JACKSONVILLE, Fla. – 2 a.m. Thursday update: The National Hurricane Center's latest track puts Hurricane Matthew brushing the coast of northeast Florida as a Category 3 hurricane Friday afternoon/evening.
A hurricane warning is in effect for north of Golden Beach in South Florida to Fernandina Beach, Florida. The hurricane warning includes Duval, Clay, St. Johns, Putnam, Nassau and Flagler counties.
Hurricane Matthew continues to hold its current strength as a dangerous category 3 storm. In the latest update, the National Hurricane Center says Hurricane Matthew is expected to strengthen during the next day and is forecast to be a category 4 hurricane as it approaches the east coast of Florida.
Located: 295 miles southeast of West Palm Beach, Florida
Maximum sustained winds: 115 mph
Minimum pressure: 954 mb
Movement: NW at 10 mph
Even though Matthew's winds have remained steady at 115 mph, we are seeing signs that the storm is responding to the more favorable environment it's moving into, most significantly, a drop in pressure and a contracting eye.
Hurricane-force winds extend outward up to 45 miles from the center and tropical-storm-force winds extend outward up to 175 miles.
The contracting eye is important due to a law of physics called the Conservation of Angular Momentum. This law simply states that if the radius of a spinning object contracts, then there MUST be a corresponding increase in rotational speed. This is what causes a figure skater to speed up when he or she starts a spin with both arms and even one leg extended out to the side, and then brings those arms and leg in tight -- you see their spin speed up dramatically.
So, when a hurricane has a distinct eye and it begins to contract, we expect wind in the eye wall to increase as well, and that likely will occur overnight.
As you know, water is usually the most destructive aspect of a hurricane, both from rain received and from storm surge. Depending upon the timing of the water’s rise in relation to our high tide, there is the distinct possibility for life-threatening coastal inundation Friday into Friday night.
If peak storm surge coincides with high tide, then surges of 5 to 8 feet are possible. As for rainfall, totals approaching 7 inches are possible, with isolated amounts of 10 inches not out of the question.
Timing appears to be as follows: Conditions should start deteriorating late Thursday night, and steadily go downhill early Friday. You’ll notice periodic showers and thunderstorms as outer rain bands cross our area, and wind increasing – although the stronger gusts will be in the rain bands.
Tropical storm conditions should be widespread by around late-morning Friday, with hurricane conditions developing during the afternoon.
Again, the eye of the storm will track nearly straight up Florida’s east coast. There is very little margin for error: if the path slides a bit west and the eye goes west of us, then the strongest “right hook” winds get us. If the eye stays a little offshore, we’ll still get very strong wind, but not as high-end as if the eye goes to our west…pray for a farther east path. It just all depends on when Matthew starts that curve to the north-northeast.
As you would expect, there will be significant coastal erosion in Matthew’s wake.
This is a very dangerous storm, and you should rush all preparations to completion, as Thursday will be your last opportunity. If you are in a particularly flood-prone or inundation-prone area, then it would be a good idea to have your car fueled, packed and ready to go if you are ordered to evacuate.
If you are sheltering in place, make sure that you have non-perishable food and water to get you through at least a few days (the rule of thumb is a gallon of water per day, per person). Also make sure that your cell phones and wireless devices are charging right up until the time the power goes out. It’s also a good idea to let some friends or relatives who live far from our area know your plans.
Stay alert as Matthew will be a massive storm and although the greatest risk for Jacksonville will likely be along the immediate coast in the form of life-threatening rip currents, heavy surf, some beach erosion, small craft advisories along with coastal downpours, subject to change based upon new Hurricane Hunter data and forecasts.