After a period of colder and snowier than average conditions over the last 10 days, the trend for temperature extremes continues with unseasonable warmth making a brief return as temperatures surge into the 50s for highs on Friday and Saturday, and likely the 60s on Sunday. A trend for temperature swings is then likely with a strong mid week cool down followed by warmer temperatures for late next week.
Tonight – Monday: Unseasonably Warm, Some Rain Expected
The trough that was previously over the region has departed, with a broad southwesterly flow aloft covering the majority of the US in response to an upper level low digging southward over the western US, bringing the first period of warmer than average temperatures since the beginning of the month into the region. The warm up was evident today with highs rising into the 40s across the area. As a frontal boundary stalls northwest of the area, with a weak wave of low pressure riding along the boundary on Friday night, the warming trend will continue on Friday and Saturday, with highs on Friday rising into the low-mid 40s inland and mid-upper 40s elsewhere. More widespread cloud cover will spread in overnight into Saturday with highs in the low to mid 50s across the area.
As the aforementioned upper level low is picked up by a stronger trough entering the Midwest region, a stronger surface low pressure will develop near the south central US and track into the northern Northeast region, dragging a warmer air mass into the area for Sunday with highs expected to rise into the low to mid 60s, with upper 60s possible near or southwest of NYC. While the storm will produce significant precipitation, almost all of the rain is currently likely to stay north of the area, with scattered showers possible on Sunday. The stronger low will then push the frontal boundary through the area overnight, with some showers likely but with uncertainty regarding the rain totals; at this time, at least up to 1/2 inch of rain is likely. Temperatures are expected to remain in the 50s-low 60s overnight, and are still expected to peak in the low 50s for highs on Monday before falling into the afternoon and evening.
Tuesday – Beyond: Cold Midweek, Warmer Late Week
Since late November, the theme of the current pattern has consisted of temperature swings from one extreme to another, with cold and breezy conditions expected to make a return on Tuesday as a trough moves through the region as high temperatures likely peak in the low-mid 30s across the area. Colder overnight temperatures are expected as well, falling into the 20s across the area with upper 10s for interior locations. As another trough enters the Midwest region, however, rising heights aloft are expected over the region with the trough moving out, leading to another moderation in temperatures for the late week, likely returning into the 40s for highs by Friday. Some of the latest model guidance indicates the possibility of a storm affecting the area on Friday; this is only a potential at this time, however, and any storm potential does not appear to be significant at this time, with rain preferred over snow as the main precipitation type. Drier conditions are likely by next weekend with another transient cool down.
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Wednesday, December 18 Observations:
Behind Tuesday’s snowstorm, a transient cool air mass moved through the region, keeping cool temperatures in place while drier conditions and more sunshine made a return, with high temperatures peaking in the mid 30s across most of the area.
The highest temperature was 38 degrees in JFK airport, and the coolest high temperature was 32 degrees in Yorktown Heights, NY.
Tuesday, December 17 Observations:
Read more: December 17 Storm Updates
The second significant snow event of the winter affected the area on December 17. With another cold air mass over the region and initially fair skies, most of the area fell into the upper 10s-20s for morning lows, but towards interior NW NJ, SE NY and interior CT, temperatures plummeted into the lower single digits, as low as 1 degree in Sussex, NJ and 0 degrees in Montgomery, NY. Light to moderate snow developed after 4-5am, ending by 8-9am for most locations with up to an inch. After a temporary break, snow redeveloped around 12pm, falling moderately at times north of NYC while changing to rain in Long Island and mixing with rain/sleet near and west/SW of NYC. Precipitation mostly ended by 5pm with dry conditions overnight.
Due to the frigid morning lows and cloud cover/snow, interior locations only saw highs in the upper 10s to low 20s. Closer to NYC and southern CT, temperatures reached the mid 20s-low 30s. Long Island, which was closest to the low pressure, saw a brief spike in temperatures into the mid 30s-mid 40s. The highest temperature was 46 degrees in Westhampton Beach, NY, and the coolest high temperature was 18 degrees in Port Jervis, NY and Andover, NJ.