Tropical Storm Beryl was officially declared by the National Hurricane Center at 10:00pm Central Time Friday night, and the system has strengthened a little overnight. The 4:00am Central Time advisory has Beryl’s wind speeds up to 50 mph now and pressure down to 1000mb. Tropical Storm Beryl is moving generally westward at 21 mph but will begin taking a bit more of a WNW track as we go through the day and into Sunday. Beryl is officially forecast to become a hurricane before daybreak Sunday morning and approach the Lesser Antilles on Monday as a Category 2 hurricane. Forecast model guidance and the favorable environment suggests Beryl may even be a little stronger than that by that time. From there, Beryl is forecast to track through the Caribbean through the week ahead as a hurricane, but there is a lot of uncertainty the deeper we head into next week…
As mentioned, the environment near and ahead of Beryl’s track over the short-term (the next three days or so) is definitely favorable for further intensification. Sea surface temperatures are in the mid 80s or warmer through the entire Caribbean back through the Antilles and into the central Atlantic. These sea surface temperatures are actually running a bit above average, as they have been for the past several months. And the warm water is not just at the surface. Beryl is heading into higher oceanic heat content (warmer water through a deeper column of the ocean) as the system tracks westward, and oceanic heat content is at substantially high values through the majority of the northern 2/3 to 3/4 of the Caribbean. There is a bit of wind shear to the west of Beryl from an upper-level trough, but that trough is moving westward as Beryl is moving westward, keeping the wind shear centered away from Beryl’s circulation and actually acting to ventilate the tropical storm with upper-level outflow instead of shearing it. Beryl has been tracking near some dry air and Saharan dust in the mid to upper levels of the atmosphere, but that has done very little to disrupt the system, and Beryl is now moving away from that dry air and dust. Overall, conditions are favorable for Beryl to intensify into a hurricane and possibly overperform expectations a little bit over the next 48 to 72 hours.
Models are overall in pretty decent agreement through Tuesday or Wednesday that Tropical Storm Beryl will continue tracking west-northwest through the eastern half of the Caribbean and be somewhere south of Hispaniola by early Wednesday. From there, models begin to diverge do to the placement of the upper-level ridge to the north over the North Atlantic and, more importantly, the actual modeled intensity of Beryl as we head into the middle of the week. In this situation, a stronger Beryl will take a more northwesterly track with time because of being steered by deeper-layer flow, whereas a weaker Beryl will be more embedded in the low-level easterly trade winds and will track more westward/southward with time. While there is definitely some disagreement in the models with both the strength of Beryl by midweek and how far north the system is by Wednesday, the basic overall consensus is for a more W to WNW track with time to be likely.
The overnight run of the Euro model does strengthen Beryl in the near term but has a weaker system than other model guidance, even in the now-48 hour timeframe when we know that Beryl is in a strengthening phase and the environment is favorable for the system to become a hurricane. That may have some implications down the road on the eventual track. The Euro often performs better than the GFS with tropical systems, but if it isn’t accurately modeling the intensity of the system, that may not be the case. Still, the Euro takes Beryl on a W to WNW track into the east-central Caribbean before weakening it significantly and sending it westward into Central America by the second half of the upcoming week. This is currently the western/southernmost plausible track solution in the set of them that seem to be respectably possible.
The GFS, on the other hand, is probably the northernmost of the plausible/believable model solutions, and that’s because it has a stronger Beryl in the short-term approaching the Lesser Antilles and the eastern Caribbean through the next 48-72 hours. While the GFS can often develop systems in the long-range that never materialize and can sometimes perform not as well as the Euro in terms of track, it seems to be handling current things better than the Euro at the moment, and that lends credibility to at least the shorter-range portion of the model run. GFS takes what would be a Hurricane Beryl into the east-central Caribbean but lifts it more northwest with time earlier on because of the stronger intensity. This allows Beryl to interact with the mountains of Hispaniola causing it to SIGNIFICANTLY weaken. Because of its more northerly placement, the system, despite tracking WNW, is able to be more northward than the Euro and reach the Yucatan Strait by the end of the week. In normal circumstances, this kind of placement would significantly increase the chances of a Gulf of Mexico type threat. However, because of the significant disruption of the inner core and the weakening that results, if the GFS run here is right, it wouldn’t matter… as Beryl would be a dying tropical system despite its placement on the map.
The actual truth is likely somewhere in between the Euro and the GFS, and that’s where a majority of the tropical models and ensembles are tracking… not as far northwest as the GFS to be able to interact with Hispaniola, but not as far south/west as the Euro to glide right into Central America.
Beryl’s long-term track (assuming the system survives all the way across the Caribbean in the first place, that’s not a guarantee yet) won’t be determine just by its intensity but also by the upper-air pattern over the United States into the western Atlantic as we head toward the end of the week and the beginning of next weekend… and there is model disagreement there too! The GFS takes the upper-level ridge that will be overtop us the middle of the week and shifts it out into the western Atlantic by the end of the week as an upper-level trough of low pressure sets up over the Great Lakes. That causes a big weakness in the ridge over the Southeast down into the Gulf, and that would allow whatever Beryl is at that point to have a CHANCE to turn more northwest or north into the Gulf. HOWEVER, like we mentioned above, if the GFS is right… it wouldn’t even matter because of how much damage Hispaniola would do to the system.
The Euro, on the other hand, does still have the approaching upper-level trough but is slower with its timing. It’s still moving the upper ridge over us eastward too, but it’s doing it at a slower pace. That causes the ridge to be centered over the Southeast coast into Florida by the end of the week, and that also cuts down on how much of a weakness there is in the ridge over the Gulf of Mexico. An upper-level pattern like that would more likely result in a more W or WNW tracking Beryl toward the Yucatan and the Bay of Campeche, even if it’s stronger than what the Euro models it as at face value.
Over the last few weeks, the Euro has outperformed the GFS in the extended range in relation to the placement, timing, and intensity of the upper-level ridge over the eastern United States. Historically speaking, the Euro tends to perform better than the GFS with the strength of the subtropical ridge in the summer months in most years anyway. That gives me confidence that it is probably closer to reality with the upper-level pattern late next week, even if it’s not currently modeling the intensity of Beryl itself all that accurately right now. While this could change, that leads me to believe that a Gulf of Mexico type threat (especially a northern Gulf threat) from Beryl isn’t likely at this point, but it’s too soon to set that assumption into stone. There are many moving parts and that can change with time. The bottom line to all that is… pay attention to forecast updates, but don’t be anxious about it or get worried! We’ll continue to track Beryl, and we will provide alerts as necessary if it does start to look like Beryl may become a Gulf threat. At least as of right now, nothing is showing there is a high likelihood of that being the case though!
