Sept 4, 2012: Chilly Temperatures Next Week?

Forecast Highlights:

- Significant rain forecast busts - some rain tonight, tomorrow
- Strong cold front to produce storms on Sunday, keep Leslie offshore
- Chilly temperatures possible early next week

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Monday, September 3


Detailed observations coming soon (updated 10/7/12)


Tuesday, September 4

Detailed observations coming soon (updated 10/7/12)



Tonight - Friday: Still Warm, Humid, Some Rain

The forecast originally called for a widespread heavy rain event with widespread 1-2+ inches of rain, which was still conservative compared to other models supporting a more widespread axis of 3+ inches of rain. While amounts have already exceeded 1-2 inches locally, especially in central Long Island, parts of southern CT, and most notably in southern NJ where several inches of rain were observed this morning, widespread 1-2+ inches are no longer expected across the region from the rain event, which as the latest radar posted to the left shows is not enough to support widespread heavy region-wide rainfall.

The latest forecast is for additional scattered storms especially north/west of NYC tonight, some of them locally heavy/strong, with additional scattered storms during the day on Wednesday. Additional rain totals generally between 1/4 and 1/2 inch are expected, locally higher/lower.

As the remnant moisture from Isaac moves out, much warmer temperatures will briefly return for Thursday and Friday, with widespread highs in the mid to upper 80s expected from NYC and further north/west, perhaps reaching 90 degrees in parts of the immediate NYC area, with slightly cooler temperatures further east due to onshore winds. Humid conditions are expected to continue, resulting in slightly higher heat index values. There is a risk of isolated storms on both days, especially on Friday.


Weekend - Next Week: Rain, Then Perhaps Much Cooler

A relatively strong trough and cold front for this time of the year will move through the region on Saturday into Saturday night, producing widespread showers and thunderstorms. While there is still uncertainty with the exact timing and location, the potential is there for severe weather associated with the cold front. With the strong cold front moving through the region, Tropical Storm Leslie, which will likely be a hurricane by that time, will be kept offshore, while potentially strengthening into a major extratropical cyclone as it strikes Atlantic Canada. There is still some uncertainty with exactly how this setup plays out, regarding the cold front and how Leslie interacts with the trough, although there is an increasing likelihood of a relatively strong cool air mass dropping into the region, bringing a few days of much cooler temperatures. Should the aforementioned scenario with Leslie and the cold front verify, which is gaining model support, high temperatures would drop into the 70s and perhaps even some 60s along with sunshine, along with more widespread overnight lows in the 40s possible. Stay tuned for more information on the weekend and early next week outlook.