Tropical Storm Joaquin Forms, Threat to Northeast Coast Increasing

Satellite pictures during the evening shows that Tropical Depression 11 is becoming better organized and is now Tropical Storm Joaquin. Thunderstorms have formed near the circulation center as Tropical Storm Joaquin moves southwest into an area of lighter wind shear. Conditions are favorable for additional strengthening tonight and Tuesday.

...DEPRESSION STRENGTHENS TO TROPICAL STORM JOAQUIN...
...THE TENTH NAMED STORM OF THE SEASON...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...26.7N 70.4W
ABOUT 400 MI...645 KM NE OF THE CENTRAL BAHAMAS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...SW OR 230 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES

 


http://www.ssd.noaa.gov/goes/east/eaus/vis-animated.gif

 

http://www.ssd.noaa.gov/goes/east/carb/vis-animated.gif

The southwest movement is important because this shifts the track further west overall and it is becoming more apparent that Tropical Storm Joaquin will become a player along the east coast late this week and this weekend. The key to all of this is the deep upper trough that forms in the Tennessee Valley which creates a strong southerly flow along the east coast. The latest National Hurricane Center forecast tracks reflects this upper air pattern which will drive the storm northward. We will of course examine other models in the morning to see how this all plays out.

nhcprog

 

With regards to timing this will be for late in the week and into the weekend. In the meantime the first player arrives on the scene tomorrow night and Wednesday with heavy rains that will produce 1 to 2 inches in many locations for the first shot. High pressure builds across Northern New England and Eastern Canada which will set up a strong onshore flow for Thursday and Friday.

We continue to watch this system as it becomes a player with all the action that is going on along the east coast. There are several pieces regarding the setup here. The latest one Monday afternoon focuses on the European model which shows a very robust tropical system and a pretty extreme but interesting solution late this week and into the weekend.

Back a number of weeks ago I wrote a piece about what you need to get a tropical system to move up the east coast. You can read that for background but this is what the upper air is supposed to look like by the end of the week.

Again I am more interested here in how much moisture we can get out of this as the front and trough eventually absorb the tropical depression. Complicating all this even further is strong high pressure to the north that will create a very strong onshore flow later in the week. Needless to say much to watch and sort out in the coming days.

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