donsutherland1

Some excerpts from a timely interview with Penn State University climate scientist Michael Mann: JAISAL NOOR: So you actually traveled to Australia to study the links between climate change and extreme weather events. You didn’t go to cover what’s happening now, but describe what you have discovered since you’ve been there. MICHAEL MANN: Yeah. It’s a bit surreal, because this trip, this sabbatical, was more than a year in the making. And indeed my goal was to come here to Australia to collaborate with some Australian scientists and understanding the scientific linkages between climate change and extreme weather events in Australia. And of course, ironically I arrived at the time that Australia was experiencing perhaps the most extreme weather on record in the form of unprecedented heat across the continent. And of course these unprecedented bush fires that are literally spreading across the continent. I’ve witnessed these impacts firsthand here in Sydney where I’m staying. Yesterday, I couldn’t go outside and take my usual daily run because the air quality was dangerous from all the smoke that was blowing in from these wildfires. And so here in Sydney, climate change isn’t just some theoretical construct. It’s something that is playing out in real time. I can look out my window and see it... JAISAL NOOR: Now have we reached a tipping point when it comes to climate change and these catastrophes that are unfolding not only in Australia but you see around the world. You see this growing devastation that natural disasters are causing. And is it possible to reverse this at this point? What would that look like? MICHAEL MANN: Yeah, so there is the danger of tipping points. You know when things get dry enough and hot enough, you can see a very dramatic escalation of these wildfires and bush fires here in Australia. And arguably that’s what we’re seeing in California and the Western US. That’s what we’re seeing here in Australia and in any many other regions around the world where summers are getting hot enough and dry enough that you just see this almost exponential escalation in these wildfires. So we may indeed be starting to cross a tipping point where, in the very best case, we are dealing with the new norm. That is to say, if we stop warming the planet and we sort of stabilize temperatures, we don’t worsen the problem. https://therealnews.com/stories/australia-fire-denying-climate-change-wont-save-you

Earlier today, Lexington and Louisville both set daily record high temperatures of 67° today. That warmth is coming northward and a very warm weekend lies ahead. Temperatures will likely peak in the 60s as far north as southern New England. At the same time, a storm will be bringing exceptionally heavy precipitation to the Great Lakes Region. Heavy snow is possible in Milwaukee. Very heavy rain will likely impact Chicago and Detroit. In fact, there is a chance that tomorrow's daily rainfall in Detroit could be the heaviest on record for January. The January record precipitation for Detroit is 1.76", which was set on January 12, 1908. This outcome is consistent with a very high amplitude MJO passage through the Maritime Continent phases. Since 1974, there were four cases when the MJO moved through Phase 4 with an amplitude of 2.000 or above accompanied by a positive Arctic Oscillation (AO), as is the case this January. The mean highest temperature during the MJO's passage through the Maritime Continent for New York City for those cases was 62.5°. Three of the four cases had peak temperatures of 60° or above. 2007 was the warmest with a high temperature of 72°. Tomorrow could see some locations approach or reach record high temperatures. Daily records for January 11 are: Atlantic City: 62°, 2018 Bridgeport: 56°, 1975 Hartford: 60°, 1983 Islip: 60°, 1975 New York City: 63°, 1975 Newark: 66°, 1975 Poughkeepsie: 63°, 1975 White Plains: 57°, 1975 Sunday will likely see widespread near record to record warmth. Daily records for January 12 are: Atlantic City: 67°, 2017 Bridgeport: 55°, 2017 and 2018 Hartford: 60°, 2018 Islip: 58°, 1995 and 2017 New York City: 66°, 2017 Newark: 67°, 2017 Poughkeepsie: 62°, 2018 White Plains: 63°, 2017 Sunday will mark the climax of January's warmth. Generally warmer than normal conditions will likely persist through mid-month, but the readings will be cooler than those of this weekend. There are growing indications of a pattern change beyond the medium-term. Near January 20 +/- a few days, somewhat colder air could return for a period. The closing week of the month could see a sustained colder pattern develop, possibly with a shot of Arctic air. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around January 1. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°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 +13.57 today. Today, the preliminary Arctic Oscillation (AO) figure was +2.516. The AO will likely average +2.000 or above during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000. No significant stratospheric warming event appears likely through January 18. Following some warming, the upper stratosphere will cool late in the period. Wave 2 activity will remain relatively suppressed just past mid-January. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 9, the MJO was in Phase 4 at an amplitude of 3.026 (RMM). The January 8-adjusted amplitude was 2.617. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into at least the start of February. Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were January three cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period would be colder than normal overall. In addition, an MJO in Phase 7 at an amplitude of 2.000 or above typically sees measurable snowfall consistent with overall January 16-31 climatology. That would imply approximately 2 measurable snow events for Philadelphia to New York City and 2-3 such events for Boston during the closing two weeks of January. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 84% probability of a warmer than normal January.

There has definitely been arson. However, the disinformation being circulated is a claim that 90% or more of the fires are the result of arson (not lightning, not accident, etc.).

At 1:55 PM EST, daily precipitation at Indianapolis had reached 1.30". That broke the daily record for January 10 of 1.29", which had been set in 1924.

Yes, I did read about how the bots are spreading disinformation. Social Media platforms may be the battleground where the dying climate denial movement is making its last stand. Science has already triumphed in the research publications field (though pseudo-journals may be launched to try to create confusion) and it has made major gains among numerous media outlets (except mainly for ideology- or interest-driven ones). Nevertheless, ignorance-driven movements typically prove unsustainable in the long-term when knowledge becomes widely-diffused. Unfortunately, when it comes to addressing the challenges of anthropogenic climate change, early significant progress is needed, due to the long atmospheric residence of some greenhouse gases and the increase in forcing associated with their increasing atmospheric concentration. There is real urgency for society--on a global basis--to begin to make serious efforts to address the challenge. But, for now, with some exceptions, there remains a leadership deficit and the impact of that deficit is compounded by the noise of the shrinking but still loud climate change denial movement (and the interests, some with vast financial resources, that have a vested stake in its goals).

The 1967 storm was really special.

Chicago appears to be in line for a relatively uncommon January precipitation event where 1.50" or more rain falls over a two-day period. The 500 mb pattern is a classic one for high precipitation events in January when the Arctic Oscillation is positive: Since 1871, Chicago has had just 16 storms bring 1.50" or more precipitation over a two-day period in January. It has had only 5 storms bring 2.00" or more precipitation over a two-day period in January.

This morning, temperatures were broadly warmer than they were yesterday at the same time. Moreover, in a number of locations, temperatures had been rising since midnight. Select 6 am temperatures and the 24-hour change are below: Allentown: 26° +6° Atlantic City: 36° +13° Baltimore: 35° +11° Bridgeport: 37° +14° Harrisburg: 29° +6° Islip: 41° +18° New York City: 37° +13° Newark: 31° +7° Philadelphia: 33° +9° Poughkeepsie: 30° +9° Washington, DC: 39° +9° White Plains: 34° +13° As warmer air continues to stream into the region, the temperature will likely reach 50° or above in much of the region before the end of the day.

As per the EU’s Copernicus, 2019 was the second warmest year on record: https://climate.copernicus.eu/surface-air-temperature-december-2019

Back on December 26, composite date for MJO passage at high amplitude in Phase 4 and historic data associated with strong AO+ patterns in combination with a positive EPO implied that the GEFS was missing what would become a strong ridge in the East during the January 10-17 period. We now know the unfortunate ending to that chapter of Winter 2019-2020. We will feel the full consequences this weekend as the mercury approaches or sets record high temperatures in the region. But is this the end of the story of Winter 2019-2020? The GEFS keeps things on pause for the most part. But, just as had been the case back in December, the GEFS could be mishandling the pattern in the extended range. Certainly, if the bias-corrected GEFS forecast for the MJO is accurate, the forecast 500 mb pattern would be suspect. The bias-corrected GEFS is suggesting that the MJO will move into Phase 7 at a super high amplitude (2.000 or above). Such an outcome typically produces a trough in the East and often a ridge in the EPO-PNA domains. Historic experience with the MJO following its reaching Phase 4 at an amplitude of 1.500 or above during the January 5-20 period (as occurred recently) sees the MJO progress into Phases 7 and 8 (88% cases). Both the GEFS and bias-corrected GEFS have recently adjusted to show the MJO moving into Phase 7 at high amplitude. The EPS has made some movement in that direction, as well. Additonal evidence also suggests that something closer to the more typical 500 mb pattern for the MJO in Phase 7 at a super high amplitude than the GEFS idea is the more likely scenario: 1. The 12z EPS moved toward such a pattern following hour 270. 2. The 12z CFSv2's Week 3 forecast had a similar 500 mb pattern to that shown on the EPS, except that the ridge-trough axes were displaced somewhat to the west. 3. Historic outcomes 3-4 weeks following the MJO's reaching Phase 4 at an amplitude of 1.500 or above during January 5-20 were generally 10°-12° colder than the Week 1-2 anomaly. Based on the latest guidance (estimated 40.0° mean temperature for the January 8-21 period in New York City), that would imply a January 22-February 3 mean temperature around 28.0°-30.0° at Central Park. That would be several degrees below normal. The recent weekly CFSv2 data was even colder than that. Key Points: 1. A preponderance of data is pointing to the return of winter in the East. 2. January could close with a sustained cold pattern that could continue into at least part of February. 3. Historic data from the past cases where the MJO entered Phase 7 at super high amplitude referenced above often saw above to much above normal snowfall in the Middle Atlantic and southern New England regions during February.

This weekend’s near record to record warmth skews the 8-day anomaly.

With low temperatures in the lower and middle 20s and highs only in the 30s, today offered a reminder that the calendar now reads "January." The reminder will be fleeting. This afternoon, warmer air had pushed into the Chicago area. As a result, the temperature rose to 50° after a morning low temperature of 23°. That warmer air will begin returning to the Middle Atlantic region overnight. As the warmer air comes northward, temperatures could begin to rise prior to sunrise. This weekend could be particularly warm as temperatures peak in the 60s as far north as southern New England. This outcome is consistent with a very high amplitude MJO passage through the Maritime Continent phases. Since 1974, there were four cases when the MJO moved through Phase 4 with an amplitude of 2.000 or above accompanied by a positive Arctic Oscillation (AO), as is the case this January. The mean highest temperature during the MJO's passage through the Maritime Continent for New York City for those cases was 62.5°. Three of the four cases had peak temperatures of 60° or above. 2007 was the warmest with a high temperature of 72°. Sunday could see near record to perhaps even record warmth in parts of the region. Daily records for January 12 are: Atlantic City: 67°, 2017 Bridgeport: 55°, 2017 and 2018 Islip: 58°, 1995 and 2017 New York City: 66°, 2017 Newark: 67°, 2017 Poughkeepsie: 62°, 2018 White Plains: 63°, 2017　 Generally warmer than normal conditions will likely persist through mid-month even beyond the coming weekend's exceptional warmth. However, there are growing indications of a pattern change beyond the medium-term. Near January 20 +/- a few days, somewhat colder air could return for a period. The closing week of the month could see a sustained colder pattern develop, possibly with a shot of Arctic air. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around January 1. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°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 +7.97 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.209. Through the first 40 days of meteorological winter, the AO has averaged +1.073. The AO will likely average +2.000 or above during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000. No significant stratospheric warming event appears likely through January 17. Following some warming, the upper stratosphere will cool late in the period. Wave 2 activity will remain relatively suppressed just past mid-January. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 8, the MJO was in Phase 4 at an amplitude of 2.611 (RMM). The January 7-adjusted amplitude was 2.273. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into at least the start of February. Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were January three cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period would be colder than normal overall. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 82% probability of a warmer than normal January.

Quick pattern evolution thoughts... The base case as per historical data has been that the MJO would progress into Phases 7 and then 8. More of the guidance is showing a move into Phase 7 in the extended range. The GEFS and bias-corrected GEFS show the MJO moving into Phase 7 at an amplitude > 2.000. Passage of the MJO into and through Phase 7 at very high amplitudes during the second half of January have typically seen trough development in the East and a snowy February. These developments suggest that the potential for a pattern change away from the much above normal warmth (with short breaks) for the first half of January are increasing for the second half of the month. The closing week has the potential to see the onset of a sustained colder pattern.

This morning, temperatures in the region were mainly in the lower and middle 20s. 6 am temperatures included: Bridgeport: 23° Danbury: 19° Islip: 23° New York City: 24° Newark: 24° Philadelphia: 24° Poughkeepsie: 21° White Plains: 21°

It appears that the shrinking climate change denial movement--what's left of it--is becoming downright nasty and condescending, especially toward women who have vast expertise in the field (including those on the forefront of research). One Twitter exchange that highlights the problem: https://twitter.com/JacquelynGill/status/1214367143837544448 Let's take a look at the two women who were told they should "spend some time in meteorology and climatology classrooms" via Twitter. Dr. Jacquelyn Gill is an ice age expert with extensive published peer-reviewed research: https://scholar.google.com/citations?user=KAZsZhIAAAAJ&hl=en&oi=ao Dr. Kate Marvel is a NASA climate scientist with a PhD in theoretical particle physics. She has an extensive range of published peer-review research: https://scholar.google.com/citations?user=cC8JXpQAAAAJ&hl=en&oi=ao But what about the critic? The one who all but implied that the two women have little or no relevant knowledge? What about his body of research? The absence of a link to his peer-reviewed research is no accident. The critic has no peer reviewed research that can be found. Of course, that didn't stop him from telling Drs. Gill and Marvel to "spend some time" to learn about meteorology and climate. Put another way, expertise and evidence are irrelevant in the world of climate change denial. That world is endangered by expertise and evidence. This Social Media exchange is just another pathetic death rattle of a movement that has no relevant knowledge of climate/climate change and, therefore, no meaningful contribution to make to the scientific discourse. Despite its fatal flaws, it is desperate to overturn the now overwhelming body of evidence behind scientific understanding of anthropogenic climate change and its impacts. Thus, detours aimed at discrediting and delegitimizing climate scientists are pursued. Those efforts cannot succeed. The problem the climate change denial movement faces is that the public now has access to who has published peer-reviewed research. Thus, the public, or those who seek to be informed and who possess information literacy skills to pursue the facts, can readily sort out the genuine experts from the climate change denial bomb throwers who offer little but attacks. Spoiler alert: The experts are the very scientists being assailed.

Much colder air is continuing to push into the region. However, its stay will be short. By Friday, much warmer air will return to the region. The coming weekend could be particularly warm. There is a growing possibility that temperatures could soar into the 60s this weekend even into southern New England. Sunday could see near record to perhaps even record warmth in parts of the region. Daily records for January 12 are: Atlantic City: 67°, 2017 Bridgeport: 55°, 2017 and 2018 Islip: 58°, 1995 and 2017 New York City: 66°, 2017 Newark: 67°, 2017 Poughkeepsie: 62°, 2018 White Plains: 63°, 2017 Generally warmer than normal conditions will likely persist through mid-month even beyond the weekend's exceptional warmth. Near January 20 +/- a few days, somewhat colder air could return for a period. There remains potential that the closing week of the month could see a sustained colder pattern develop. The progression of the MJO, state of the teleconnections, and position of what will likely remain a strong polar vortex will shape the long-range pattern evolution. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around January 1. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°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 +4.10 today. Today, the preliminary Arctic Oscillation (AO) figure was +4.048. That was the highest AO figure since December 22, 2016 when the AO was +4.511. This was also the highest January AO reading since January 25, 2008 when the AO was +4.458. It appears that the AO will likely average +2.000 or above during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000. No significant stratospheric warming event appears likely through January 16. Following some warming, the upper stratosphere will cool late in the period. Wave 2 activity will remain suppressed through mid-January. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 7, the MJO was in Phase 4 at an amplitude of 2.270 (RMM). The January 6-adjusted amplitude was 1.599. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into the start of February. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 84% probability of a warmer than normal January.

For those who are interested, 12z EPS temperatures for NYC (January 16-20): January 16: 48-36 January 17: 38-29 January 18: 34-25 January 19: 32-22 January 20: 32-20 Of course things can change at that timeframe, but at least one isn't dealing with a seemingly endless stretch of unseasonable warmth on that run.

FWIW, the above Day 11 analog composite was based off the 0z GEFS. Since then, the GEFS has slowly begun to shift toward a less hostile pattern. Tomorrow's analog set could provide insight into the early stages of the GEFS' evolution.

Hopefully, after early this coming weekend and early next week, the worst of the warmth will be over. Even transitional patterns can have opportunities for snowfall, so things could get more interesting as the month progresses.

As noted previously, the base case from historical data is that the MJO will likely progress into Phases 7 and 8 in the extended range (88% of cases where the MJO reached Phase 4 at an amplitude of 1.500 or above during the January 5-20 period). The shift in the MJO, even with lags, should start manifesting itself in some hemispheric changes. The new GEFS is beginning to reflect some of the changes that could take place. The EPS has been suggesting a pattern change for some time. Questions about the length of the transition and timing of perhaps sustained cold remain to be resolved.

Verification Atlantic City: Initial: 1" or less; Final: 1" or less; Actual: Trace (within range) Baltimore: Initial: 1"-2"; Final: 1"-3"; Actual: 1.5" (within range) Harrisburg: Initial: 1" or less; Final: 1" or less; Actual: 3.9" Islip: Initial: 0.5" or less; Final: 1" or less; Actual: 0.4" (within range) New York City: Initial: 0.5" or less; Final: 0.5" or less; Actual: 0.0" (within range) Newark: Initial: 0.5" or less; Final: 0.5" or less; Actual: Trace (within range) Philadelphia: Initial: 1" or less; Final: 1" or less; Actual: Trace (within range) Sterling: Initial: 1"-3"; Final: 1"-3"; Actual: 2.0" (within range) Washington, DC: Initial: 1"-2"; Final: 1"-3"; Actual: Trace Wilmington, DE: Initial: 1"-2"; Final: 1"-2"; Actual: Trace Note: Since January 1, 1950, Washington, DC (DCA) has never recorded measurable snowfall in January when the AO was +3.500 or above.

A storm responsible for bringing snow to parts of the Middle Atlantic region will bring some rain and wet snow to parts of the region overnight. Parts of New Jersey and Long Island could pick up 1"-3" snow in a few spots. Most of the region will likely see 0.5" or less. Snowfall amounts included: Baltimore: 1.5"; Harrisburg: 2.9"; Sterling: 2.0"; and, Washington, DC (DCA): Trace (0.5" was reported in Alexandria). New York City will finish with a mean temperature near 41.0° during the first week of January once the daily low temperature is reached near midnight. Since 1869, there were 23 prior cases when the first week of January had a mean temperature of 40° or above in New York City. In 17 (74%), January wound up warmer than normal and in 12 (52%), January had a mean temperature of 35° or above. The average monthly temperature for January for all 23 cases was 36.0° (median temperature: 35.6°). A short-duration fairly sharp cold shot is possible tomorrow and Thursday. The approach and passage of the Arctic front could trigger snow showers and even some heavier snow squalls tomorrow. The light snowfall unfolding today and tonight is consistent with historic experience during very strong AO+ patterns during the first half of January. Based on the forecast strongly positive AO, the probability of a significant (6" or greater snowstorm) for the major cities of the Middle Atlantic region during the first 10 days of January is low. Since 1950, the biggest snowfall for that region when the AO was +2.000 or above during the January 1-15 period occurred during January 14-15, 1954 when Philadelphia received 3.0" snow and New York City picked up 2.0". Boston has had numerous 6" or greater snowstorms during such cases, including one 10" or greater snowstorm. Therefore, the risk of significant snow would likely be greatest over New England assuming this relationship holds (no significant offsetting variables). Following the brief cold shot, ridging with warmer than normal temperatures will develop and persist through at least mid-month. There is a growing possibility that temperatures could soar into the 60s this weekend even into southern New England. Beyond that, there is the potential that the closing part of the month could see a colder pattern develop. The progression of the MJO and state of the teleconnections will determine the pattern evolution for the second half of the month. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around January 1. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°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 +5.00 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.662. That was the highest AO figure since December 23, 2016 when the AO was +3.807. No significant stratospheric warming event appears likely through January 15. Following some warming, the upper stratosphere will cool late in the period. Wave 2 activity will remain suppressed through mid-January. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 6, the MJO was in Phase 4 at an amplitude of 1.591 (RMM). The January 5-adjusted amplitude was 0.904. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 84% probability of a warmer than normal January.

As of 4 pm, Sterling (IAD) had picked up 1.7" snow. Precipitation in the greater Washington area should be winding down over the next 1-2 hours. Based on observations, the edge of the accumulating snow had come farther north than shown on some of the modeling. As a result, Harrisburg had several periods of heavy snow. This may imply that a slice of Long Island (most likely Suffolk County) could see 1"-3" snow as the storm tracks well south and east of the New York City area. Islip could approach or reach the lower part of that range. Over the course of the evening, light precipitation should change to snow in Philadelphia and Wilmington as temperatures fall. Atlantic City still looks likely to see 1" or less of snow, as the changeover could be too late to allow for much more to accumulate. At 4 pm, the temperature there was still a balmy 45°.

Some quick thoughts on the long-range pattern evolution... 1. The GEFS remains stuck with essentially the western trough-eastern ridge pattern. 2. The EPS appears to have accelerated the onset of a colder pattern. Both ideas are actually problematic. First, the base case from historical data is that the MJO will likely progress into Phases 7 and 8 in the extended range. The GEFS idea seems not to reflect that development. The shift in the MJO, even with lags, should start manifesting itself in some hemispheric changes. Second, in past cases where strong AO+/PNA- regimes rapidly collapsed, the period of troughing in the East was often short-lived (late January 2000 followed by February 2000 provide an illustration). Also worrisome is that strong polar vortex that is shown on the extended range of the EPS. There would be a risk that its persistence would lead to a scenario where above normal 500 mb heights are elongated and eventually stretch across the CONUS with the coldest air being bottled up mainly in Canada (with only some transient shots). Overall, I still think a slower pattern evolution still makes more sense, especially if the MJO progresses as typically is the case following very high amplitude passage through Phase 4 during the January 5-20 period. Colder shots would be transient until perhaps the closing week of January and then more sustained cold could develop. Interestingly enough, some of the recent CFSv2 weekly forecasts show such a situation.

Capitol Camera (U.S. Senate): https://www.senate.gov/general/capcam.htm