Mar 7, 2014: Above Normal Temps Briefly Return

Forecast Highlights:

temp26A coastal low off the Mid Atlantic coast is producing widespread rain south of New Jersey, with its associated cloud cover extending north into the NYC area. The coastal low will depart tonight with a cold front approaching on Saturday, allowing for a brief spike in temperatures into the mid 40s-low 50s. A slight cool down is anticipated for Sunday followed by continued near average temperatures for Monday and Tuesday, but with temperatures expected to fall again late next week as a storm system likely affects the region (Image credit: PSU e-Wall).

 

 


 

Today – Sunday: Clouds Depart, Temperatures Warm Up

rad_3.7nam_3.7

Posted above from left to right are the latest available surface analysis and radar composite from WPC, and the initialized GFS 500 millibar heights and vorticity from NCEP MAG; both are valid at 18z (1pm). The main feature to note in the eastern US is a strong low pressure off the coast of North Carolina, with a minimum pressure of 998 millibars. As the 500mb map shows, however, there is virtually no interaction with the northern stream, which is well to the north over Canada, with a lack of a fresh cold air source resulting in precipitation type primarily falling as rain except for higher elevations, where some mixed precipitation has occurred. This system will continue to slowly track NE and offshore, with mainly cloudy skies to continue today over the NYC area before clearing tonight.

Following the departure of the coastal low, a cold front near Minnesota will continue to slide east towards the region, with a west-WNW flow expected during the day on Saturday as the front moves through the area. With some sunshine expected, along with a relatively mild air mass ahead of the frontal passage, temperatures are expected to rise into the 45-50 degree range across most of the area, which is near to even slightly above average. A transient cool air mass will quickly transverse the region on Sunday behind this front, with mostly cloudy skies and highs in the upper 30s, along with a breezy NW wind at 10-15 mph.

 

Sunday – Next Week: Warm Start, Cold/Possibly Stormy Ending To Week

A slightly longer lasting warm up is expected behind Sunday’s cool down as a strong jet streak enters SW Canada over the short range, allowing for ridging to rapidly expand eastward through Sunday into Monday and cutting off the current shortwave trough over the SW US from the main flow, leaving it as an upper level low slowly drifting east through northern Mexico or southern Texas. These warmer temperatures will be most noticeable on Monday and Tuesday, with partly to mostly cloudy skies expected on both days as highs on Monday rise into the mid-upper 40s and the upper 40s-mid 50s on Tuesday.

Attention then turns to Wednesday and Thursday, with the latest model guidance depicting yet another snowstorm in continuation of the stubborn winter pattern that refuses to break down despite the time of the year. As the mid-upper level ridging shifts east into the northeast US, a strong shortwave trough is expected to enter the NW US on Monday, approaching the south central US while the earlier upper level low over northern Mexico is forced to progress eastward and later offshore. From there the model guidance significantly diverges, with the ECMWF depicting a sharper shortwave trough axis over the central US with the northern stream from Canada digging further south, aiding in the development of a strong low pressure tracking south of the area with a wintry mix in NYC and heavy snow to the north, while the GFS is weaker and flatter with the system with light to moderate plain snow affecting the area. There is, however, agreement regarding yet another round of cold temperatures entering the region with this system, with modeled low temperatures back into the 10s.

As the previous storm on March 2-3 has shown, model consistency does not necessarily imply accuracy, regardless of how many runs show a major snowstorm, and this time frame does need to be monitored with caution. With the polar vortex likely to be further north than with that event leading to less suppression to some extent, however, there is higher confidence of widespread precipitation affecting the area, but with uncertainty regarding the specific details, including the exact precipitation types and amounts, although snow is likely to be involved given the cold air mass accompanying the system with the southward extent depending on the strength and track of the low pressure. Probability of precipitation will be increased to 60% with the 8-day outlook to be updated later this afternoon, as the possibility of a suppressed scenario cannot be completely ruled out, albeit with a somewhat lower likelihood than with the early month storm. Given the current uncertainty, it is too early to discuss snow accumulations at this time, with these details to be gradually narrowed down over the next few days as details become clearer.

2 thoughts on “Mar 7, 2014: Above Normal Temps Briefly Return

  1. Anonymous Reply

    Sir, what happened to your wonderful daily OBS for the NYC Area over the past month?

    • NYC Area Weather Post authorReply

      I haven’t been able to update them recently, although I am making gradual progress on getting the summaries up to date. I am also trying to find an efficient method of moving them to a single page where they can be archived easily; so far I have this page up for archived daily temperature maps, and I plan to add a new format for the daily summaries soon as well.

Leave a Reply