family:"Courier New";color:black">Michael should turn northeastward ahead of an approaching trough.
<span-size:10.5pt;font-family:"Courier New";color:black">The track guidance remains in overall agreement on this scenario,
<span-size:10.5pt;font-family:"Courier New";color:black">however, significant along-track (forward speed and timing)
<span-size:10.5pt;font-family:"Courier New";color:black">differences remain. The HWRF brings Michael onshore the northern
<span-size:10.5pt;font-family:"Courier New";color:black">Gulf coast within 72 hours, while the ECMWF is much slower and has
<span-size:10.5pt;font-family:"Courier New";color:black">Michael still offshore at day 4. The new NHC track has been shifted
<span-size:10.5pt;font-family:"Courier New";color:black">eastward primarily in the short term due to the more eastward
<span-size:10.5pt;font-family:"Courier New";color:black">initial position. The latter portion of the track forecast is again
<span-size:10.5pt;font-family:"Courier New";color:black">close to the consensus aids due to the large along- and cross-track
<span-size:10.5pt;font-family:"Courier New";color:black">guidance spread.
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<span-size:10.5pt;font-family:"Courier New";color:black">Michael has strengthened today despite moderate westerly shear. The
<span-size:10.5pt;font-family:"Courier New";color:black">shear is forecast to gradually decrease over the next couple of days
<span-size:10.5pt;font-family:"Courier New";color:black">while the system moves over warm waters. This should allow for
<span-size:10.5pt;font-family:"Courier New";color:black">steady strengthening and most of the intensity models bring Michael
<span-size:10.5pt;font-family:"Courier New";color:black">to hurricane strength within the next couple of days. It should
<span-size:10.5pt;font-family:"Courier New";color:black">also be noted that the global models also significantly deepen the
<span-size:10.5pt;font-family:"Courier New";color:black">storm over the next 72 hours to pressures below 970 mb. The new NHC
<span-size:10.5pt;font-family:"Courier New";color:black">intensity forecast calls for Michael to become a hurricane in about
<span-size:10.5pt;font-family:"Courier New";color:black">36 hours when the storm reaches the southeastern Gulf of Mexico.
<span-size:10.5pt;font-family:"Courier New";color:black">Additional strengthening is indicated through 72 hours when the
<span-size:10.5pt;font-family:"Courier New";color:black">storm is forecast to be near the northern Gulf coast, and the NHC
<span-size:10.5pt;font-family:"Courier New";color:black">forecast is near the higher SHIPS and HWRF models.
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<span-size:10.5pt;font-family:"Courier New";color:black">Key Messages:
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<span-size:10.5pt;font-family:"Courier New";color:black">1. Michael is expected to produce heavy rainfall and flash flooding
<span-size:10.5pt;font-family:"Courier New";color:black">over portions of western Cuba and the northeastern Yucatan Peninsula
<span-size:10.5pt;font-family:"Courier New";color:black">of Mexico during the next couple of days.
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<span-size:10.5pt;font-family:"Courier New";color:black">2. Tropical storm conditions are expected tonight over portions of
<span-size:10.5pt;font-family:"Courier New";color:black">western Cuba and the northeastern Yucatan Peninsula, where tropical
<span-size:10.5pt;font-family:"Courier New";color:black">storm warnings are in effect.
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<span-size:10.5pt;font-family:"Courier New";color:black">3. Michael is forecast to be a hurricane when it reaches the
<span-size:10.5pt;font-family:"Courier New";color:black">northeastern Gulf Coast by mid-week, and the risk of dangerous storm
<span-size:10.5pt;font-family:"Courier New";color:black">surge, rainfall, and wind impacts continues to increase. In
<span-size:10.5pt;font-family:"Courier New";color:black">addition, Michael is expected to affect portions of the Florida Gulf
<span-size:10.5pt;font-family:"Courier New";color:black">Coast that are especially vulnerable to storm surge, regardless of
<span-size:10.5pt;font-family:"Courier New";color:black">the storm's exact track or intensity. Residents in these areas
<span-size:10.5pt;font-family:"Courier New";color:black">should monitor the progress of this system and follow any advice
<span-size:10.5pt;font-family:"Courier New";color:black">given by local officials.
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<span-size:10.5pt;font-family:"Courier New";color:black">FORECAST POSITIONS AND MAX WINDS
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<span-size:10.5pt;font-family:"Courier New";color:black">INIT 07/2100Z 19.2N 85.5W 45 KT 50 MPH
<span-size:10.5pt;font-family:"Courier New";color:black">12H 08/0600Z 20.1N 85.6W 50 KT 60 MPH
<span-size:10.5pt;font-family:"Courier New";color:black">24H 08/1800Z 21.5N 85.8W 60 KT 70 MPH
<span-size:10.5pt;font-family:"Courier New";color:black">36H 09/0600Z 23.2N 86.2W 70 KT 80 MPH
<span-size:10.5pt;font-family:"Courier New";color:black">48H 09/1800Z 25.0N 86.7W 80 KT 90 MPH
<span-size:10.5pt;font-family:"Courier New";color:black">72H 10/1800Z 29.2N 85.7W 85 KT 100 MPH
<span-size:10.5pt;font-family:"Courier New";color:black">96H 11/1800Z 33.7N 80.4W 50 KT 60 MPH...INLAND
<span-size:10.5pt;font-family:"Courier New";color:black">120H 12/1800Z 39.0N 68.5W 55 KT 65 MPH...POST-TROP/EXTRATROP
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<span-size:10.5pt;font-family:"Courier New";color:black">$$
<span-size:10.5pt;font-family:"Courier New";color:black">Forecaster Brown