For the last several days we’ve been watching a disturbed area of convection south of the Yucatan Peninsula show small signs of tropical development. Over the last 24 to 36 hours though, we’ve seen this cluster of convention become a fairly well organized tropical storm, gaining the name “Michael” in the process and nearly reaching hurricane status this morning with winds hovering around 70 mph. Things have quickly become quite worrisome for Michael. What many thought would be a weak tropical system making landfall somewhere along the Gulf Coast now appears to have the potential to become a serious hurricane.
Thus, rather than your normal 5 Thing to Watch This Week, we’ll be doing a special edition focused on Tropical Storm Michael and the significant impacts it may bring to Florida and the Gulf Coast later this week.
Rapid Intensification Possible as Michael Nears Hurricane Status:
- Tropical Storm Michael will likely be upgraded to a hurricane later today with sustained winds above 75 mph.
- There is currently a fair amount of shear around Michael, preventing the storm from going through rapid intensification right away. As the storm drifts further to the north and into the Gulf of Mexico, this shear should relax and allow for quicker strengthening.
- Michael is very large in size. This is helping to slow down strengthening just a bit, but could mean a wider scope of impact once entering the Gulf and eventually making landfall. The core won’t tighten up for a little while, but once it does, watch out.
In just a 24 hour time period, we’ve seen Michael go from a disorganized tropical storm to near-hurricane status as it travels between the Yucatan Peninsula and the western tip of Cuba. Convection is exploding all around the storm system this morning as it attempts to become vertically stacked and less lopsided. As soon as thunderstorms can wrap entirely around the storm’s center and shear relaxes a bit, do not be surprised to see Michael go from 70 mph sustained winds to 100+ mph. Rapidly strengthening storms headed into the Gulf of Mexico in early October can become major threats very quickly, and with nowhere else to turn but towards land, anything that does rapidly develop becomes a major threat.
Landfall & Impacts:
- Damaging winds at impact: Guidance is in solid agreement that Michael makes landfall as a strong or major hurricane between the Florida/Mississippi border and the big bend of the Panhandle. Areas within 50-100 miles of this landfall could experience sustained winds of 100+ mph along with serious high storm surge, making for a very nasty and potentially devastating scenario.
- Flooding will be a major issue: As with all tropical systems, especially recent ones like Florence, flooding will be a big problem. Guidance seems to be locked into 5-10+ inches of rainfall for a large area near and relatively far from direct landfall on Wednesday. This will include inland regions in parts of Georgia and the Carolinas.
- Speed at landfall: There’s some decent discrepancy concerning Michael’s forward speed at landfall. Some guidance shows Michael slowing down just prior to impact, allowing more time for strengthening and higher impacts. Other guidance seems to think that landfall will occur faster. This would still mean very high impacts, but possibly not as strong nor as prolonged. We’ll be watching this closely over the next few days.
With a mid-week landfall likely, Tropical Storm Michael has nearly 3 days to take full advantage of the warm waters and healthy environment of the Gulf of Mexico. The majority of guidance and ensembles are in strong agreement that once clearing the pass between the Yucatan and Cuba, quick intensification is likely. In fact, there is fairly strong agreement of Michael dipping below 965 mb at landfall, meaning category 2+ strength (likely a major hurricane in that scenario).
- Tropical Storm Michael will likely move into the Southeast region at the end of this week, potentially dropping 3-6+ inches of rainfall. With highly saturated grounds and recent flooding, this could mean major issues for states like Georgia, South Carolina, North Carolina, and even areas in the Mid-Atlantic.
- Gusty/damaging winds could still remain an issue. Weak hurricane/strong tropical storm conditions will remain possible even as Michael exits the east coast just to the south of the Mid-Atlantic. Impacts will certainly be widespread.
- The Mid-Atlantic and Northeast aren’t out of the woods. The entire eastern seaboard has seen a wild year of heavy rainfall and flooding, so any additional major systems are likely to cause more issues. With Michael expected to move across the eastern seaboard at the end of the week and over the weekend, flooding will become a serious concern.
As we briefly mentioned above, Michael’s impact won’t be limited to just where it makes landfall. After making landfall somewhere near the Florida Panhandle, Michael will likely continue on a northeasterly trajectory, moving into the southeastern US. Hurricane Florence did damage to this region just few weeks ago, with high rivers and flooding still an issue for many locations across the Carolinas. With guidance showing the potential for an additional 3-6+ inches of rainfall and gusty winds, we could be talking about more major issues for this region.
Above is the latest predictions from our team here at WeatherOptics. We will be continually reanalyzing and redefining these threat/impact zones over the next day or two. Our highest area of concern for now remains from the Florida/Mississippi border to the big bend of the Florida Panhandle. More updates from our team on Michael to come later today.