Update - May 25, 7:30PM EDT
With the shear over 94L's western side still in excess of 40 knots, and diffluence spreading out its eastern half like a leaf, trying to find an appropriate description is a challenge. As of this evening, Invest 94L far more closely resembles a Tropical Storm undergoing, and better than half way through, extratropical transition, rather than a non-tropical cyclone undergoing tropical transition.
As can be seen in the visible image above, 94L does boast solid convection in its center, but only within a fraction of the center, up at its very top - being ignited and reignited by diffluent southerly winds, and likely less so from a warm core heat engine, which in this cyclone is probably still shallow.
With shear expected to gradually slacken to less unfavorable levels over the weekend, 94L now has very good odds of becoming a named subtropical or tropical storm by this time Sunday, and probably sooner.
Models continue coalescing on a "C" loopy back to the southeast coast, and a bit inland, before ejecting 94L up to the north-northeast and ultimately back out to sea, with a potential 'landfall' somewhere between northeast Florida and North Carolina, which for many could provide beneficial rains, if verified. Intensity probably remains more difficult for the models to get a handle on, but should be limited by 94L's initial subtropical nature, a huge swath of dry air along the southeast to contend with, and limited time over ideally warm waters.
Update- May 25th, 546AM EDT
The small dot in the center of the convection May be a Convective Hot Tower, or CHT. I don't recall seeing a CHT in an unnamed system before. With this system I guess anything is possible. Something to keep an eye on. The RBTOP Enhancement is used here to denote the colder colors and the CHT. New enhancement for 2012.
Update - May 25th, 12AM EDT
Weak low is now located just north of the northwestern Bahamas and moving northeast at 16kts. Sustained winds are 35kts to the northeast of the center and central pressure is now 1007mb. All convection remains displaced to the northeast of the center.
Latest model projections suggest that if the high pressure ridge to the north blocks the system and retrogrades it to the west or west northwest the probable area of concern would be farther north along the southeast coast . This would likely keep the heavier precipitation and stronger winds north of the Florida peninsula and more toward the Carolinas. All of this assumes additional strengthening, however, the NHC chances for further development of the system within the next 48 hours to a Subtropical or Tropical Storm has increased to 60 percent.
Original Post - Thursday, May 24th, 4:15PM EDT
The area of low pressure designated as Invest 94L has become better organized since Wednesday evening and at 05/18Z the center was located just southwest of Islandia, Florida, on Elliott Key, with sustained winds close to tropical storm force - mainly offshore to the northeast of the center, however, some locations in extreme South Florida are already experiencing wind squalls gusting to about 50 knots - and with a central pressure of 1008mb. The system is moving to the north northeast at 12 knots and, as high pressure builds to the north of the system, the forward speed is expected to decrease.
The convection is displaced well to the north and east of the center and, like Tropical Storm Alberto earlier this month, the system is influenced by the Gulf Stream SSTs of 27-28C. The shallow system remains beneath the influence of the stronger southwesterly flow at 300mb. Some additional development is possible - probably subtropical in nature. There is a chance that the building high pressure to the north will trap the system and nudge it back toward the Florida peninsula. Frequent showers and thunderstorms are likely over south Florida this evening but the stronger squalls should remain offshore.
If the high pressure increases to the north and indeed blocks the low and retrogrades it back toward the central Florida peninsula, the latter part of the upcoming Memorial Day holiday weekend could get very wet and windy along the Florida east coast. Folks from Florida and the northern Bahamas north to South Carolina should continue to monitor this developing system through the holiday weekend. If the system should attain Subtropical or Tropical Storm status, the next name on the list this year is Beryl.