Watching Hurricane Maria Closely Along The East Coast

Hurricane Maria made landfall in Puerto Rico early Wednesday morning as a strong category 4 hurricane, leaving the entire island without power and a path of destruction. Maria underwent an eye wall replacement cycle last night, which resulted in the maximum sustained winds lowering from 175 mph to 155 mph before landfall. However, this also resulted in an expansion of the wind field, which may have caused the Virgin Islands to be more heavily impacted. The passage of Maria over Puerto Rico disrupted the system, bringing it down to category 2 strength, but with time, Maria should regain strength and become better organized once again.

Over the last several days, Maria has been able to thrive in a low-shear environment, which is one of the reasons why this system underwent rapid intensification. In the immediate term, wind shear should remain relatively low. Currently, wind shear is heightened to the west, north, and east of Maria; however, this can mostly be attributed to the outflow that is coming off of the hurricane and will actually enhance further strengthening of Maria. It is worth mentioning that an upper-level shortwave located just to the southeast of Florida could be responsible for some of the wind shear to the west of Maria, but Maria is far enough to the east that it is not being negatively impacted by this shear. The shear tendency analysis confirms that shear has been on the increase in locations all around Maria, but shear has tended lower in the immediate vicinity of Maria. Again, this is mostly due to outflow coming off of the system, and this configuration of low/high shear values over and around the system should remain predominant over the next couple of days.

The steering flow near Maria is not particularly strong, but the system will generally move northwestward before making an even more northward turn over time. On the steering flow analysis, the features that are most noteworthy are the outflow coming off of Maria, the building ridge over the eastern United States, the weak trough moving off the East Coast, the longwave trough over the western U.S., and Jose. Many of these features could potentially have an impact on the future strength and movement of Maria.

Through the rest of the week and into the weekend, Maria should be able to strengthen, given that wind shear should remain relatively weak in the short term. However, a positively tilted, mid to upper-level trough will be positioned over the southeast underneath the building, deep-layer ridge over the northeast. This only gives Maria about a 3-day window to really begin to regain strength before being more heavily influenced by the southwesterly shear on the east side of the trough. Before that occurs, Maria will be moving through a region where sea surface temperatures currently run from 29-30°C, which will provide the necessary energy for additional strengthening. The National Hurricane Center has Maria reaching category 3 strength again with winds topping out at 115 mph, but if Maria can recover quickly enough from being negatively impacted by Puerto Rico, it may have enough time to get a bit stronger than that. However, Maria shouldn’t get close to the peak intensity that it reached on Tuesday.

The big question that remains is whether or not Maria will actually make a landfall along the East Coast or get close enough to be impactful. Tropical Storm Jose should manage to keep a well-established weakness in place between the building ridge over the northeast and the ridge near Bermuda, allowing Maria to safely move between those two features in the short term. Also, the positively-tilted trough mentioned above should also have an influence on keeping Maria away from Florida, Georgia, and probably even South Carolina. However, as Jose weakens significantly this weekend, Bermuda ridging and the ridge over the northeast could actually merge, which could allow Maria to make a northwestward jog towards the East Coast sometime next week. The timing of a longwave trough that will be digging into the eastern United States later next week and whether or not the two ridges merge will determine just how close Maria gets to the East Coast. If the longwave trough makes it eastward quickly enough, this would steer Maria safely out to sea, but it’s not guaranteed that this will occur before Maria makes it pretty close to the coast. Residents from the North Carolina coast to the Massachusetts coast need to monitor Maria closely. The good thing is that the sea surface temperatures are very cool along and just off the Mid-Atlantic and Northeast coasts, so if Maria managed to get close, weakening most definitely would occur. This still doesn’t mean that there wouldn’t be some major impacts to those areas, if this scenario unfolds. Again, the second scenario is a safe passage out to sea.

Bullet-Point Summary:

• Maria could recover enough to regain additional strength over the next 3 days, but weakening should begin to occur afterwards.
• Maria will generally travel northwestward before making a more northward turn in the short term.
• Maria could make a jog northwestward next week as Bermuda ridging and ridging over the Northeast potentially merge.
• Residents from the North Carolina coast to the Massachusetts coast need to monitor Maria closely. If this occurs, impacts would occur mid next week.
• The second scenario is that Maria will go safely out to sea with little to no impact, so don’t panic.