Saturday 1 PM EDT
Sandy is still wobbling northward well off the South Atlantic coast. As a strong trough aloft approaches Sandy, the storm's circulation will be drawn into and become part of a greatly expanded upper air storm.
Since the storm will be a hybrid that includes some of the characteristics of the non tropical storms that cause most the cold season precipitation we see in the Great Lakes and Northeast, its circulation will be more spread out (rather than more compact). A lot of rain will be generated as tropically moist air is forced westward over air that is much cooler. This is something we typically do not see with pure tropical storms/hurricanes.
What all this means is that the heavy rain and increasing wind will reach places long before the center arrives. Delaware, New Jersey, as well as parts of eastern Pennsylvania and Maryland, are likely to start getting damaging winds and torrential rain tomorrow night, perhaps escalating into the worst conditions Monday morning. The center will come ashore after this, and by that time the rain and even the wind will be weakening.
Unless the storm tracks farther north than expected, the New York City area may be near the northern edge of the very worst conditions. Where the wind and rain are the worst, there will be streets flooded with water and massive tree damage and power outages. And, the wires have to be restrung one at a time... that's what takes so long (as well as other challenges of accessibility and maintaining safety.
It is important to complete your planning and preparation before the worst conditions approach later tomorrow. This video shows the situation and forecast as of early Saturday afternoon. Please check more recent information that will be continuously updated on AccuWeather.com. Also, your local emergency management people are trained on helping people avoid and deal with the most critical things that can kill and destroy.
Enhanced infrared satellite picture from early Saturday afternoon.
It's going to be hot hazy and humid in the much of the Northeast today through Thursday. The recalescent, sudorific, canicular, pyrogenic frying heat gains our attention.
A line of persistent showers and thunderstorms stretched from Long Island Sound to Cape Cod. Some areas in this zone had more than 3 inches of rain this morning, and there can be highway flooding in localized heavy showers this afternoon and evening. This radar shows the rain zone just after 10 a.m. ET.
This map shows the predicted upper-air flow for tomorrow night. Our timing estimates suggest showers and some thunderstorms could affect the I-95 corridor from Portland and Boston to New York City (and perhaps Philadelphia) on Sunday.
For the start of this "Olympics of the Forest," the weather looks good, as forest we can tell. From DC to NYC, it looks sunny for at least the next two, tree days.
As moisture from former hurricane Delores moved northward, the dynamic changed, and thunderstorms broke out. This map shows the more than 300,000 strokes that occurred between early yesterday and early today.
The recent volatility of the weather in many areas of the Central and Eastern states is demonstrated by the widespread thunderstorm activity of the last couple of days. The lightning map shows hundreds of thousands of lightning strokes between 7 a.m. ET yesterday and about the same time today: