Mar 13, 2013: Colder Pattern Begins

Forecast Highlights:

Today was the last day of the temporary warm up with highs again in the 40s to low 50s across the area. Following scattered showers this evening, drier conditions will return for Thursday and Friday as a strong trough moves through the region, with temperatures moderately colder than average on both days. With the current pattern in place, no warm pattern is in sight for a while, with several storms expected to affect the region during this time period as well, one of them next Tuesday.

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Today's Observations:

Temperatures slightly cooled down compared to Tuesday following the cold front, with drier conditions observed aside from scattered showers in parts of the area in evening. Temperatures were slightly cooler but still slightly warmer than average, peaking in the low 50s across most of the area except for eastern Long Island and interior NW areas. The warmest temperature was 53 degrees in Newark and JFK.


Tonight - Monday: Colder Than Average

As previously mentioned, a strong trough is entering the region, with widespread colder temperatures expected. Partly sunny skies are expected on Thursday with highs only in the low to mid 30s inland and mid to upper 30s for the rest of the area; the average high temperature for 3/14 in Central Park is 49 degrees, with temperatures at least 10-15 degrees colder than average expected. A breezy NW wind of 10-20 mph is expected, locally higher in Long Island, with wind chills in the 20s across the area throughout the day.

The coldest temperatures are expected on Thursday night, dropping into the upper 10s to low 20s inland and the low to mid 20s for the rest of the area, with upper 20s towards NYC and parts of Long Island. Decreasing NW winds are expected overnight, with mostly sunny skies on Friday and highs slightly warmer but still below average, reaching the upper 30s to low 40s across the area, approaching 45 degrees in the immediate NYC area.

Showers are expected to spread into the region on Saturday morning, falling in the form of snow in northern parts of the area. The latest trends have been for a drier storm with precipitation lighter and more spread out; scattered showers, mixing with snow further north, are expected throughout the day, although with this trend it is increasingly likely parts of the area may fail to see precipitation. Highs are expected to reach the mid to upper 30s inland and upper 30s to low 40s for the rest of the area. Drier conditions are expected overnight into Sunday with clearing skies and highs in the upper 30s to low 40s inland and low to mid 40s for the rest of the area for Sunday and Monday, with showers possibly developing late on Monday.


Tuesday - Beyond: Rain/Snow, Then More Cold

The next storm is expected to affect the region on Tuesday. Despite the continued strong ridging over Greenland, this is currently modeled to track well north of the region; an upper level low is expected to retrograde west through central Canada, with rising heights downstream ahead of the approaching shortwave, which on the current models fails to dig south of the northern US, then continuing to track northeast through the Great Lakes and Canada as a secondary low forms over the Northeast region. Such a scenario would result in rain and briefly mild temperatures for the area, with snow to rain in the Northeast.

This is still nearly a week away, and as the last few storms have shown, model agreements especially this far out can easily change; for example, with the early March storm, the models agreed in the medium range on a storm staying almost entirely south of the region; the coastal low was mainly south of the area, but the models missed the inverted trough feature that produced heavy snow in the region. With the February 24 storm, the models in the medium range agreed on a significant storm with heavy rain in the area and heavy snow in Massachusetts, while the storm ended up weaker, further southeast and much drier than modeled, with only light rain falling in the area. The aforementioned pattern with the lack of significant digging works against this tracking far south enough for a plain snowstorm in the area, although the potential is still there for a snowstorm in the Northeast US and perhaps parts of the area as well should the storm end up colder and more south than currently modeled. Stay tuned for more information on this storm as details become clearer.

Behind this storm, colder than average temperatures are expected to continue, with high temperatures still likely in the 40s. Uncertainty increases towards the longer range with the ECM showing cold and dry conditions while the GFS and CMC continue an active stormy pattern. This time frame is still uncertain and also depends on what happens with the Tuesday storm, although the next possibility for a storm appears to be towards Friday or possibly next weekend. The overall theme of temperatures generally near to below average continues, however; based on the latest indications this pattern looks to persist towards the end of March, potentially into early April as well with only a few brief periods of warmer temperatures in between. More information will be posted on the long range over the next few days.