Nov 2, 2012: Nor'easter Expected Next Week

Forecast Highlights:

As the NYC area enters its fifth day after the devastating hurricane Sandy, the weather pattern offers little improvement over the next week. A sustained cold pattern will continue for the next several days, with highs in the 40s and lows in the 20s to mid 30s becoming an issue for places without power and heating. Following the cold, a nor'easter is expected to affect the region next week with additional rain, wind and snow, although not nearly to the extent of Sandy. Click below to read the full post.

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The Upton National Weather Service has a Special Weather Statement with safety and health information following Sandy.



Tonight - Tuesday: Cold Pattern Expected

A trough will persist over the region for the next several days, keeping colder than average temperatures in place with widespread sub-freezing lows that will only worsen conditions for those without power and heating, especially with the current gas crisis going on across the area with many stations closed. 850 millibar temperatures will generally remain below zero degrees Celsius in this time frame, with highs generally in the mid 40s to low 50s expected from Saturday through Tuesday. Low temperatures will gradually trend colder; temperatures on Saturday and Sunday mornings will drop into the upper 20s to mid 30s away from NYC with upper 30s in NYC and the immediate coastal areas, although by Monday and Tuesday mornings temperatures will drop into the low to mid 20s inland and the mid 20s to low 30s for the rest of the area except for NYC and the immediate coast, which should be in the mid 30s for lows. Cooler high temperatures are expected on Monday and Tuesday as well, reaching the low to mid 40s inland and the mid to upper 40s for the rest of the area.


Wednesday - Thursday: Nor'easter Expected

Just a week after Sandy, coastal areas are already looking at more issues with an expected moderate intensity nor'easter next week that is likely to affect the coast with additional rain and wind, although not nearly to the extent of Sandy. A shortwave dropping into the Great Lakes region is likely to phase with another shortwave south of the region, with a coastal low developing and intensifying close to the Mid Atlantic coast. The set up is favorable for a phasing scenario and a coastal nor'easter, with ridging in the western US and Atlantic Canada.

With Thursday's update, the model guidance was spread out all over the place, although I went closer to the more amplified and further west solutions with a nor'easter potentially affecting the region. Today's model guidance trended closer to this scenario, with the ECM holding steady with a moderate intensity nor'easter affecting the region as the UKMET and GFS started supporting this solution as well. The CMC remains east of the area, although it has been trending west as well with its recent runs. While model performance is not always the same with every storm, the ECM is often more reliable than the GFS when the ECM is more amplified and further west and the GFS is more progressive and further east, and for tonight's forecast I am siding closer to the ECM, with a nor'easter affecting the area from the Mid Atlantic coast into New Jersey and New England with rain, wind and snow.

Should the nor'easter take the track that the recent model runs are suggesting, rain and wind will once again be issues for places that have been affected by Sandy, especially for coastal areas that have been hit the hardest with coastal flooding and strong winds. The forecast is still subject to change as there is still no high confidence regarding the exact timing, track and intensity of the storm, although the timing is currently expected to be between Wednesday afternoon and Thursday evening, and potential impacts for the eastern Mid Atlantic region, including the NYC area, include over 1 to possibly 2 inches of rain, as well as wind gusts above 40 mph especially for coastal areas. With enough cold air, the nor'easter will also likely produce a snowstorm for parts of the Northeast, and interior northwestern parts of the area may see frozen precipitation before changing over to rain. Fortunately, the wind direction is not expected to come out of the southeast straight into the entire coast as was the case with Sandy, and the intensity of the storm, including the wind gusts and storm surge, will be weaker than that of Sandy. Regardless of these differences, even a moderate nor'easter will have some impact on coastal areas devastated by Sandy. Stay tuned for more information over the next few days.

For more localized forecasts for the area, please refer to the 5-Day Forecast page. The forecast in the 5-day forecast page for the Wednesday-Thursday time frame is still subject to change over the next few days depending on the storm.


Longer Range: Relief is showing up beyond the mid week storm. As the storm exits, a strong trough will drop into the western US, with a strong ridge building in for the eastern half of the US resulting in dry and much warmer conditions, as temperatures potentially return into the 60s for highs. More information on the longer range will be posted with the next Pattern Outlook, scheduled for Sunday. Pattern Outlook #3 was originally supposed to be posted on October 21, but was postponed due to hurricane Sandy.