donsutherland1

It should be noted that since winter 1869-70, there is only 1 case where seasonal snowfall through February was less than 10" and March had an 8" or greater snowfall in New York City: 1956. Seasonal snowfall through February 1956 was 8.2". The February 1956 AO average was -2.029. The second lowest figure was 10.8" in 1981 (February AO: -0.331).

The temperature fell to 16 degrees on December 19.

The President's Day snowstorm was the highlight of a remarkably cold winter. Almost the entire CONUS was colder to much colder than normal.

At 7 pm EST, the temperature was 10° in Chicago, 19° in Detroit, 33° in Pittsburgh, 43° in New York City,and 47° in Philadelphia. The cold that has now moved into the Great Lakes region will be pushing into the region overnight. As a result, readings will be much below normal tomorrow and on Saturday. The lowest temperatures on Saturday morning could fall into the teens in New York City and Philadelphia. Readings in the lower teens and perhaps single digits are likely outside both cities. But then winter's latest effort to take hold will fail again. Warmer air will quickly return. It is likely that the second half of February will be warmer than normal overall. During that time, cold shots will likely be of a short duration. Consistent with the pattern and supported by most of the guidance, no significant snowfalls (6" or more) are likely in the major Middle Atlantic cities through at least the first three weeks of February. There is a greater but still fairly low probability for Boston to see such a snowstorm. On this date in 2014, Philadelphia received a daily record 10.4" snowfall. This winter, the city is mired in a deepening snow drought. Winter 2019-2020 is just the 7th winter on record that saw Philadelphia receive less than 2" seasonal snowfall through February 13. Mean total snowfall for the 6 prior cases was 3.8" vs. the historic mean figure of 22.6". In addition, 100% of such winters wound up with less than 10" seasonal snowfall vs. 16% of winters in the historic record. The snowiest case from those prior winters was 1931-32 with 8.0" seasonal snowfall. The ENSO Region 1+2 anomaly was +0.8°C and the Region 3.4 anomaly was +0.2°C for the week centered around February 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.22°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -12.49 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.860. No significant stratospheric warming is likely through February 21, but the upper stratosphere above 3 mb will likely be warm. Wave 2 activity will remain relatively suppressed. Overall, most of the stratosphere is forecast to remain cold on the EPS into the third week of February. On February 12, the MJO was in Phase 6 at an amplitude of 1.121 (RMM). The February 11-adjusted amplitude was 1.211. 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 February and an implied 50% probability that February 2020 will be among the 10 warmest such months on record. Finally, a sizable majority (>80%) of years during which the AO has been, on average, strongly positive during the first 15 days of February were followed by a warmer than normal March. The preliminary February 1-12 AO average is +2.926. Recent rapid warming in ENSO Region 1+2 has also typically preceded a warmer than normal March and spring in the Middle Atlantic region.

Philadelphia had measurable snowfall in January 1979 (first was 1/5 when 1.2" fell). The February days with measurable snowfall were as follows: 2/7 7.6" 2/12 4.8" 2/14 0.4" 2/15 0.3" 2/16 0.2" 2/18 0.4" 2/19 13.9"

The NOAA also reported that January 2020 was the warmest January on record globally. https://www.ncdc.noaa.gov/sotc/global/202001

On February 9, 2020, a record temperature of 20.75 degrees C (69.35 degrees F) was recorded on Antarctica's Seymour Island. https://www.theguardian.com/world/2020/feb/13/antarctic-temperature-rises-above-20c-first-time-record

Winter 2019-2020 became the 7th winter on record that saw Philadelphia receive less than 2" seasonal snowfall through February 12. Mean total snowfall for the 6 prior cases was 3.8" vs. the historic mean figure of 22.6". In addition, 100% of such winters wound up with less than 10" seasonal snowfall vs. 16% of winters in the historic record. The snowiest case from those prior winters was 1931-32 with 8.0" seasonal snowfall. Winter 2019-2020 is also only the 3rd winter on record to receive less than 1" seasonal snowfall through February 12. The others were 1972-73 (0.0") and 1997-98 (0.7").

Tomorrow will very likely see temperatures top out in the 50s in much of the Middle Atlantic region. However, a brief shot of modified Arctic air will move into the region for Friday and Saturday. The lowest temperatures could fall into the teens in New York City and lower teens and perhaps single digits outside the City. Afterward, warmer air will quickly return. It is likely that the February 15-21 period will be warmer than normal overall. Any cold shots would likely be of a short duration. The general above normal temperature regime could persist afterward. Consistent with the pattern and supported by most of the guidance, no significant snowfalls (6" or more) are likely in the major Middle Atlantic cities through at least the first three weeks of February. There is a greater but still fairly low probability for Boston to see such a snowstorm. The ENSO Region 1+2 anomaly was +0.8°C and the Region 3.4 anomaly was +0.2°C for the week centered around February 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.22°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -9.03 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.286. No significant stratospheric warming is likely through February 20, but the upper stratosphere above 5 mb will likely warm toward mid-February. Wave 2 activity will remain relatively suppressed. Overall, most of the stratosphere is forecast to remain cold on the EPS into the third week of February. On February 11, the MJO was in Phase 5 at an amplitude of 1.204 (RMM). The February 10-adjusted amplitude was 1.540. Based on sensitivity analysis applied to the latest guidance, there is an implied 86% probability that New York City will have a warmer than normal February and an implied 56% probability that February 2020 will be among the 10 warmest such months on record. Finally, a sizable majority (>80%) of years during which the AO has been, on average, strongly positive during the first 15 days of February were followed by a warmer than normal March. The preliminary February 1-12 AO average is +2.926. Recent rapid warming in ENSO Region 1+2 has also typically preceded a warmer than normal March and spring in the Middle Atlantic region.

I hope we don't get buried in pollen.

Good news: Climate scientist Brian Brettschneider's Twitter account has been restored to full functionality.

The ridging across Europe teleconnects to troughs in the Middle East and Northern Africa during the winter.

I don’t know. The factors responsible for the seasonal AO state remain uncertain. The recent extreme North Atlantic storms have played a recent role.

3.8” at JFK. MPO hasn’t measured snow since 1988-89. Up to then, its lowest seasonal snowfall was 22.1” during winter 1954-55.

Recent paper on the 2018-19 SSW event: https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3643

Another warmer than normal day and more signs of spring. The coming cold shot will be short-lived and warmer than normal conditions should quickly return. Photo courtesy of my brother in Mamaroneck, NY from a short time ago:

Morning thoughts... While attention has been fixed on the record-setting AO+ regime that saw the AO reach a preliminary all-time record of +6.342, another development that has occurred in the eastern Pacific has increased the probability of a warmer than normal March. That development also suggests that any snowfall in the Middle Atlantic region after February could be limited. ENSO Region 1+2 has warmed dramatically over the past two weeks. During the week centered around January 22, the ENSO Region 1+2 anomaly was -0.2°C and for January 2020 it was -0.04°C. During the most recent period (week centered around February 5), that anomaly had risen to +0.8°C. Both the 2/12/2020 0z EPS and GEFS suggest that the AO will return to extremely positive values near or above +4.000 around February 20. In addtion, based on the outcomes following the 1989 and 1990 super AO+ regimes in February and assuming a secondary peak at extremely positive values (+4.000 or above) around February 20 +/- a few days, March will likely begin with a noted absence of blocking in the AO+ region. The evolution of the February AO+ regime would argue that the AO would likely remain positive for much of March. During the 1981-2019 period, there were seven cases where the February ENSO Region 1+2 anomaly increased by +0.5° over the January average: 1989, 1991, 2002, 2006, 2008, 2011, and 2012. Five (71%) of those cases had an AO+ to end February and start March: 1989, 2002, 2008, 2011, and 2012. The March composite 500 mb and temperature anomalies for those five cases are below: Mean March-April snowfall for New York City for those five cases was 0.7" (skewed by 2.5" in March-April, 1989) and 0.5" in Philadelphia (skewed by 2.4" in March-April 1989).

Israel’s biggest snowfalls usually occur with an AO+.

JFK: 1972-73 1.6" 1997-98 3.6" 2011-12 3.7" 2001-02 4.5" 1994-95 7.9" 1988-89 8.2" 2006-07 8.5" 1989-90 9.6" 1996-97 9.8" NYC: 1972-73 2.8" 2001-02 3.5" 1918-19 3.8" 1931-32 5.3" 1997-98 5.5" 2011-12 7.4" 1877-78 8.1" 1988-89 8.1" 1900-01 9.1"

After another wet day, tomorrow will offer a brief reprieve from the precipitation. Nevertheless, more rain is likely tomorrow night into Thursday. A light accumulation of snow or sleet is possible in the far northern and western suburbs of New York City. Milder conditions will likely continue through Thursday. Afterward, a short-lived push of cold air could occur during the second half of the coming week into the weekend. Unlike with the prior Friday-Saturday cold shot, modified Arctic air will be involved, so minimum temperatures could fall into the teens in New York City and lower teens and perhaps single digits outside the City during the height of the cold. Afterward, warmer air will quickly return. It is likely that the February 15-21 period will be warmer than normal overall. Consistent with the pattern and supported by most of the guidance, no significant snowfalls (6" or more) are likely in the major Middle Atlantic cities through at least the first two weeks of February. There is a greater but still fairly low probability for Boston to see such a snowstorm. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.8°C for the week centered around January 29. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.07°C and the ENSO Region 3.4 anomaly has averaged +0.52°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was +3.12 today. Today, the preliminary Arctic Oscillation (AO) figure was +5.233. That figure exceeded the previous daily record high figure of +3.934, which was set in 1989. Near or just after mid-month, the guidance brings the MJO into Phase 6. There remains some uncertainty concerning its amplitude and duration in Phase 6. Its amplitude and the state of the teleconnections will determine the overall pattern during the start of the second half of February. During the February 10-29 period, when the MJO is in Phase 6 at low amplitude, the state of the PNA has the largest impact on temperatures in the Middle Atlantic region. For example, in New York City, the mean temperature for PNA+ cases during the 1981-2019 period was 34.1°. For PNA- cases, it was 41.7°. In contrast, when the MJO has an amplitude of 1.000 or above, the state of the AO is more important. During such cases, the mean temperature for AO+ cases was 40.9° while the mean temperature for AO- cases was 35.5°. The mean temperature for the entire February 10-29, 1981-2019 period was 36.5°. No significant stratospheric warming is likely through February 19, but the upper stratosphere above 5 mb will likely warm toward mid-February. Wave 2 activity will remain relatively suppressed. Overall, most of the stratosphere is forecast to remain cold on the EPS into the third week of February. On February 10, the MJO was in Phase 5 at an amplitude of 1.533 (RMM). The February 9-adjusted amplitude was 1.736. Based on sensitivity analysis applied to the latest guidance, there is an implied 87% probability that New York City will have a warmer than normal February and an implied 59% probability that February 2020 will be among the 10 warmest such months on record. Finally, a sizable majority (>80%) of years in which the AO has been, on average, strongly positive during the first 15 days of February, as appears very likely this month, were followed by ridging in the means in part or all of the eastern CONUS during March. Therefore, a warmer than normal March appears to be a likely scenario.

Allentown has had just 3 winters with less than 10" seasonal snowfall: 1972-73: 7.4" 1997-98: 7.7" 2001-02: 9.7"

IMO, the GEFS should not be changed to FV3 as long as the documented issues with the GFS persist. Moreover, serious consideration should be given as to whether the move to FV3 makes sense, along with a thorough review of alternative options. With new supercomputing capability, there's little reason not to give genuine consideration to alternative paths. https://www.noaa.gov/media-release/noaa-kicks-off-2018-with-massive-supercomputer-upgrade Unfortunately, my worry is that the "sunk cost fallacy" will constrain thinking among those who make the ultimate choices. If that happens and the performance gap between U.S. modeling and international modeling widens--and the ECMWF, UKMET, and CMC are continuing to make improvements--there will be a risk of a broad loss of confidence in U.S. modeling. That bad scenario would have adverse consequences of its own. That the GFS was the single global model to report a decline in skill in 2019 is troubling. That the impact of such an adverse development may be discounted in favor of pursuing the path chosen when real issues exist is even more troubling.

Afternoon thoughts... 1. There remains little indication that the Middle Atlantic region's growing snow drought (Washington, DC to New York City) will be dented by any significant snowfall for at least the next 7-10 days. 2. The guidance continues to differ concerning the MJO, but under most scenarios, whether the MJO will be in Phase 5 or 6 will make little difference. The AO+ should allow for warmer than normal conditions to prevail. 3. The extended range GFS idea of severe cold approaching the East and the GEFS idea of cold covering all of Canada and most of the CONUS are suspect. 4. The base case, which has support from the EPS and, to some extent the latest CFSv2 weekly guidance, is that the second half of February will wind up warmer to much warmer than normal in the Middle Atlantic and southern New England regions, even considering the short-lived shot of modified Arctic air to start that period.

As with others, I'm also happy to learn that your co-workers are all right.

This is disappointing. From having read his past tweets, it’s difficult to see any rational basis for the suspension.