Good morning everyone, We are monitoring the potential for a tropical cyclone developing which should track north along the coast or remain just offshore. The NHC has increased the chance of formation to 80%. Regardless of its development, *the main concern with this system in southern New England will be the potential for flash flooding from heavy rainfall Friday into Saturday, especially in more urbanized areas. *The only substantial change with this email is to add the mention for an isolated severe thunderstorm which may spawn a tornado or two. Here are the key points: *Track/Strength Uncertainty: High* It is unknown how the system will develop and where it will eventually track. This will have a big impact on who sees the heaviest rainfall. *Main Threats:* *Flash Flooding:* We are most confident in the potential for heavy rainfall Friday night into Saturday morning. Rainfall of 1 to 2 inches is likely with locally higher amounts. Minor urban flooding is likely but more significant urban and small stream flooding is possible depending on where the heaviest rain falls, which is unknown at this time. *Severe/Tornado:* There is the threat for an isolated severe thunderstorm, and with that a tornado or two is possible. *Wind:* We are less confident in wind impacts due to high uncertainty as to how the system develops and eventually tracks. It’s quite possible stronger wind gusts (more than 30-40 mph) remain offshore southeast of Cape Cod and the Islands or don’t materialize at all. Prevailing direction of any of the stronger wind gusts should be from the south or southeast. *Seas:* We are also less confident in how much seas will build given uncertainty in the wind forecast. Highest seas approaching 10 feet may affect waters south and east of Cape Cod and the Islands. *Coastal Flooding:* We are highly confident that the threat is low on both coasts as tides are relatively low through the weekend. *Rip Currents:* We have low confidence due to uncertainty in the wind forecast, but there is the potential for moderate rip currents Friday and Saturday, possibly into Sunday, mainly at the south coastal beaches. Thanks, Bryce Williams and Hayden Frank If you have any questions or would like more information, don't hesitate to contact us via this email address, on NWSChat <https://nwschat.weather.gov/>, or at the following: National Weather Service Boston/Norton, MA 46 Commerce Way Norton, MA 02766 508.622.3280 Website <http://www.weather.gov/boston> | Facebook <http://www.facebook.com/NWSBoston> | Twitter <http://www.twitter.com/NWSBoston>