Monday, August 22, 2016 3:39 AM

Firsthand Weather Tropical Update

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Tropical Depression Fiona, currently about 543 nm northeast of the Leeward Islands is still working her way east while 2 Tropical waves  look like they have the potential to develop over the coming week give Firsthand Weather plenty to watch in the Atlantic.

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Water temperatures in the Atlantic are very warm ahead of these systems with temperatures in the low to mid 80’s spanning the coast from Florida up towards Virginia Beach.  These warm waters extend well out into the Atlantic along the Gulf Stream, which is bringing water as high as the upper 70’s along the New Jersey and Long Island New York coastlines.  The drop off to colder waters, around the low 70’s, doesn’t really happen until you get up to around Massachusetts, where the Gulf Stream moves further off shore, but water temperatures above 82 degrees exist not too far South from New England, which could help prevent a storm from weakening too much as it heads North.

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Tropical Depression Fiona

Fiona has weakened into a Tropical Depression today as deep convection continues to sputter near her center.  Each successive burst has been a little smaller and less organized than the
previous ones that sheared off in the strong westerly upper-level winds.  Given that earlier scatterometer data only showed a few 40 mph winds, the decrease in convective organization since that time leaves maximum sustained winds at 35 mph.  Fiona continues to weaken at this hour due to 35 mph wind shear from the west and mid-level dry air impacting the system.  Fiona may devolve  into a remnant low in the next day or two but additional strengthening is expected after that as the wind shear is expected to greatly weaken as the atmosphere moistens to the west.  If Fiona manages to maintain her tropical characteristics during this time period, it is possible that she could once again become a tropical storm near the end of the week as she passes to the Southeast of Bermuda.

Tropical Depression Fiona

Tropical Waves

In the Central Atlantic, a tropical wave is pushing west toward the Lesser Antilles.  This system is producing limited and disorganized showers and thunderstorms as dry air near the system continues to inhibit the waves development.  Environmental conditions are expected to be come more conducive for development as the wave approached Hispaniola and the Southern and Central Bahamas later this week.

Another tropical wave is located about 300 miles South of the Cape Verde Islands.  This wave is continues to show signs of development and is forecast to become a Tropical Depression in the next couple of days.  Environmental conditions will remain favorable for the next several days as this system moves West over the Eastern Tropical Atlantic.