1. Tropical storm force winds that could cause tree damage and power outages will continue to spread across New England tonight.

2. Heavy rainfall near the path of Isaias, through the Hudson River Valley, is likely to result in flash flooding, particularly through urban areas and the surrounding terrain of the Catskills, Adirondack and Green Mountain Ranges through Tuesday night. Scattered minor to moderate river flooding is likely across portions of the Mid-Atlantic. Quick-responding rivers in the Northeast will also be susceptible to minor and possible moderate river flooding.

3. The threat of tornadoes will spread into New England this afternoon and evening.

CHANGES WITH THIS ADVISORY:

The Tropical Storm Warning has been discontinued west of Watch Hill, Rhode Island, including Long Island and Long Island Sound.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
- Watch Hill Rhode Island to Stonington Maine
- Martha's Vineyard, Nantucket, and Block Island

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 6 to 12 hours.

For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office.

Key messages for Isaias can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT4.shtml.

WIND: Widespread tropicalstorm conditions are expected tonight in the tropical storm warning area in southern New England. These winds could cause significant tree damage and power outages.

Galeforce winds are expected to spread into southeastern Quebec tonight and Wednesday. See products issued by Environment Canada for more information.

RAINFALL: Rainfall accumulations of 1 to 3 inches are expected along and near the track of Isaias across northeast New York, northern Vermont, northern New Hampshire, and Southern Quebec.

Heavy rainfall near the path of Isaias could result in flash flooding, particularly through urban areas and the surrounding terrain of the Adirondack and Green Mountain Ranges through tonight. Scattered minor to moderate and isolated major river flooding is ongoing or forecast across portions of the MidAtlantic. Quickresponding rivers in the Northeast will also be susceptible to minor and possible moderate river flooding.

TORNADOES: A couple of tornadoes are possible across southern New England through this evening.

SURF: Swells generated by Isaias will spread northward along the midAtlantic and Northeast coasts of the United States through tonight. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

At 800 PM EDT (0000 UTC), the center of Tropical Storm Isaias was located by NOAA Doppler weather radars and surface observations near latitude 43.6 North, longitude 73.0 West. Isaias is moving toward the northnortheast near 40 mph (65 km/h), and this general motion is expected through tonight. On the forecast track, the center of Isaias will continue to move farther inland over eastern New York and Vermont this afternoon and evening, and over southern Canada tonight.

Data from Doppler weather radars along with surface observations indicate that maximum sustained winds have decreased to near 50 mph (80 km/h) with higher gusts. Continued weakening is expected this evening, and Isaias is forecast to become posttropical tonight or early Wednesday.

Tropicalstormforce winds extend outward up to 205 miles (335 km) from the center. During the past few hours, there have been numerous reports of wind gusts of 4050 mph (6580 km/h) across portions of Rhode Island, eastern Massachusetts, and southeastern New Hampshire.

The estimated minimum central pressure based on surface observations is 997 mb (29.44 inches).

NOAA Doppler radar data from Islip, New York (KOKX), indicated 70-kt winds just off the surface south of Long Island earlier this afternoon, along with buoy reports from New York Harbor Inlet (44065) that supported lowering the intensity to 55 kt, so that value is used for this advisory.

The motion remains north-northeastward or 020/35 kt. Isaias will continue moving north-northeastward through tonight, accompanied by a gradual decrease in forward speed. In 12 hours or, the cyclone is expected to interact with a larger extratropical over southeastern Canada and degenerate into a post-tropical cyclone near western Maine. By 24 hours, Isaias is expected to transition to an extratropical low, and dissipate or become absorbed by the aforementioned larger extratropical low. The new NHC track forecast is just an extension of the previous advisory, and lies very close to the tightly clustered consensus track models.

Isaias will continue to gradually spin down and lose its tropical characteristics. The precipitation has decreased in size and also has become more stratiform in appearance, which are indications that the cyclone is gradually weakening. This downward trend should continue until Isais becomes an extratropical low in 12-24 hours.

There also remains a risk of tornadoes across portions of New England this afternoon and evening