As of early this morning, here are the bullet points:
91L's structure is a blend of subtropical and marginally tropical
91L's weather continues to be most pronounced on its eastern half
Conditions for development have turned from unfavorable to marginally favorable
Conditions for development are forecast to become even better over the next day or two
The broad low pressure area being tracked as Invest 91L has been struggling to organize over the past several days, but conditions are now staring to become marginally favorable for subtropical or tropical development.
As of early Wednesday morning, 91L still consists of a broad surface circulation with multiple, competing swirls about an axis of lower pressure, but this could be starting to change.
Late last night convection started flaring up a little closer to the center, and not so far removed as to be completely auxiliary. Concurrent with this event, pressures have been falling, and wind speeds rising. More recently, night vision IR imagery suggests that a center reformation may be trying to take place closer to the deepest convection. Any one of these by itself may not mean much, but taken together, this is characteristic of a sloppy system getting better organized.
The driving forces that have been holding 91L in check are starting to relax, with both shear and dry air decreasing. With upper level winds now aligning themselves a little with the lower levels, 91L is starting to take on a somewhat classic subtropical cyclone look.
At the surface, observations show winds now up to around 35 MPH sustained, with higher gusts. Most of the strongest winds are occurring well removed from 91Ls estimated center, which is also consistent with subtropical cyclones. In fact, a ship report from roughly 350 miles to its east recently reported winds of up to 49 MPH in a thunderstorm.
Recon is tentatively scheduled to fly through Invest 91L later today.
Last edited by Betty; Jun 5, 2013 at 12:46 PM.
Reason: Giving credit
looks like a fun weekend from where I am sitting. The wind forecast is a little bit weird, as it shows nearshore winds around 10, but not far offshore to be 35+. So that's probably pushing the limits of forecasting accuracy, if I assume 10 offshore...