Subtropical Storm Beryl formed yesterday as expected, and is now a well-defined area of low pressure due east of Savannah, Georgia. Thunderstorm activity is a bit lacking this morning, and the circulation is a bit naked. The reason Beryl looks worse today is because she has become vertically stacked beneath the upper low that was to her west yesterday, and thus she has lost baroclinic support, and is being forced to use tropical processes (thunderstorms) to maintain herself. Ship reports indicate she hasn’t really weakened, but she definitely has not strengthened since last night either. A recon plane will investigate her in a couple of hours to better gauge her strength. As discussed previously, the limiting factor for Beryl is dry air being entrained from her west. She has more moisture available than Alberto did, but it will still be difficult for her to sustain heavy convection over her center. Beryl will be moving over the Gulf Stream tonight, with SSTs 1.0-1.5C warmer than what she is currently over, and that should help her increase convective activity. Popcorn convection bands are apparent in visible imagery wrapping in towards the center, indicating that the environment is still unstable enough to allow thunderstorm development if enough moisture convergence is present. Again, warmer waters will likely help that later today.
Beryl should reach peak strength prior to landfall, and then weaken slightly just before landfall as she moves over the cold shelf waters off the coastline. Beryl’s peak intensity should still reach near 60mph if she can develop convection tonight. If she fails to do this, her maximum winds will remain near 45mph until landfall. The ECMWF last night showed Beryl deepening to 997mb before landfall, supporting the idea that she can still strengthen slightly into a moderate tropical storm. Models are coming into tighter agreement on landfall right in the center of the window outlined yesterday, near Jacksonville, Florida plus or minus 30-40 miles or so. After moving inland, the blocking ridge that forced Beryl into the coast will break down in the face of a longwave trough moving across the northern U.S., and this should bring Beryl out to the northeast near the coastline of the Carolinas. If she makes it back over the water, redevelopment may be possible. Some models develop her into a stronger tropical cyclone as she moves out to sea than she ever was before landfall. The outer banks of North Carolina may have a blustery day if this occurs. For all of the southeastern states, this track will bring a few inches of rainfall to the drought-stricken areas that need it badly. It isn’t enough to bust the drought, but it’s rain.
Overall, Beryl is not a significant threat wind-wise, and will be more beneficial than not with her rainfall. A moderate tropical storm is expected at landfall, near 60mph in strength. This is a bit stronger than the NHC’s peak intensity forecast of 50mph. After Beryl, the Atlantic should be quiet for at least a couple of weeks, and significant activity may not return until the 2nd half of June due to an unfavorable pressure pattern over North America. Alberto and Beryl are not signs of an above-average season since they were not purely tropical developments, and 2012 should still come in at the end as a near-average season.
We shall see what happens!