donsutherland1

Colder air now covers the region. Another shot of cold air will arrive to end the week. However, the cold will be far from severe. No Arctic air appears likely through the remainder of December. A transition to a colder pattern could commence during the first week of January. Severe cold appears unlikely early in the transition. The ENSO Region 1+2 anomaly was +1.5°C and the Region 3.4 anomaly was +2.0°C for the week centered around December 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.85°C and the ENSO Region 3.4 anomaly has averaged +1.95°C. A basinwide El Niño event is ongoing. El Niño conditions may strengthen somewhat further this month. The SOI was +0.47 today. The preliminary Arctic Oscillation (AO) was +2.292 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. On December 17 the MJO was in Phase 7 at an amplitude of 1.661 (RMM). The December 16-adjusted amplitude was 1.737 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 97% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.8° (3.7° above normal).

The powerful storm responsible for bringing record daily rainfall amounts to the Southeast and parts of the Middle Atlantic region, including a possible 24-hour state rainfall record in South Carolina, brought heavy rain to the region overnight into this morning. Gumboro, DE (5.74"); Butler, NJ (5.53"); and, Stockley, DE (5.52") were among locations receiving rainfall of 5" or more today. A number of 19th century daily rainfall records, including Concord's and Central Park's records from 1876, were broken. Regional rainfall amounts included: Albany: 2.13" (old record: 1.52", 1887) Atlantic City: 2.27" (old record: 1.10", 1986) Bangor: 2.19" (old record: 0.68", 1975) Binghamton: 2.06" (old record: 0.90", 1990) Boston: 1.64" (old record: 1.44", 1951) Bridgeport: 1.87" (old record: 1.14", 1951) Burlington: 2.02" (old record: 0.85", 1954) Concord: 2.28" (old record: 1.60", 1876) Hartford: 2.17" (old record: 1.95", 1986) Islip: 1.65" (old record: 1.41", 2012) Manchester: 2.46" (old record: 1.29", 1954) New Haven: 1.77" (old record: 1.24", 1961) New York City-Central Park: 2.21" (old record: 1.30", 1876) New York City-JFK Airport: 1.47" (old record: 1.32", 1986) New York City-LaGuardia Airport: 2.13" (old record: 1.29", 1961) Newark: 2.75" (old record: 1.22", 1951) Philadelphia: 2.19" (old record: 1.72", 1977) Poughkeepsie: 2.23" (old record: 1.52", 1887) Providence: 2.42" (old record: 1.46", 1954) Scranton: 2.16" (old record: 0.93", 1961) Trenton: 2.17" (old record: 1.80", 1887) White Plains: 2.64" (old record: 1.51", 2000) Worcester: 2.82" (old record: 1.79", 1954) In the warm sector of the storm, parts of the region also experienced daily record high temperatures. Daily records included: Bangor: 61° (old record: 53°, 1954 and 2000) Boston: 63° (old record: 61°, 1915 and tied in 1928 and 1990) Caribou: 57° (old record: 54°, 2000) Concord: 62° (old record: 59°, 1928) Hartford: 64° (old record: 58°, 1954) Islip: 61° (old record: 59°, 1984) Manchester: 64° (old record: 54°, 1954) New Haven: 62° (old record: 54°, 1966 and 2006) New York City-LaGuardia Airport: 63° (old record: 62°, 2006) Newark: 64° (tied record set in 1937) Portland: 59° (old record: 53°, 1996) Poughkeepsie: 64° (old record: 55°, 1954) Westfield, MA: 63° (old record: 54°, 1928) Westhampton: 62° (old record: 56°. 2012 and 2015) White Plains: 63° (old record: 61°, 2006) Worcester: 61° (old record: 57°, 1928) Behind the storm, it will turn colder, but not severely cold. Tomorrow could see variably cloudy conditions with some passing snow flurries or snow showers, generally well north and west of New York City and Newark. No Arctic air appears likely through the remainder of December. A transition to a colder pattern could commence during the first week of January. Severe cold appears unlikely early in the transition. The ENSO Region 1+2 anomaly was +1.5°C and the Region 3.4 anomaly was +2.0°C for the week centered around December 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.85°C and the ENSO Region 3.4 anomaly has averaged +1.95°C. A basinwide El Niño event is ongoing. El Niño conditions may strengthen somewhat further this month. The SOI was +7.42 today. The preliminary Arctic Oscillation (AO) was +2.835 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. On December 16 the MJO was in Phase 7 at an amplitude of 1.737 (RMM). The December-adjusted amplitude was 1.617 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.5° (3.4° above normal).

Earlier this morning, drier air punched into the storm's circulation bringing breaks in the clouds and a short period of sunshine.The wind had largely died down.

McLellanville 1W, SC picked up 16.32" of rain yesterday. If validated, it would break the 24-hour record of 14.80" from Myrtle Beach during Hurricane Floyd on September 16, 1999 for the all-time 24-hour record.

Daily record highs have already fallen at Islip, New Haven, New York City-LaGuardia Airport, Poughkeepsie, and White Plains. The record high was tied in Newark.

Warmth was more widespread and somewhat more intense than what had been shown on the weekly guidance.

24-hour HREF map:

As of 10 pm, rain was falling heavily in Atlantic City, Baltimore, Philadelphia, Sterling, and Washington, DC. The heavy rain will continue to advance northward. The New York City area will likely see its heaviest rain during a period that runs from midnight to about 8 am. The area of heaviest rain still appears likely to occur north and west of Newark and New York City. Strong winds will lash the coastline and coastal flooding is likely at times of high tide. The latest HREF guidance is below:

Daily rainfall at McClellanville (7 NE), SC is now 13.30".

Parts of the Southeast saw record daily rainfall. Daily records through 5 pm included: Charleston: 2.57" (old record: 0.66", 1975) Charleston (Downtown): 4.36" (old record: 1.18", 1923) ***New December monthly record*** Columbia, SC: 2.20" (old record: 1.16", 1888) Fayetteville: 2.30" (old record: 1.68", 1970) Greensboro: 1.64" (old record: 1.52", 1930) Lumberton, NC: 2.58" (old record: 1.90", 1970) Myrtle Beach: 3.69" (old record: 0.50", 1994) Raleigh: 2.05" (old record: 1.35", 1890) Savannah: 3.16" (old record: 1.96", 1880) Wilmington, NC: 2.83" (old record: 0.88", 1887) McClellanville (7 NE), SC was deluged by 12.21" of rain. That broke the all-time daily precipitation record of 10.37" that was set on September 5, 2019. The highest December daily amount for South Carolina in the xmACIS database is 8.10" that fell at Pawleys Island (2.6N) on December 24, 2019. Heavy rain from that storm has reached Norfolk. It will continue to advance northward this evening. Overall, the powerful storm will bring a general 2"-4" rainfall to a wide swath of the region by the time the rain ends tomorrow. Locally higher amounts could reach or exceed 5". Strong winds gusting up to 50 mph could create tree and power line damage. Coastal flooding, especially tomorrow, is likely. Behind the storm, it will turn colder, but not severely cold. Tuesday could see variably cloudy conditions with some passing snow flurries or snow showers, generally well north and west of New York City and Newark. No Arctic air appears likely through the remainder of December. A transition to a colder pattern could commence during the first week of January. The ENSO Region 1+2 anomaly was +1.3°C and the Region 3.4 anomaly was +1.9°C for the week centered around December 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.97°C and the ENSO Region 3.4 anomaly has averaged +1.92°C. A basinwide El Niño event is ongoing. El Niño conditions will may strengthen somewhat further this month. The SOI was +7.42 today. The preliminary Arctic Oscillation (AO) was +2.835 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. Based on sensitivity analysis applied to the latest guidance, there is an implied 93% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.4° (3.3° above normal).

The 12/17 12z HREF:

Prompt updated:

Week ahead numbers:

Under mainly sunny skies, the temperature again rose into the 50s across the region. The mild weather will continue through the weekend. Meanwhile Florida was picking up moderate to heavy rain. Fort Lauderdale had picked up 1.12" as of 5 pm, which surpassed the daily record of 1.00" from 1958. West Palm Beach had 1.47", which was approaching the daily record of 1.70" that had been set in 1892. Parts of the Southeast could see December record 2-3 day rainfall totals. That storm will bring a general 2"-4" rainfall to a wide swath of the region tomorrow into Monday. Locally higher amounts could reach or exceed 5". Strong winds gusting up to 50 mphs could create tree and power line damage. Coastal flooding, especially on Monday, is likely. No Arctic air appears likely through the remainder of December. A transition to a colder pattern could commence during the first week of January. The ENSO Region 1+2 anomaly was +1.3°C and the Region 3.4 anomaly was +1.9°C for the week centered around December 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.97°C and the ENSO Region 3.4 anomaly has averaged +1.92°C. A basinwide El Niño event is ongoing. El Niño conditions will may strengthen somewhat further this month. The SOI was +11.99 today. The preliminary Arctic Oscillation (AO) was +1.874 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. Based on sensitivity analysis applied to the latest guidance, there is an implied 90% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.1° (3.0° above normal).

I agree regarding genuine Arctic air.

I agree with you about the thaw and February.

Winters 1972-73 (15.17") and 1973-74 (15.27") were actually much wetter than normal (December-February precipitation). Storm tracks played a major role in that snow drought.

I expect that the breakdown in Atlantic blocking is temporary. It should redevelop in January. The broader pattern should also be transitioning during the first week of January.

The milk carton was a template. The photo was taken in Patchogue during the January 2022 storm.

If the CFSv2 is right, patience remains in order. Genuine winter weather for the NYC and Philadelphia areas appears unlikely through most of the month. Periodically, the GFS and even ECMWF have flirted with the idea of some snowfall next week, but have since backed off. CFSv2: Status of Winter:

Unfortunately, it does.

I'm looking forward to breaking this drought.

New York City has unlocked another sad winter record, as its unprecedented streak without 1" or more snowfall reaches 671 days today. New York City will record its 686th consecutive day without 2" or more daily snowfall. Both streaks look likely to continue through at least the next week, if not longer.

While New York City has reached 670 consecutive days without having seen daily snowfall of an inch or more, I asked AI to generate some images of snowstorms. The images were then processed to create a 19th century feel. There were some issues creating the images on the AI side, but all in all, they worked out reasonably well.

Under brilliant sunshine, the temperature soared into the middle and upper 50s across the region. The mild weather will continue through the weekend. A significant rainstorm is likely Sunday evening into Monday. A general 1"-3" of rain is possible with locally higher amounts. Strong winds and coastal flooding are likely. Tree and power line damage could occur. No Arctic air appears likely through the remainder of December. A transition to a colder pattern could commence during the first week of January. The ENSO Region 1+2 anomaly was +1.3°C and the Region 3.4 anomaly was +1.9°C for the week centered around December 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.97°C and the ENSO Region 3.4 anomaly has averaged +1.92°C. A basinwide El Niño event is ongoing. El Niño conditions will may strengthen somewhat further this month. The SOI was -7.68 today. The preliminary Arctic Oscillation (AO) was +1.152 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. Based on sensitivity analysis applied to the latest guidance, there is an implied 84% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 41.8° (2.7° above normal).