Tropics

Tropical Storm Arthur, Heat & T-Storms Wed. & Thurs.

Miguel Pierre Severe Wx, Tropics

First tropical storm of the Atlantic Hurricane Season, Arthur was born today, from a disturbance that was previously discussed off the Southeast US coast.  Weaker northerly shear allowed thunderstorms organized more over the center. As of the 11pm advisory from the National Hurricane Center, Arthur has maximum sustained winds of 50mph and is pm;u drifting northward. However, very cold cloud tops near the center, seen on satellite imagery this evening, indicate that Arthur continues to get better organized and might start intensification trend soon.

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Most model guidance shows Arthur strengthening to a hurricane as it moves north-northeast near or over the outer banks of North Carolina. That area could some heavy rain and strong winds. Although, since this is lop-sided system with drier air to northwest, hurricane force wind will likely be in southeast quadrant. Then the storm will track out into the open Atlantic, well southeast of the Tri-State Area. However, Arthur will be in  right-entrance region of strong upper-level jet streak, enhancing an band of rainfall over local tri-state area during day on Friday (July 4th). Some rough surf may occur at the beaches. The rain start moving out by Friday evening. Perhaps just in time for fireworks festivities. This weekend is look beautiful with mostly sunny skies and temperatures in middle to upper 80s.

Before that we are looking at more heat and humidity to continue through at Wednesday for tri-state area. High temperatures on Wednesday will likely get between in low or middle 90s for NE NJ and NYC, with sea-breezes keeping more coastal areas slightly cooler. There is also a chance of some  afternoon thunderstorms, with a pre-frontal trough over region. Some thunderstorms may be locally severe with amount of surface-based instability shown of the guidance. However, bulk shear is little low for thunderstorms to remain well organized. So I’m not expecting widespread severe weather. Some thunderstorms may also produce some very heavy rainfall. Thursday looks wetter with cold front and upper-level streak closer,with  scattered showers and thunderstorms all day. Some thunderstorms may train and cause flash flooding.

 

First Atlantic Tropical Storm Possible off the Southeast US

Miguel Pierre Tropics , , ,

The National Hurricane Center is watching a disturbance of the SE coast of the United States, to become first tropical storm of Atlantic Hurricane Season. Their latest tropical weather outlook at 2pm Sunday, gives a 60% chance of tropical storm formation over next 48hrs. If it becomes a tropical storm, it will be named Arthur:

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Currently this disturbance has a broad low-level center, with northerly shear displacing convection to the south and east of center. The shear is being caused by an deep upper-level trough over Western Atlantic. This trough will be replaced an upper-level ridge early this week. Which will result in a more favorable upper-level environment for further organization, as the disturbance tracks slowly south or southwest over over next few days.  Then later in the week,  this storm will begin track northeast, ahead of next trough and cold front approaching from the west.  For the New York Tri-state area, the model consensus at this time, keeps this storm far enough offshore, that any impacts would be very minimal for the July 4th holiday weekend. Some rough surf, at the beaches. But not much else. If the cold front and trough is slower and deeper, this may allow the storm to track closer to our area. However, this scenario is unlikely with no high-latitude blocking. Stay tuned for more blog updates on any new developments with this disturbance this week.