Jan 28, 2014: Stormier Pattern Likely for February

Forecast Highlights:

gfs_namer_144_500_vort_htJanuary is on track to end on a dry note for most of the area, as a developing snowstorm south of the area brushes coastal locations with light snow on Wednesday, followed by a more sustained warming of temperatures into the 30s starting on Friday. Light rain and possibly snow are expected for Saturday-Saturday night, likely ending in time for the Super Bowl on Sunday evening, although signals for a more significant system exist towards the middle of next week (Image credit: NCEP MAG).


 


 

Monday, January 27 Observations:

Observations will be added soon.

 


 

Today – Friday: Cold Pattern Ends This Week

The significant cold that has affected the region in waves starting in early January, leading to the coldest month since January 2009 and the most number of single digit lows in a month in NYC since January 2005, is on track to end this week, but not before a final round of cold today. A strong arctic air mass entered the Midwest again over the last 1-2 days, with high temperatures well below zero, although the models overestimated the intensity of the cold air mass entering the Midwest, and as a result have backed off the magnitude of the cold over the region. Temperatures today are expected to reach the 15-20 degree range for most of the area with partly sunny skies and a breezy west wind, leading to wind chill values in the single digits.

6z GFS hour 24 at 6z Weds (1am), depicting the developing low pressure off the coast and light snow brushing Long Island. Snow can be seen extending into Georgia (Image credit: PSU e-Wall).

f24The cold front that pushed south of the area yesterday will stall near the southeast US, where a low pressure will develop later today into tomorrow, leading to a snowstorm affecting locations unusually south, including Georgia, South Carolina and North Carolina, with ice and freezing rain extending into coastal locations and even northern Florida. As the low pressure tracks northeast, most of the snow will stay offshore, although light snow showers are likely to brush Long Island, with up to a coating of snow possible in far eastern Long Island. Partly to mostly cloudy skies are otherwise expected with highs in the low to mid 20s. A gradual warm up will then continue into Thursday and Friday, with highs reaching the upper 20s-low 30s and the low-mid 30s, respectively.

 

Saturday – Beyond: Some Snow/Rain For Weekend, Potential For Midweek Storm

superbowl_1.28A stormier pattern is likely to develop heading into February with the collapse of western North American ridging, as a trough likely sets up near the western half of the US along with increased influence from ridging over the southeast US. The first such system is expected to affect the region on Saturday, with a low pressure tracking north of the area possibly producing some snow on Saturday morning before changing to rain by the afternoon or evening. There is some uncertainty with the exact track, although most of the precipitation at this time is likely to stay north of the area, with showers possible north of NYC on Saturday night into Sunday morning when the cold front moves through. With the current forecast timing for the cold front, high temperatures on Sunday would peak in the morning in the upper 30s-low 40s, falling into the upper 20s-low 30s by the evening with a breezy WNW wind for the Super Bowl.

A broad high pressure will build into the region for Monday, allowing for clearing skies and slightly cooler temperatures in the mid 30s. Attention then turns towards the western US, where the next shortwave trough is likely to emerge, and with ridging over the southeastern US preventing Sunday’s frontal boundary from progressing significantly to the south, a low pressure system appears likely to develop near the central US by Tuesday, with the system then tracking ENE along the frontal boundary and potentially affecting the area on Tuesday night into Wednesday. Even though this is still 8 days away, there is remarkable consistence with the model guidance in support of this storm potential, both the operational model and the ensemble guidance; the model ensembles are obtained by running the operational model multiple times with slightly different initialized conditions, with almost all of the GFS’ 20 individual ensemble members depicting measurable precipitation in this time frame. This time period, along with a shift to a ridge in the SE US, a trough in the western US, and continued ridging near Alaska, has some similarities to the early-mid December pattern, when the model guidance tended to have a better handle on medium-long range storm potentials than over the last two weeks, when persistent ridging over the western US meant most systems affecting the region originated from Canada. Despite this trend, however, the origins of this system can be traced back to the northern Pacific and northern Canada, both of which are regions with poor data sampling for the model guidance to ingest, and while probability of at least some precipitation is high in the mid-late week time frame, the exact set up is subject to change as the system approaches the medium range. More information will be posted on this storm potential over the next few days.

5 thoughts on “Jan 28, 2014: Stormier Pattern Likely for February

    • NYC Area Weather Post authorReply

      It does appear based on the latest trends that snow showers should reach NYC. Modeled QPF values are up to 0.10″; given dry air presence not all of that is likely to actually reach the ground, although the possibility for more than snow showers will be monitored.

Leave a Reply