New 5 PM Update with Some Changes For Marco and Laura
- Laura has strengthened to 60 mph maximum sustained winds. The NHC is now calling for it to get up to 105 mph, but they said it could threaten the northwestern Gulf coast near major hurricane strength (Cat 3). These are their comments regarding the intensity forecast: "The intensity forecast during the next 24 hours is highly dependent on the track and the amount of interaction Laura has with Cuba. If the storm stays along the southern coast or just offshore, the environment of warm water and low vertical wind shear could allow for some slight strengthening, but little overall change in intensity is indicated during the next 24 hours. After the center clears western Cuba, the upper-level wind pattern is predicted to
quite favorable while the storm traverses the warm waters of the Gulf of Mexico. The GFS, UKMET, and regional hurricane models all indicate significant deepening, and the NHC intensity forecast has been adjusted slightly upward. Although not explicitly shown, Laura could threaten the northwestern Gulf coast near major hurricane strength."
- Marco is still a hurricane with maximum sustained winds of 75 mph, but it's starting to feel the effects of wind shear, and it's expected to decouple before it gets to the coast. This what I meant when I said it will be weakening on approach and why I have been much more worried about Laura. The maximum storm surge forecast has been lowered to 3 to 5 feet from 4 to 6 feet. This is from the NHC: "By Monday night, the shear is forecast to increase to close to 40 kt, which should strip the convection away from the center of the cyclone, causing it to weaken." Also, this is what they say regarding the track: "there has been a major shift in the track guidance beyond Monday morning, and the majority of the forecast models now keep Marco offshore of the northern Gulf coast for the next few days rather than moving it inland over Louisiana Monday afternoon. Since this shift was so abrupt, I would rather split the difference between the previous official forecast track and the latest consensus tracks until another round of model runs can confirm this new suggested track is higher confidence. Based on this shift in track, tropical storm conditions are expected farther west along the Louisiana coast, and a Tropical Storm Warning has been issued from Morgan City to Cameron, Louisiana. It should be noted that if the trend in the models are correct, some of the impacts over portions of the north-central Gulf coast could be lessened."