Oct 17, 2010: Chilly Start, Cold End To Week

Today was a mainly sunny yet rather mild day, with high temperatures ranging from the upper 60s inland and in Long Island/S CT to the lower 70s in the immediate NYC area. While this is warmer than the average, we have seen 80s in this time frame before, most notably in 2007, also when 90s were observed in early October. This week, however, will bring much cooler temperatures, as well as several snow potentials in the higher elevations of the Northeast.

Tomorrow’s Outlook:

Tomorrow will bring colder temperatures as a trough moves into the Northeast, though the models yesterday overestimated the intensity of the trough, a bias that they usually have. A WNW wind is expected during the day. I went slightly warmer than yesterday’s forecast, expecting upper 50s to lower 60s inland and lower to mid 60s in the immdiate NYC area. Long Island/S CT will have highs in the lower 60s.

Tuesday And Wednesday: Cloudy, Chilly, And Rainy

The cold front related with the trough will stall in the central/southern Mid Atlantic tomorrow night. A weak wave of low pressure will ride along the stalled front, moving through the central Mid Atlantic. The heaviest rain will fall in southern Pennsylvania into central New Jersey, where at least 1/2 inch of rain is expected. The area will see around 1/4 inch, with high temperatures in the lower to upper 50s. It may be cold enough that some snow could fall in NE PA and in the Catskills, but the question is if enough precipitation can reach these areas and if it will be cold enough for that to happen.

Tuesday night will bring drier conditions but mainly cloudy skies, while another storm starts to form along the stalled front. This storm will be further south than the first one, and will bring moderate rain to the central/southern Mid Atlantic on Wednesday. While the area is expected to be dry, an isolated shower south of NYC cannot be ruled out. High temperatures will be slightly warmer than those of Tuesdady.

Thursday – Saturday: Cold Spell Potential

On Thursday, an area of low pressure near the Great Lakes will bring through a cold front, with widespread showers for the area in the afternoon, which will end by the evening. A strong trough behind this cold front will drop into the region, with 850 mb temperatures potentially below zero degrees celsius. If this solution is to verify, some snow flakes would fall in the interior NE on Thursday evening/night, with lows dropping into the 30s for a lot of places. Friday would bring much colder temperatures with highs in the lower to mid 50s for most of the area, and on Friday night, just as the trough is about to exit, low temperatures have the potential of reaching the upper 20s to lower 30s inland according to the GFS model.

While there is still some uncertainty on what happens, for example the GGEM doesn’t show a trough as strong as the GFS and has it further north, but a strong trough is generally expected around this time frame, which could bring cold temperatures to the area. Stay tuned for more details on this time frame.

Longer Range: Warm Up, October 26-28 Storm?

After the trough exits, warm air will spread into the region, and unless a trough shown to be in southern Canada on the models doesn’t drop south, then according to the latest models, a much warmer pattern will take place for the central/eastern United States, with high temperatures potentially back into the 70s. The models are likely to change though, so there is still uncertainty.

The GFS model has been consistent in showing a storm around the 27th, tracking well to the north/west of the area and bringing potentially heavy rain. This potential will be tracked over the next few days, and will be discussed in more details if it remains on the models over the next few days.

One thought on “Oct 17, 2010: Chilly Start, Cold End To Week

Leave a Reply