donsutherland1

Morning thoughts... Today will be partly sunny and unseasonably cold. Temperatures will likely top out in the upper 20s and lower 30s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 29° Newark: 30° Philadelphia: 32° A system will likely bring a swath of 1”-3” snow to parts of the region with local amounts of up to 4”, especially north and west of Newark and New York City. Central Park could even pick up an inch or two of snow, but there is uncertainty about the southern extent of the snow.

Final at JFK: 6.9”. It was a nice storm.

Today's storm brought a large swath of 4"-8" snows with some locally higher amounts to the New York City region. Even heavier amounts were reported in parts of New England. Select accumulations included: Bridgeport: 7.4" East Killingly, CT: 9.6" Islip: 5.1" New York City: 4.5" Newark: 5.6" Norfolk, MA: 12.0" Sharon, MA: 12.0" Syosset (1 N), NY: 8.4" Westwood (1 NNE), NJ: 9.1" Another light snow event could affect parts of the region on Tuesday. Up in Canada's Nunavut Province, temperatures will reach record high levels tomorrow through at least Monday. That push of exceptional warmth will dislodge a frigid Arctic air mass currently located over northwestern Canada. That cold air mass will likely enter the Northern Plains States early next week. Afterward, it could slowly advance eastward and possibly reach the Middle Atlantic and southern New England regions just before mid-month. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.7°C for the week centered around January 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.71°C and the ENSO Region 3.4 anomaly has averaged -1.03°C. La Niña conditions will likely prevail at least through meteorological winter. The SOI was +13.26 today. Today, the preliminary Arctic Oscillation (AO) figure was -3.730 today. On February 6 the MJO was in Phase 7 at an amplitude of 2.145 (RMM). The February 5-adjusted amplitude was 2.115. Based on the latest guidance, no significant stratospheric warming event is likely through the second week of February. The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 22.0" snow. Based on sensitivity analysis applied to the latest guidance, there is an implied 80% probability that New York City will have a colder than normal February. February will likely finish with a mean temperature near 32.5°.

Five photos from today’s snowstorm:

Around 8” in Rye. Light snow continues to fall.

A quick video clip:

4” in Mamaroneck, NY.

Snow has just moved into Larchmont, NY in southern Westchester County. After a short period of flurries, it is now snowing moderately.

Morning thoughts... On this date in 1967, a major snowstorm was burying the region. This time around, a fast-moving system will provide parts of the region with a period of heavy snow, but smaller accumulations are likely. New York City, Newark, and Philadelphia will likely pick up 3”-6” snow while Islip sees 4”-8”. Locations such as Newburgh and Poughkeepsie should pick up 2”-4” snow. The HREF ensemble system shows a large area of 4”-6” snows with 6”-8” (and even an area of 8”-10” on eastern Long Island) across northeast New Jersey and eastward. This data provides some confidence that total snowfall will likely exceed the lowest amounts shown on some of the global models. At 8:40 am, the first snow was falling in parts of New York City, including Brooklyn and flurries extended into southern Westchester County. Snow will fall moderately to occasionally heavily at times, especially from late morning into the afternoon. Where banding develops, snow could fall at a rate of 1” per hour. Temperatures will likely top out in the lower and middle 30s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 35° Newark: 35° Philadelphia: 36° Tomorrow will be fair and cold, but another system could bring a period of light snow on Tuesday. Areas to the north and west of Newark and New York City have the best chance of seeing accumulating snow from that system.

A developing fast-moving storm will bring a swath of snow across parts of the region tomorrow with the highest amounts occurring along the coastline from central New Jersey to southern New England, including Long Island. There is some uncertainty as to how far north the heaviest bands will make it. The 12z HREF and 18z NAM and HRRR favor their being located farther north consistent with the modeled lift. At present, on account of some of the major global guidance and the 3 km NAM favoring a further south positioning of the bands, a compromise idea is adopted. Snowfall estimates for select cities: Boston: 4"-8" Bridgeport: 3"-6" Islip: 4"-8" New York City: 3"-6" Newark: 3"-6" Philadelphia: 3"-6" Poughkeepsie: 2"-4" Providence: 4"-8" Another light snow event could affect parts of the region on Tuesday. Up in Canada's Nunavut Province, temperatures will reach record high levels tomorrow through at least Monday. That push of exceptional warmth will dislodge a frigid Arctic air mass currently located over northwestern Canada. That cold air mass will likely enter the Northern Plains States early next week. Afterward, it could slowly advance eastward and possibly reach the Middle Atlantic and southern New England regions just before mid-month. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.7°C for the week centered around January 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.71°C and the ENSO Region 3.4 anomaly has averaged -1.03°C. La Niña conditions will likely prevail at least through meteorological winter. The SOI was +0.62 today. Today, the preliminary Arctic Oscillation (AO) figure was -3.224 today. On February 5 the MJO was in Phase 7 at an amplitude of 2.111 (RMM). The February 4-adjusted amplitude was 2.001. Based on the latest guidance, no significant stratospheric warming event is likely through the second week of February. The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 17.5" snow.

From the discussion, details about the dynamics the NWS was relying on more than just the modeled QPF: THE GFS SHOWS EXCELLENT LIFT IN THE DENDRITIC GROWTH ZONE (-12C TO -18C) EVEN AS FAR NORTH AS THE LOWER HUDSON VALLEY WHERE CURRENT FORECAST LIQUID AMOUNTS ARE LOWER. FRONTOGENESIS ON THE NW SIDE OR COLDER SIDE OF THE MIDDLE LEVEL LOW IS IMPRESSIVE FOR ABOUT A 3-6 HOUR PERIOD FROM LATE MORNING INTO THE AFTERNOON ACROSS MUCH OF THE REGION.

RGEM=RDPS Icon is not available.

Dynamics suggest more QPF than modeled. That’s part of the reason OKX is more aggressive than what is modeled. We’ll know tomorrow how things worked out.

He’s alive, but retired.

You’re welcome. Hopefully, the snow shield will be more expansive on the other guidance and on later runs.

GDPS.

Here’s the top 10 on XMACIS: Maximum 8-Day Total Snowfall for New York-Central Park Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Missing Days Last value also occurred in one or more previous years. Period of record: 1869-01-01 to 2021-02-05 1 29.2 1947-12-30 0 - 29.2 1947-12-29 0 - 29.2 1947-12-28 0 4 28.9 1947-12-27 0 5 28.6 1947-12-26 0 6 27.9 2016-01-24 0 - 27.9 2016-01-23 0 8 27.5 2016-01-29 0 - 27.5 2016-01-28 0 - 27.5 2016-01-27 0

It has been a very snowy period. It will be interesting to see how things stack up over a 2- or 3-week period, as there may be some additional snowfall opportunities.

Morning thoughts... Through February 5, New York City has seen 15.4” snowfall for the month. With a moderate to significant snowfall likely tomorrow, Central Park could see 20” monthly snowfall for the first time in February since 2014 when 29.0” snow accumulated. Today will be mostly sunny and seasonably cold. Temperatures will likely top out in the lower 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 40° Newark: 40° Philadelphia: 44° Snow will overspread the region before sunrise tomorrow. Snow will then fall moderately to occasionally heavily at times into the afternoon. A general 4”-8” snowfall with locally higher amounts is likely.

As bad as the 21z SREFs were, there could be worse. EPS member e17 forecast no snow whatsoever for New York City through February 20. In reality, the guidance has remained relatively consistent with the usual inter-cycle shifting since 12z. As such, much of the region from central New Jersey north and eastward across Newark and New York City and Long Island, and along the southern New England coastline remains in line for a solid 4”-8” snowfall with locally higher amounts. For those who are interested, EPS member e03 was the snowiest member, showing 37” snow through February 20.

JFK is 20.0”.

Nassau County is in a good spot for this storm.

In the wake of today's light precipitation event, the weekend will start fair and seasonably cold. However, a fast moving storm will bring a swath of snow across parts of the region on Sunday with the highest amounts occurring along the coastline from central New Jersey to southern New England, including Long Island. Initial snowfall estimates for select cities: Boston: 4"-8" Bridgeport: 4"-8 Islip: 4"-8" New York City: 4"-8" Newark: 4"-8" Philadelphia: 3"-6" Poughkeepsie: 2"-4" Providence: 5"-10" Up in Canada's Nunavut Province, temperatures will reach record high levels tomorrow through at least Monday. That push of exceptional warmth will dislodge a frigid Arctic air mass currently located over northwestern Canada. That cold air mass will likely enter the Northern Plains States early next week. Afterward, it could slowly advance eastward and possibly reach the Middle Atlantic and southern New England regions just before mid-month. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.7°C for the week centered around January 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.71°C and the ENSO Region 3.4 anomaly has averaged -1.03°C. La Niña conditions will likely prevail at least through meteorological winter. The SOI was +8.26 today. Today, the preliminary Arctic Oscillation (AO) figure was -2.773 today. On February 4 the MJO was in Phase 7 at an amplitude of 1.998 (RMM). The February 3-adjusted amplitude was 1.987. Based on the latest guidance, no significant stratospheric warming event is likely through the second week of February. The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 17.5" snow.

Is that an old forecast? The guidance has grown more robust at 12z.

It sometimes overshoots. One should also use the maximum temperature algorithm for a better perspective. Here’s a paper on the Cobb Method: https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1013&context=geoscidiss