This evening, we've still got three tropical systems out in the Atlantic, all lined up in a row: Hurricanes Maria and Nate and Tropical Storm Ophelia. Let's tackle them one-by-one.
Maria is heading out to sea, likely to head for somewhere between Greenland and Iceland over the next few days. Shear began to impact the system a couple of days ago and gave it the apperance of an cyclone -- which it still has to some degree given the frontal-like structures to the south and east of the storm and the dry air intrusion on the south side of the system -- but this evening satellite appearances became more tropical in nature with convection redeveloping near the center. For what it's worth, cyclone phase analyses just recently have suggested that the storm was beginning, not completing, transition. My guess is that the warm core has either been maintained throughout with outflow channels giving the appearance of frontal structures or that the outflow from Nate and Ophelia that has been feeding into the storm helped maintained the warm core aloft. Nevertheless, the storm is heading out to sea and should become in the next 12-18hr.
Nate probably won't be far behind, but not after a brush south of Bermuda. It should remain far enough to the south to not bring hurricane conditions to the island over the next day or so. Nate remains a small storm but has gradually improved in apperance and organization over the past 12hr or so. As I write this, recon is en route to the storm, so we should have a better estimate of its true intensity come morning. Nevertheless, it has begun to move slowly toward the east and northeast and should continue to do so through the forecast period with some acceleration through time. Without a lot of mid-latitude forcing, it appears that a tug from Maria is the most likely culprit towards this movement out to sea. Outflow remains well-established with Nate but is beginning to be impacted on the west side of the storm by the outflow from Ophelia (as drawn into Maria) and to the southeast by an approaching upper-level low. There may be some minor interaction with this feature over the next day or two to keep the storm from accelerating quite so fast to the NE, but this does not change the end-game solution. Ultimately, it'll likely end up being absorbed by the remnants of Maria, as suggested by most of the model guidance, but not until the end of the forecast period (similar to the forecast). Other than adjustments for the current intensity necessitated by recon once it reaches the storm, only minor fluctuations in intensity are expected over the next couple of days before a slow weakening trend commences.
That brings us to Ophelia. Ophelia remains a small, sheared storm, with the center of circulation on the SE side of the convective envelope. While the storm continues to try to develop an eye-like feature, there has been no real increase in organization or intensity corresponding to this as of yet. As long as the shear continues, the storm's intensity will likely be held in check; however, if it abates, it is possible to see the storm start to organize a bit faster. Think of it as the storm having the puzzle pieces together in chunks, but missing the last few pieces to put it all together. Nevertheless, a significant decrease in shear is not likely over the next day or two, merely a change in the direction of the shear (now from the SE due to an upper-level ridge north of Cuba and Hispaniola to from the W & NW due to the midlatitude flow across the SE United States). The statement about the shear increasing further if the storm crosses 30N very much applies here, as the shear due to the midlatitude flow increases by a fair amount the further north you get.
The track forecast thus becomes critical to the intensity forecast, both in terms of the shear and in terms of potential landfall. Ophelia is currently stuck in the midst of a col region, a region of weak steering currents, between the aforementioned upper-level ridge to its SE and the extreme eastern end of an upper-level ridge centered over Oklahoma. This latter ridge has had a hard time building in towards the east and forcing the storm on a westward path into and across Florida. Further, shortwave troughs in the midlatitude flow to the north of the storm aren't really able to reach down and capture the storm and send it out to sea; there's not much to change this significantly in the short-term. It is likely that Ophelia will feel the effects of one of these weak troughs and get tugged a little northward but ultimately not get carried out to sea. What happens from there depends upon what the next feature to impact the storm is -- an upper-level ridge or another trough. As Maria and Nate head out to sea, the potential for upper-level ridging to build in north of the storm increases, but if the storm gets too far to the north before then, it has a greater chance of ultimately heading out to sea.
Coupling this analysis with the available model guidance, a forecast track similar to that of the is the forecast here as well. A slow drift northward over the next couple of days is likely with only modest strengthening over that time. There will be the chance for additional strengthening in the long-term with my 5 day intensity forecast similar to the 's 5-day strength (minimal cat. 1 hurricane) but slower in getting there in days 1-4. A loop in the track is quite possible over the next few days, with the exact timing and positioning of the loop still to be determined. Unfortunately, with little skill in forecasting this, no narrowing of potential landfall regions from Palm Beach northward to the Outer Banks can be made at this time. There is still the potential for this storm to ultimately enter the Gulf of Mexico, but any such threat there would likely be confined to the Florida Panhandle and is still at least 5 days away. Everyone in the potential impact areas should be prepared for a wet and windy weekend with the potential of a landfalling hurricane into next week.
The features in the western Gulf and along the coast of Africa will need to be monitored for development, but the former is poorly-organized and near-shore already and the latter is well out to sea and more likely than not to just spin fish.
More as events warrant.
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