Jan 6, 2013: Mild Week Coming Up

Forecast Highlights:

The dry pattern that has been in place since the 12/29 storm continued through the last week, with only scattered snow showers observed last night with as much as 1/2 inch towards parts of southern NJ, PA, and southern New England. While temperatures will moderate through next week, ending up much warmer than average with highs in the 40s and occasionally 50s, no precipitation is expected until late this coming week, when a more active pattern develops in the US with the first rain event affecting the region.

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Note: As it will be a while until the next snow potential affects the area despite the time of the year, a poll has been opened in the right side of the blog for the next time frame when snow is possible. The poll will remain open until Thursday, and results will be posted on Friday.


Tonight - Thursday: Mild, Dry

This morning, a light precipitation event affected the northern Mid Atlantic, the first time since the December 29th storm 8 days ago. While scattered snow showers were observed, this failed to produce measurable precipitation for most of the area. A steadier period of light snow, however, was observed towards the southern half of NJ and the central Mid Atlantic, where minor accumulations up to 1/2 inch were reported. With this out of the way, the next precipitation event to affect the region will only be on Friday, 5 days from now, ending a 13-day stretch of no measurable precipitation.

Mostly cloudy skies will continue tonight with a shortwave moving through the Mid Atlantic, with lows falling into the mid to upper 20s inland and the upper 20s to mid 30s for the rest of the area. Clearing skies are expected for Monday with highs in the mid to upper 30s inland and upper 30s to low 40s for the rest of the area. A high pressure will slide south of the area overnight, with southwest winds expected for Tuesday and Wednesday. Both days will be mostly sunny with highs in the low to mid 40s inland and the mid to upper 40s for the rest of the area; Wednesday will be the warmer of the two, with highs approaching 50 degrees in the immediate NYC area.

A weak low pressure will quickly move across southeastern Canada on Wednesday night, becoming a strong low pressure southeast of Newfoundland, with snow showers towards Maine and a trough quickly moving through the region. Despite the trough moving through, temperatures will fail to cool down by much, reaching the low 40s inland and mid 40s for the rest of the area on Thursday with partly sunny skies.


Friday - Next Weekend: Even Warmer; Rain Returns

The first widespread storm to affect the region since late December will produce light to moderate rain across the region on Friday, ending a 13 day stretch of no measurable precipitation. There have been noticeable changes with the model guidance from a few days ago; while the GFS originally supported a strong storm west of the region on Wednesday, the GFS is no longer showing the shortwave over Texas phasing, and instead the models bring it through the region on Friday with a weak low pressure producing widespread light to moderate rain across the region. There continue to be differences, with the GFS taking the shortwave well west of the region into Canada while the ECM and CMC instead take it east through the region and then southeast into the Atlantic.

The differences above, however, don't have much of an impact on the scenario expected for the NYC area; the current expectation is for clouds to increase late on Thursday with occasional showers expected on Friday. Highs are likely to be in the lower to mid 40s across the area, with temperatures failing to drop much overnight. Behind this low pressure, even warmer temperatures are expected for the weekend with a strong ridge over the eastern US and a developing low pressure in the central US, moving towards the Great Lakes or Midwest region by the late weekend or early next week; high temperatures are expected to reach the 50s across most of the area for the weekend, perhaps approaching 60 degrees for warmer parts of the area, with 60s further south into the central and southern Mid Atlantic. These temperatures will be significantly warmer than average; average high temperatures this time of the year are in the 30s.


Next Week: Additional Rain Expected

With a low pressure moving towards the north central US, a cold front is expected to move towards the region early next week with rain expected. Behind the cold front, temperatures will somewhat cool down but with the overall pattern, consisting of the MJO in phases 4-5-6 and a -EPO but with a negative PNA, a strong cold air mass will fail to settle over the region with the colder temperatures generally staying in the central and western US. Uncertainty increases by this point regarding the more specific details, with some GFS runs developing another wave of low pressure over the region which other models do not have. Through January 15th or beyond, the pattern is expected to generally remain warmer than average with more rain than snow potentials for the region.