7AM EDT Update 4 August 2020
Last night hurricane Isaias, aided by shear in this instance, rapidly strengthened before landfall in North Carolina. Areas near and to the right of the center saw the worst, including 4-5 feet of Storm Surge, damaging winds were widespread, and there has been lots of flooding and power outages throughout the area. In the town of Ocean Isle, where it made landfall, it also sparked and fanned multiple house fires. It continues into Virginia this morning. 370000 power outages in North Carolina at this time, and 185000 so far in Virginia.

The right front quadrant of Isaias has been by far the most powerful and damaging of the areas, but the rain has wrapped around to more of the west side since just before landfall. The right front Quadrant will effect SE Virginia, Eastern Maryland and Delaware, New Jersey, Manhattan and Long Island, parts of CT, MA, VT, and Western NH and eastern Quebec.

5PM EDT Update 2 August 2020
Tropical Storm Isaias has strengthened a bit, Enough for Hurricane Watches from Santee River, SC to Surf City, NC and now tropical storm watches extend all the way up the east coast to Rhode Island. Isaias has around 32 hours over water before landfall around 2am Tuesday, enough to potentially restrengthen before landfall to a hurricane, shear conditions improve for it once the system is north of Jacksonville, FL. Those in North Carolina, particularly at and just east of the landfall point, should prepare for potential hurricane impacts, as it may reach hurricane strength before landfall. Listen to local media and officials for more information.

The system has managed to stay offshore of Florida enough for the majority of the bad weather to remain offshore, with Florida only receiving a few rain bands today.

Other than 94L, which chances are dropping it develops, there are no other likely areas this week, but things could change into the historical peak of the season (Which just starts ramping up on Aug 15, peaking September 15th) for more.

8AM EDT Update 2 August 2020
The Hurricane Warnings along the coast have been replaced with Tropical Storm Warnings, Isaias is no longer forecast to regain strength after its last realistic chance to restrengthen has passed. With the system as sheared as it is on the west side, effects in Florida will be limited to a few bands coming ashore (which may be the worst part for many) and some minor surge and a little bit worse weather right along the coast. If another blowup occurs, the rainfall near where it happens will be extremely heavy, but this is mostly for those immediately on the track itself.

Further up the coast, The Tropical Storm Warning has been extended northward along the southeast United States coast to South Santee River South Carolina.

A Storm Surge Watch has been issued from Edisto Beach South Carolina northward to Cape Fear North Carolina.

And the Tropical Storm Watch has been extended northward to Surf City, North Carolina.

Those east of the landfall point in North Carolina will likely get the heaviest rains outside of the Bahamas.

5PM EDT Update 31 July 2020

Track shifts west on Isaias, Florida under warnings. Tropical Depression 10 develops off Africa.

A Hurricane Warning is in effect for the east coast of Florida from Boca Raton to the Volusia/Brevard County Line.

A Hurricane Watch is in effect from the Volusia/Brevard County Line to the Flagler/Volusia County Line and from south of Boca Raton to Hallendale Beach.

A Storm Surge Watch is in effect for the east coast of Florida from Jupiter Inlet to Ponte Vedre Beach.

A Tropical Storm Watch is in effect from the Flagler/Volusia County Line to Ponte Vedre Beach.

Additionally TD#10 in the east Atlantic dissipated before gaining a name.

11AM EDT Update 31 July 2020
Hurricane Watches are now up for Florida, from north of Deerfield Beach northward to the Volusia-Brevard County Line. A Tropical Storm Warning has been issued for portions of the Florida east coast from north of Ocean Reef northward to Sebastian Inlet and for Lake Okeechobee.

Winds have dropped to 75mph, but movement is to the west northwest. At the closest approach to Florida, the forecast windspeed is 85mph. 90mph while closer to the Bahamas.

6AM Update 31 July 2020

Isaias became a hurricane overnight when recon found 80mph winds at the surface, it remains there this morning. The future track is still a bit uncertain as it has only recently recovered from the crossing of the island of Hispaniola.

The biggest change overnight because of the hurricane upgrade that this forced hurricane warnings for all of the Bahamas. The system will come very close to Florida, and this likely will cause additional tropical storm or hurricane watches/warnings for more parts of the coast later today.

The west side of systems tend to be weaker (not always, however) coming from this direction, so the further east Isaias remains offshore the better. The same general idea of the forecast seems ok now, but any shift west would bring the east coast of Florida closer to the bad conditions. Shear is expected to possibly weaken the system as it gets closer to Florida, so that may keep things in check. The major difference between the models seems to be how quickly or not the system moves by, with the GFS side moving fast, while the Euro side slows it down more. This is the difference of Sunday morning for the GFS suite to be closest to Florida, or Monday morning for the European Suite. So there remains some degree of uncertainty in the future there. The official forecast currently favors Sunday morning for the closest Florida approach.4

The possibility that the storm effects parts of the coast from Florida all the way to New England does exist, so folks north of there, Particularly in eastern North Carolina, but also Long island to Cape Cod, and potentially Maine/Nova Scotia, should probably watch the progress on this system as well. (Anywhere in the cone)

11PM Update 30 July 2020
Recon finds winds of 80mph in now Hurricane Isaias, a special advisory will soon be issued.

5PM Update 30 July 2020
Isaias is now near the north central section of the Dominican Republic and about to reenter the water fairly soon, it is moving rapidly NW or WNW at 20MPH currently. Tropical Storm watches are now up for Florida from Ocean Reef northward to Sebastian Inlet.

A hurricane is now forecast to develop near Andros island on the Bahmas, and it may impact the coast of North Carolina on Monday.

The Tropical Storm Warnings for the central and northwest Bahamas may be upgraded to Hurricane Warnings this evening or tonight.

9AM Update 30 July 2020

Isaias is approaching the Dominican republic and a lot of question remains around what will happen to the system after it passes, models are split between Florida and no Florida impacts and it will be difficult to determine until the system is a bit past the island of Hispaniola and we find where the new center settles.

93L is also being tracked in the far east Atlantic, with a 20% chance for development.

11PM Update 29 July 2020
PTC 9 is finally Tropical Storm Isaias. Forming Southwest of the earlier 8PM point at 15.8N 67.0W but moving west northwest overall.

The government of the Bahamas has upgraded the Tropical Storm Watch for the Central Bahamas to a Tropical Storm Warning and has issued a Tropical Storm Watch for the Northwestern Bahamas. Watches for Portions of Florida may be issued tomorrow.

July 29th, is the earliest an Atlantic "I" storm has formed since naming storms started, Irene in 2005 formed on August 4th, which was the prior record holder.

Usually systems that pass over the very tall mountains of Hispaniola get torn up, but since Isaias has such a broad wind field, the weakening will probably not be as significant as usual. This could mean more center reformations may occur.

Therefore it is unlikely to have a clear picture of what the US land impacts may be until Isaias is north of the Caribbean islands.

11PM Update 28 July 2020
PTC 9's center relocated a bit south and west of earlier, shifting the track west. It's now forecast to cross PR and parts of the Dominican Republic, it still may form into a Tropical Storm tomorrow as there is enough convection to do that, but countered by the fact its booking WNW at 25mph.

Land interaction with Hispaniola will impact it but the speed it's moving and the disorganization may make the impact less than typical for a well organized system. The best conditions for development would be after it cross Hispaniola and moves south of the Bahamas.

The models will likely contiinue to have a difficult time handling this system, particularly on the intensity side as the NHC calls out the fact that GFS-and ECMWF-based SHIPS intensity guidance shows considerable southwesterly shear, when north of Hispaniola, however it winds up being self induced outflow issues due to the sheer size of the system, therefore the intensity estimates may be on the low side closer to Florida. .

It is worth watching anywhere in the watch warning area or cone or just outside it. The Bahamas has issued a Tropical Storm Watch for the Turks and Caicos Islands for this system.

Original Update

Advisories have begun on Potential Tropical Cyclone 9, formerly Invest 92L in order to enable watches to be issued for some of the islands.

Tropical Storm Warnings have been issued for:
Puerto Rico, Barbuda, Virgin Islands, Montserrat, St. Kitts, Nevis, Guadeloupe, Martinique, St. Martin, Saba, St. Eustatius

Recon is scheduled to check it out later today, and an upgrade may occur then... if a closed, well defined low-level circulation exists..

The current NHC Forecast (granted with a lot of uncertainty in both track and intensity) shows a potential threat to the Bahamas and Florida. The final forecast point is inland near West Palm beach with 60mph winds.

*** It cannot be stressed enough that since the system is still in the formative stage, greater than average uncertainty exists regarding both the short-term and longer-term track and intensity forecasts. ***

It should be noted that a stronger cyclone is likely to favor a more northern track, while a weaker system is likely to remain more equatorward. Folks should remember that the long-term average NHC track forecast errors at days 4 and 5 are 140 and 175 n mi, respectively.

See the forecast lounge for model discussion and what ifs.

{{NCCoastMedia}}

{{EastFloridaRadar}}

{{MidAtlanticRadar}}

{{StormLinks|Isaias|09|9|2020|9|Isaias}}

{{StormLinks|10|10|10|2020|10|Tropical Depression Ten}}

{{StormLinks|94L|94|11|2020|94|Invest 94L}}