(Update Saturday 5-9-15 9:30 PM)
Tropical Storm Ana has formed and is at its peak strength right now. Getting the worst of it right now are the coasts of Northern South Carolina and Southern North Carolina (did I get that right :D ), or right around Wilmington, NC.
- Satellite / Radar Data Saturday Night
The National Hurricane Center is only issuing a forecast through Monday at 2PM, to where it will only hold any sort of tropical characteristic up through that time. After 2PM Monday, this storm poses little threat for anything other than ordinary thunderstorms and locally brief heavy rain.
- NHC Official Forecast
These two aspects, along with a cold front that also nears the region, confirms that Monday will be the day likeliest for storms in the Mid-Atlantic. Our Futurecast forecast shows scattered showers and possible thunderstorms over the region by 11AM Monday.
- Our Local Futurecast Forecast at 2PM Monday
(Previous Update from Tuesday)
We're still keeping a close eye on the disturbance along and east of Florida affecting the Bahamas. This system continues to have a chance for subtropical development over the next few days but as of now appears like it will have little to no affect on the D.C. area.
This area of showers and storms is associated with a surface and upper-level trough, meaning it doesn't have any tropical characteristics at the moment, but may become subtropical over the next few days.
The National Hurricane Center is monitoring the area for later in the week, and as of Tuesday has a 40% chance for development. For the latest Special Tropical Weather Outlook, the NHC has stated,
A large area of disorganized showers and thunderstorms extending
from the northwestern Caribbean Sea across Cuba, southern Florida,
and the Bahamas is associated with an upper-level trough and a weak
surface trough. An area of low pressure is expected to form in
association with this disturbance during the next day or two. The
low could gradually acquire subtropical characteristics over the
next few days while it moves generally northward at a slow forward
speed. For additional information on this system, see High Seas
Forecasts issued by the National Weather Service. The next Special
Tropical Weather Outlook will be issued on this system by 11 AM EDT
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...40 percent
Find more on the difference between a tropical, subtropical and extratropical storm here.
- Atlantic 5-Day Graphical Tropical Weather Outlook (Courtesy: National Hurricane Center)
As of this morning, the majority of model guidance either keeps the system offshore along the southeast coast or drifts the low into South Carolina on Friday. All guidance as of now keeps the low well south of the D.C. area, but some tropical moisture still may filter its way into the Mid Atlantic byt early next week.
We'll continue to keep a close eye on it as these types of disturbances are notoriously difficult for a global model to accurately forecast. Be sure to stay tuned, especially if you are headed to the southeast beaches within the next week.