Oct 31, 2010: Tracking Strong Storm Potential

Notes:

- The 5-Day Forecast was updated for most of the area tonight. In addition, NYC Area Weather has a Freeze Warning in effect for most of the area tonight.

- Reminder: The polls for the potential winter temperatures and snowfall (top right, below the radar loop) will remain open until November 27. At this time, there are 5 votes, which favor average temperatures and snowfall.

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Today was a partly cloudy day across the area, with high temperatures in the lower 50s inland, and in the upper 50s to lower 60s for the rest of the area. The cold front that moved through earlier today also brought widespread snow showers for the Northeast, with moderate snow accumulating up to 1-2" in central Maine. As the strong trough moves into the region, temperatures will significantly cool down, with below freezing temperatures expected for a good part of the area tonight and tomorrow night.

Tonight/Tomorrow's Outlook:

Tonight will be the coldest night so far for a lot of places, with widespread frost expected. Low temperatures will be in the mid to upper 20s inland, upper 20s to mid 30s north and west of NYC and in southern Connecticut, lower to mid 30s in Long Island, and mid to upper 30s in NYC. A freeze warning is in effect for most of the area tonight.

Tomorrow will be a mostly sunny and chilly day. High temperatures will only be in the mid to upper 40s inland, and the upper 40s to lower 50s for the rest of the area. A NNW wind is expected during the day.

Tuesday And Wednesday: Staying Cold, Dry

Monday night will likely be the coldest night of this cold spell, with low temperatures in the mid 20s inland, mid 20s to lower 30s north and west of NYC and in S CT, upper 20s to lower 30s in Long Island, and in the mid to upper 30s for NYC. Tuesday will be slightly warmer than Monday, with Wednesday slightly warmer. Tuesday night will still be cold but with temperatures slightly warmer.

Late Week Storm: Update On The Potential Scenarios

Yesterday, I mentioned how there were large differences with the models, especially with the GFS, ECMWF, and the GGEM. I mentioned in my 5-Day Forecast that rain is likely for Thursday, but with not much detail on which solution. After looking at the latest models today, the trends, and the expected pattern, however, I am leaning towards an inland storm track that was suggested by the GGEM yesterday.

The GFS model has not been consistent with this time frame from the start, for example the trough expected to drop into the Midwest was at first shown to be so far east that it would barely even affect Maine. With each run, the storm kept trending more and more west, and it is also trending slower as well, with the last few runs taking large steps towards the GGEM and ECMWF. The GGEM and ECM have some differences, such as how far the storm ends up inland, but both show the main idea that the storm is likely to track slightly inland of the coast, and bring heavy rainfall and mild temperatures to the Mid Atlantic and New England, with several inches of rain possible.

There are still a lot of differences including phasing of the storm, and the forecast could change over the next few days, but it is becoming more likely that this storm could take an inland track, bringing high temperatures into the upper 50s and 60s for parts of the area, with potential impacts ranging from several inches of rain and strong winds in the eastern side of the storm to potential snowfall on the western side of the storm, which could be anywhere from the Northeast to the Ohio Valley/Great Lakes.

The GFS model is trending towards the ECM/GGEM but is not quite there yet, quickly taking the storm out by Friday, but given its progressive bias, and the fact that it is trending slower, I am leaning towards something closer to the ECM/GGEM. This solution, however, is not final yet, and is based on the latest trends and potential trends over the next few days. Stay tuned for more details on this storm over the next few days.


Hurricane Tomas: Soon-To-Be Tropical Storm


As expected, Tomas strengthened to a Category 2 hurricane last night, and encountered stronger shear today. This shear, however, had a stronger effect on Tomas than expected, and it is now barely a Category 1 hurricane, likely to be downgraded to a tropical storm later tonight. Tomas has lost a lot of its convection and is much more disorganized due to this shear, which is expected to continue affecting Tomas for the short term.

By Tuesday/Wednesday, however, shear is expected to weaken while the steering currents collapse, with Tomas starting to drift north likely towards Hispaniola, and Tomas will likely strengthen again, potentially rapidly if the environment is favorable enough, and may return to Category 2 intensity before making landfall in the Caribbean islands, likely somewhere between Jamaica and the Dominican Republic. Tomas has the potential of being a dangerous hurricane, and the Caribbean islands from Cuba to Puerto Rico, especially Haiti, should closely follow Tomas.