Jan 12, 2013: Mild This Week, Then Much Colder

Forecast Highlights:

With cloudy skies and widespread fog across the area, temperatures ended up colder than expected, peaking in the low to mid 40s in NW NJ/SE NY and the mid to upper 40s for the rest of the area. Overnight lows, however, will remain very mild, in the 40s tonight and even some 50s on Sunday night, which is warmer than the average highs.

Fog will continue tonight and tomorrow, with the warmest temperatures peaking on Monday morning ahead of a frontal passage. Scattered rain and snow showers are expected on Tuesday and Wednesday, although mostly staying south of the area. Temperatures will mostly remain slightly warmer than average through next weekend and early the following week, but will not remain mild for long.

Tonight – Monday: Cloudy, Fog, Mild Conditions Continue

As previously mentioned, temperatures today ended up cooler than expected; overnight lows, however, will remain unseasonably mild, in the mid to upper 30s inland and low 40s for the rest of the area, which is warmer than the average highs. Sunday will be similar to today, with mainly cloudy skies and fog; forecast high temperatures have been lowered, with highs in the mid to upper 40s inland and low 50s for the rest of the area, perhaps reaching the mid 50s near NYC in the warmer case scenario.

The warmest temperatures are expected to end up on Sunday night into Monday morning ahead of the approaching cold front. Temperatures will rise overnight into the 50s across the area, peaking on Monday morning in the low to mid 50s for most and the mid to upper 50s in the immediate NYC area. Temperatures will then drop on Monday afternoon and evening with mainly cloudy skies, although very little, if any rain is expected with the cold front.

Tuesday – Wednesday: Clouds Persist, Some Rain/Snow Possible

The cold front will slow down once moving offshore, with two waves of low pressure expected to develop on Tuesday and Wednesday. There is still some model uncertainty, although most of the precipitation associated with the low pressures should remain south of the area, and should be mostly rain with some snow in the northern end of the precipitation shield. Some rain or snow showers are likely for the area, especially west and southwest of NYC, on Tuesday, with partly to mostly cloudy skies and perhaps additional isolated rain/snow showers on Wednesday. Any snow accumulations will remain minimal.

Thursday – Beyond: Dry Pattern Returns; Mild Start, Then Cooling Down

Behind the wave of low pressure on Wednesday, a generally dry pattern is expected to develop again for the region, with most of the precipitation in the form of clippers in the Northeast. The initial cold surge on the 17-20th will focus well north of the area, with temperatures on Thursday still warmer than average, in the 40s. Through early next week, most days will remain near to slightly warmer than average, with highs in the 30s and 40s. For the longer range, however, a colder pattern will develop, along with the potential for a strong surge of cold air. The models have been going back and forth with the details, ranging from some GFS runs showing a near historic outbreak of cold air, which is less likely, to a more moderate form of a cold surge, although the pattern will trend colder after next weekend to early next week. Stay tuned for more information over the next few days.